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number: PE 303.110
This document is a working Document for the 'STOA Panel'. It is not an official publication of STOA.
This document does not necessarily represent the views of the European Parliament 1. Letter to the reader
Dear Reader,
The study you are about to read was prepared by an external contractor, WISE-Paris, in the context of the STOA Workplan 2000 on the basis of a request submitted by the European Parliament's Committee on Petitions. At its meeting of 23 October 2001, the STOA Panel, which is responsible for all political decisions related to the work of STOA, took note of the study submitted by the contractor and agreed to publish it as a first contribution to the scientific debate on the possible toxic effects from the nuclear reprocessing plants in Sellafield (UK) and Cap de la Hague (France).
According to the decision of the Panel, the study is being published together with the evaluation reports of three experts, whose opinion was formally requested by the STOA Panel. The Panel decided on 21 June 2001 to request the opinion of independent experts after discussing the concerns expressed by some Members of the European Parliament in relation to the possible lack of objectivity of the study by WISE-Paris. On 23 October, the Panel took note of the opinions expressed by the reviewers and found it appropriate to communicate this information to the public, as agreed by the reviewers.
I would point out that, as is the case with all studies commissioned by STOA, publication of this study does not imply adoption of its contents and these do not necessarily reflect the views of member of the STOA Panel or the European Parliament.
In the context of its open approach, the Panel is prepared, if requested by a parliamentary committee, to proceed to a supplementary study, which will take due account of the opinions of political and social groups concerned, as well as of a wide range of prominent scientists in the fields relevant to the subject. The new study should be seen as an additional contribution to the effort of STOA to enrich the political debate with the most objective and comprehensive scientific and technical information possible on this subject.
The STOA Panel further agreed to encourage the Petitions Committee to organise a public hearing on the subject, at a time that the committee will consider appropriate, in collaboration with STOA, as well as, if the committee so decides, with other interested committees of the European Parliament. Such a hearing would give an opportunity to all interested parties to formulate their positions and provide all data necessary to support them. The Panel places great value in an open event of this kind, as the best way of treating a subject on which significantly divergent opinions may exist.
Finally, the STOA Panel expresses regret that WISE-Paris saw fit to break the confidentiality clause in its contract with the European Parliament by making public parts of the study prior to publication. This behaviour of WISE-Paris is not in line with the long-standing tradition of STOA, which has always endeavoured to associate its work with the highest scientific and ethical standards.
Yours sincerely,
Professor Antonios TRAKATELLIS, MD, PhD
Chairman of the STOA Panel
TOC \o "1-5" 1. LETTER TO THE READER 3
2. STUDY BY WISE-PARIS ............................................................................................................5
Executive Summary and General conclusions 9
1. Introduction PAGEREF _Toc524143404 \h 9
2. Reprocessing Status and Issues PAGEREF _Toc524143405 \h 9
3. International and European Legal Framework PAGEREF _Toc524143406 \h 9
4. Risk Assessment of Radioactive Releases PAGEREF _Toc524143407 \h 10
5. Case Study Sellafield PAGEREF _Toc524143408 \h 11
6. Case Study La Hague PAGEREF _Toc524143409 \h 13
7. Comparative and Cumulative Analysis PAGEREF _Toc524143410 \h 15
8. Alternative Options PAGEREF _Toc524143411 \h 15
General Conclusions .......................................................................................................................... 16
1. Introduction PAGEREF _Toc524143412 \h 17
1.1. Objective of the Study PAGEREF _Toc524143413 \h 17
1.2. Background and Chronology of the Project PAGEREF _Toc524143414 \h 18
2. Reprocessing Status and Issues PAGEREF _Toc524143415 \h 19
2.1. Nuclear Reprocessing PAGEREF _Toc524143416 \h 19
2.2. Origins of Reprocessing PAGEREF _Toc524143417 \h 19
2.3. Implications of Reprocessing PAGEREF _Toc524143418 \h 20
3. International and European Legal Framework PAGEREF _Toc524143419 \h 21
3.1. International Legislation and Treaties PAGEREF _Toc524143420 \h 21
3.1.1. Major International Bodies PAGEREF _Toc524143421 \h 21
3.1.2. Major International Conventions PAGEREF _Toc524143422 \h 21
3.1.3. The European Legal Framework And Its Implementation PAGEREF _Toc524143423 \h 22
3.1.3.1. Euratom Treaty PAGEREF _Toc524143424 \h 22
3.2. Marine Pollution - Application of the Precautionary Principle PAGEREF _Toc524143425 \h 26
4. Risk Assessment of Radioactive releases PAGEREF _Toc524143426 \h 28
4.1. Releases from Reprocessing PAGEREF _Toc524143427 \h 28
4.2. Collective Doses PAGEREF _Toc524143428 \h 28
4.2.1. Introduction PAGEREF _Toc524143429 \h 28
4.2.2. Theoretical Justification PAGEREF _Toc524143430 \h 28
4.2.3. Global Collective Doses PAGEREF _Toc524143431 \h 29
4.2.4. Important Radionuclides in Reprocessing Releases PAGEREF _Toc524143432 \h 29
4.2.4.1. Carbon-14 (14C) PAGEREF _Toc524143433 \h 29
4.2.4.2. Krypton-85 (85Kr) PAGEREF _Toc524143434 \h 29
4.2.4.3. Iodine-129 (129I) PAGEREF _Toc524143435 \h 29
4.2.4.4. Tritium (3H) PAGEREF _Toc524143436 \h 30
4.2.4.5. Technetium-99 (99Tc) PAGEREF _Toc524143437 \h 30
4.3. Uncertainties in Risk Assessment PAGEREF _Toc524143438 \h 31
5. Case Study Sellafield PAGEREF _Toc524143439 \h 33
5.1. National Regulatory Framework PAGEREF _Toc524143440 \h 33
5.2. Operations at Sellafield PAGEREF _Toc524143441 \h 33
5.3. Releases from Sellafield PAGEREF _Toc524143442 \h 34
5.3.1. Air Emissions PAGEREF _Toc524143443 \h 34
5.3.2. Liquid Discharges PAGEREF _Toc524143444 \h 35
5.3.3. Technetium Discharges PAGEREF _Toc524143445 \h 37
5.3.4. Expected Future Sellafield Discharges PAGEREF _Toc524143446 \h 37
5.4. Impact of Sellafield Discharges PAGEREF _Toc524143447 \h 39
5.4.1. Plutonium and other actinides near Sellafield PAGEREF _Toc524143448 \h 39
5.4.2. Estimated Doses from Consumption of Irish Sea Fish and Shellfish PAGEREF _Toc524143449 \h 40
5.4.3. Doses to Critical Groups PAGEREF _Toc524143450 \h 40
5.4.4. Environmental Concentrations PAGEREF _Toc524143451 \h 40
5.4.4.1. Changes between 1989-1999 PAGEREF _Toc524143452 \h 40
5.4.4.2. Detailed Concentrations in Fish, Shellfish, Sediments and Aquatic Plants PAGEREF _Toc524143453 \h 41
5.4.5. Technetium Concentrations PAGEREF _Toc524143454 \h 41
5.4.5.1. Technetium-99 Concentrations in Marine Samples PAGEREF _Toc524143455 \h 41
5.4.5.2. Uptake of Technetium-99 by Marine Plants and Animals PAGEREF _Toc524143456 \h 42
5.4.6. Conclusions on Concentrations and Doses PAGEREF _Toc524143457 \h 43
5.5. The Hazard Posed by Liquid High Level Waste at Sellafield PAGEREF _Toc524143458 \h 44
5.6. Health Effects at Sellafield PAGEREF _Toc524143459 \h 46
5.6.1. Childhood Leukemia at Seascale PAGEREF _Toc524143460 \h 46
5.6.2. Paternal Pre-Conception Irradiation PAGEREF _Toc524143461 \h 47
5.6.3. Population Mixing PAGEREF _Toc524143462 \h 47
5.6.4. Other Possible Health Effects at Sellafield PAGEREF _Toc524143463 \h 47
5.6.5. Conclusions on Health Effects PAGEREF _Toc524143464 \h 48
6. Case Study La Hague PAGEREF _Toc524143465 \h 49
6.1. National Regulatory Framework PAGEREF _Toc524143466 \h 49
6.1.1. Authorisations of discharges PAGEREF _Toc524143467 \h 49
6.1.2. Licensing Procedures PAGEREF _Toc524143468 \h 50
6.1.3. Supervision PAGEREF _Toc524143469 \h 51
6.1.4. Radioprotection PAGEREF _Toc524143470 \h 51
6.1.5. References to International Legislation PAGEREF _Toc524143471 \h 52
6.2. Operation at La Hague PAGEREF _Toc524143472 \h 52
6.2.1. Reprocessing at La Hague PAGEREF _Toc524143473 \h 52
6.2.2. Waste Production of La Hague PAGEREF _Toc524143474 \h 53
6.2.2.1. Low Level Waste (LLW) PAGEREF _Toc524143475 \h 55
6.2.2.2. Intermediate Level Waste (ILW) PAGEREF _Toc524143476 \h 55
6.2.2.3. High Level Waste (HLW) PAGEREF _Toc524143477 \h 55
6.2.2.4. Curie-swap PAGEREF _Toc524143478 \h 55
6.2.2.5. Reprocessing at La Hague and HLW long-term management PAGEREF _Toc524143479 \h 55
6.3. Discharges from La Hague PAGEREF _Toc524143480 \h 56
6.3.1. Authorisations PAGEREF _Toc524143481 \h 56
6.3.2. Discharge levels of major radionuclides PAGEREF _Toc524143482 \h 59
6.3.3. Discharge trends PAGEREF _Toc524143483 \h 60
6.3.4. Unplanned Radioactive Releases PAGEREF _Toc524143484 \h 60
6.3.4.1. Major accidents and list of incidents at La Hague plant PAGEREF _Toc524143485 \h 60
6.3.4.2. Potential Hazards at the La Hague plant PAGEREF _Toc524143486 \h 60
6.4. Environmental Concentrations and Doses PAGEREF _Toc524143487 \h 61
6.4.1. Environmental Concentrations PAGEREF _Toc524143488 \h 61
6.4.2. Doses from Environmental Radiation PAGEREF _Toc524143489 \h 62
6.5. Impact of La Hague Discharges Background Studies PAGEREF _Toc524143490 \h 62
6.5.1. Marine effects PAGEREF _Toc524143491 \h 62
6.5.2. Health Effects PAGEREF _Toc524143492 \h 63
6.5.2.1. Cancer morbidity inquiry in the Manche Department PAGEREF _Toc524143493 \h 63
6.5.2.2. Epidemiological study by Viel and Pobel PAGEREF _Toc524143494 \h 63
6.5.2.3. The Radioecological Group of North-Cotentin (GRNC) survey PAGEREF _Toc524143495 \h 63
6.5.2.4. La Hague Childhood Leukaemia Study 2001 PAGEREF _Toc524143496 \h 65
6.5.2.5. Radiological impacts of spent nuclear fuel management options, NEA, 2000 PAGEREF _Toc524143497 \h 65
6.5.3. Uncertainties in Dose Assessments PAGEREF _Toc524143498 \h 65
6.5.3.1. A Mandate for the Radio-ecological Group of North-Cotentin to Assess Scientific Uncertainties PAGEREF _Toc524143499 \h 65
6.5.3.2. Sources of Uncertainties PAGEREF _Toc524143500 \h 66
7. Comparative and Cumulative Analysis PAGEREF _Toc524143501 \h 68
7.1. Comparison of Releases in 1999 from La Hague and Sellafield PAGEREF _Toc524143502 \h 68
7.2. Key Nuclides for Collective Dose Calculation PAGEREF _Toc524143503 \h 69
7.2.1. Carbon-14 PAGEREF _Toc524143504 \h 69
7.2.2. Krypton-85 PAGEREF _Toc524143505 \h 69
7.2.3. Iodine-129 PAGEREF _Toc524143506 \h 69
7.3. Collective Doses from Reprocessing Releases PAGEREF _Toc524143507 \h 70
7.3.1. Collective Doses from Reprocessing PAGEREF _Toc524143508 \h 70
7.3.1.1. European Doses PAGEREF _Toc524143509 \h 70
7.3.1.2. Global Doses PAGEREF _Toc524143510 \h 71
7.3.2. Commentary on Collective Doses from Sellafield and La Hague PAGEREF _Toc524143511 \h 71
7.3.3. Use in Comparative Studies PAGEREF _Toc524143512 \h 72
7.3.4. Use in Cost/Benefit Studies PAGEREF _Toc524143513 \h 72
7.3.5. Chapter Conclusions PAGEREF _Toc524143514 \h 73
8. Alternative Options PAGEREF _Toc524143515 \h 74
8.1. Waste Management Issues PAGEREF _Toc524143516 \h 74
8.1.1. Re-use of plutonium and uranium PAGEREF _Toc524143517 \h 74
8.1.2. Final volume of waste PAGEREF _Toc524143518 \h 75
8.2. Economics of Direct Disposal vs. Reprocessing PAGEREF _Toc524143519 \h 75
8.3. Dry Storage PAGEREF _Toc524143520 \h 77
9. Policy Options PAGEREF _Toc524143521 \h 78
9.1. Releases of Radioactive Wastes and Their Effects on the Environment and Health PAGEREF _Toc524143522 \h 78
9.2. Management of Non-Discharged Radioactive Wastes PAGEREF _Toc524143523 \h 80
9.3. Management of Plutonium Stocks PAGEREF _Toc524143524 \h 80
9.4. Development of Spent Fuel Management Alternatives PAGEREF _Toc524143525 \h 81
9.5. Development of Democratic Decision Making Tools PAGEREF _Toc524143526 \h 81
Annexes PAGEREF _Toc524143527 \h 82 TOC \t "TitleAnnex" \c
Annex 1 Excerpts from Petition 393/95 PAGEREF _Toc524143826 \h 83
Annex 2 International Conventions PAGEREF _Toc524143827 \h 84
Annex 3 OSPAR Convention PAGEREF _Toc524143828 \h 85
Annex 4 European Legislation, Regulation and Policy Statements PAGEREF _Toc524143829 \h 87
Annex 5 The Precautionary Principle: Not Using the Sea as an Experimental Laboratory PAGEREF _Toc524143830 \h 89
Annex 6 Background Information on Collective Dose PAGEREF _Toc524143831 \h 90
Annex 7 Individual Exposures from Consumption of Seafood around Sellafield PAGEREF _Toc524143832 \h 92
Annex 8 Concentration of Radionuclides in Seafoods from Sellafield PAGEREF _Toc524143833 \h 93
Annex 9a Environmental Concentrations of Nuclide Discharges from Sellafield PAGEREF _Toc524143834 \h 94
Annex 9b Environmental Concentrations of Nuclide Discharges from La Hague PAGEREF _Toc524143835 \h 100
Annex 10 Specific Radiobiological Issues PAGEREF _Toc524143836 \h 103
Annex 11 Possible Causes for the Discrepancy between Observed Cancers and Estimated Low Doses PAGEREF _Toc524143837 \h 106
Annex 12 Evolution of the Waste Stockpiles Managed at La Hague PAGEREF _Toc524143838 \h 108
Annex 13 The Return of Foreign Waste from Reprocessing at La Hague PAGEREF _Toc524143839 \h 109
Annex 14 Compared Discharge Limits of La Hague and a Typical Reactor Site PAGEREF _Toc524143840 \h 110
Annex 15 Compared Real Radioactive Discharges from La Hague and One PWR PAGEREF _Toc524143841 \h 111
Annex 16 Chronological List of 8 Significant Accidents at La Hague since 1968 PAGEREF _Toc524143842 \h 112
Annex 17 Incidents/Accidents at La Hague declared to the French Safety Authorities between 1989 and 2000 PAGEREF _Toc524143843 \h 114
Annex 18 Type of Accidents and Consequences at Reprocessing Sites PAGEREF _Toc524143844 \h 117
Annex 19 Comparison of Caesium-137 Contained in Spent Fuels Stored at La Hague and Released During the Chernobyl Accident PAGEREF _Toc524143845 \h 118
Annex 20 Concentration Factors for Selected Radionuclides PAGEREF _Toc524143846 \h 119
Annex 21 Comparison between the Morbidity Observed in the District of Cherbourg and in the District of Avranches PAGEREF _Toc524143847 \h 120
Annex 22 Individual Committed Dose for Six Reference Groups near La Hague (GRNC Estimates) PAGEREF _Toc524143848 \h 121
Annex 23 OECD Nuclear Energy Agency Dose Estimates for the Public and Workers for the Reprocessing and Direct Disposal Options PAGEREF _Toc524143849 \h 122
Annex 24 Assessment of the non-attributed activity of Iodine-129 at La Hague PAGEREF _Toc524143850 \h 123
Annex 25 Letter to Annie Sugier, President of the Radio-Ecological Group North-Cotentin, about Iodine 129 PAGEREF _Toc524143851 \h 124
Annex 26 Separation, Re-Use and Exportation of Plutonium in France PAGEREF _Toc524143852 \h 129
Annex 27 Material and Economic Balances over the French Reactor Lifetime - Direct Disposal vs. Reprocessing PAGEREF _Toc524143853 \h 130
Annex 28 Dry Storage Technologies PAGEREF _Toc524143854 \h 131
Annex 29 Dry Storage Economics PAGEREF _Toc524143855 \h 135
Annex 30 Data on Radionuclides PAGEREF _Toc524143856 \h 138
Glossary PAGEREF _Toc524143528 \h 139
Bibliography PAGEREF _Toc524143529 \h 142
List of Tables and Figures 155
. - . - . - .- .
3. EVALUATION REPORTS BY EXPERTS
Evaluation Report Croudace .................................................................................................................. 160
Evaluation Report Mitchell .................................................................................................................... 165
Evaluation Report Zerbib ...................................................................................................................... 168
Executive Summary and General conclusions
1. Introduction
The principal aim of this report is to assist the Committee of Petitions of the European Parliament in its consideration of Petition 393/95 brought by Dr. W. Nachtwey. The Petition expresses concerns about radioactive discharges from nuclear reprocessing plants at Sellafield in the UK and La Hague in France, and their possible adverse health effects. Six years after the Petition was introduced, the Petitioners main concerns remain relevant. This report concludes that reprocessing discharges are a valid matter for the Committees consideration. It also concludes that, on balance, the Petitioner's concerns over radioactive discharges from Sellafield and La Hague are justified.
The report presents evidence and data on:
radioactive discharges from the Sellafield and La Hague sites;
resulting nuclide concentrations in environmental media including foodstuffs;
radiation doses from nuclide discharges to critical groups near the sites;
adverse health effects near the two sites; and
resulting collective doses from nuclide discharges.
The report also examines a number of current issues in radiobiology concerning health effects from exposure to ionising radiation, in particular genetic and in utero effects.
In addition, in accordance with contract specifications, the report examines other major factors that might influence future decision-making on reprocessing. It provides information on the legal framework, the operational history of the plants and the economic case for reprocessing compared with available alternatives for spent nuclear fuel management. The report also makes policy-related recommendations that take into account current knowledge and uncertainties in risk assessment and the availability of alternatives to reprocessing in spent fuel management.
2. Reprocessing Status and Issues
Only 5% to 10% of world annual spent fuel arisings is submitted for reprocessing, with the rest stored pending final disposal in a repository. The largest centres in the world for commercial reprocessing remain Sellafield in the UK and La Hague in France. Reprocessing involves the dissolution of the spent fuel in boiling concentrated nitric acid and subsequent physico-chemical separations of uranium and plutonium. Multiple waste streams are created by these physical and chemical processes. While some wastes are retained and conditioned, considerable volumes of liquid and gaseous wastes are released to the environment. Reprocessing operations release considerably larger volumes of radioactivity than other nuclear activities, typically by factors of several 1,000 compared with nuclear reactors.
3. International and European Legal Framework
The report provides a brief overview of Major International Bodies that play a role in the development of international nuclear standards and the main International Conventions relative to nuclear reprocessing are presented.
The OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic, to which the European Commission is a Contracting Party, is of particular relevance to reprocessing activities. The OSPAR Commission has declared its commitment to the application of the precautionary principle, the polluter-pays principle, and to the application of Best Available Techniques (BAT) and Best Environmental Practice (BEP), including, where appropriate, Clean Technology. At the Sintra Meeting in 1998, Ministers agreed to reduce marine pollution with the ultimate aim of achieving concentrations in the environment near background values for naturally occurring substances and close to zero for man-made synthetic substances. They emphasised the importance of the Precautionary Principle in this work. It is notable that the commitment is to achieve concentrations in the environment close to zero, not merely concentrations in discharges. At the Copenhagen Meeting in June 2000, the OSPAR Commission voted unanimously (with the abstentions of the UK, France and the European Commission) that discharge authorisations be reviewed with a view to, inter alia: implementing the non-reprocessing option (for example dry storage).
The Euratom Treaty provides the basis for the European regulation of the nuclear sector. Article 34 requires Member States to obtain the opinion of the European Commission before they carry out dangerous experiments. According to the Commission, France has not requested the Commissions opinion under Article 34 concerning activities in La Hague nor has the UK as regards activities in Sellafield.
åð Conclusions on Dangerous Experiments
The Member States UK and France apparently have not complied with Article 34 of the Euratom Treaty, since they have never requested the European Commission s opinion under the article concerning any of their activities at Sellafield and La Hague.
Article 35 of the Euratom Treaty grants control rights to the European Commission for the verification of operation and efficiency of monitoring equipment at nuclear facilities. However, only one verification mission was carried out at Sellafield (1993) and La Hague (1996). These are considered to be outdated. Furthermore, the Commission is apparently highly dependent on information provided by Member States. It is equally doubtful whether the Commission is in a position to determine, as required under Article 37, whether the reprocessing activities are liable to result in the radioactive contamination of the water, soil or airspace of another Member State. In addition to the dependence on Member States information, the Commission spends only extremely limited manpower into the evaluation of nuclear projects (2 person-months in the case of reprocessing plants).
åð Conclusions on European Commission Responsibilities under Article 35 of the Euratom Treaty
The Commission s verification activities make ineffective use of its control rights over monitoring equipment. Statements by the Commission on monitoring at Sellafield and La Hague are not backed up by credible data. It is noted, however, that the Commission is currently reviewing its verification activities.
The Commission is apparently not in a position to guarantee that the Basic Safety Standards are respected concerning the La Hague and Sellafield facilities and to determine whether the reprocessing activities are liable to result in the radioactive contamination of the water, soil or airspace of other Member States.
4. Risk Assessment of Radioactive Releases
Radioactive discharges from both sites are very large and indeed rank among the largest anthropogenic sources of radioactivity to the world. As such they constitute a reasonable subject for enquiry by the Committee. Nuclides released to air and sea result in the contamination of food chains via a number of pathways. Individuals may also receive radiation doses from immersion in radioactive aerosols, inhalation of radioactive gases and particulate matter, and ground shine from nuclides deposited on land.
Various computer models have been designed to estimate radiation doses from nuclide releases to members of critical groups living near nuclear facilities. These calculated doses are used to regulate discharges from nuclear facilities.
However, this approach protects individuals and not populations. The use of collective doses has therefore been stipulated by various international bodies, including the European Commission in the Basic Safety Standards Directive (96/29). Crucial theoretical underpinning for collective dose was provided by the scientific communitys adoption of the Linear No-Threshold model for radiations adverse health effects. This states that there is no level of radiation exposure below which there is no effect: risks continue with declining doses until zero dose. Even the smallest possible dose, i.e. a photon passing through a cell nucleus, carries with it a risk of cancer. Although this is an extremely small risk, it is still a finite risk.
Collective dose estimates strongly depend on the size of the population considered and the time scale used. Opinions vary as to which populations and time scales should be used. Given the very long term half-lives of some radionuclides released by reprocessing plants (e.g. iodine 129, 16 million years) and their global distribution, there should be no time limits and dose evaluations should be global. There is no reason why future generations or distant populations should be any less protected than current generations in the vicinity of the facilities.
Comparisons of doses from nuclear activities with those induced by natural background radiation are flawed because, inter alia, these omit to indicate the health impact of background radiation itself. It has been estimated that natural background radiation results in about 6,000 to 7,000 UK cancer deaths per year in the UK with a similar figure for France.
åð Conclusions on Dose Estimates
In order to evaluate the risk of large releases of radionuclides into the environment, in addition to critical group dose estimates, collective dose calculations should be carried out and taken into account during decisions on the continued operation of reprocessing plants.
5. Case Study Sellafield
Between 1965 and the end of year 2000, about 26,000 tonnes of spent gas graphite fuel were reprocessed by the B205 line at Sellafield. About 3,000 tonnes of spent light water reactor fuel have been reprocessed at THORP since 1994. Based on current contracts and annual throughput rates, both plants are expected to shut down within the next 10 years or earlier.
Although gaseous releases of most nuclides from Sellafield have not varied to a marked extent since the 1970s, iodine 129 emissions have increased 10-fold. Radioactive marine releases of carbon 14, strontium 90 and caesium declined markedly in the early 1980s, while in the mid 1990s increases occurred in releases of carbon 14, cobalt 60, strontium 90, technetium 99 and iodine 129. Over the same period, actinide (mainly plutonium) discharges have declined markedly.
Internal BNFL documents suggest significant increases in nuclide releases in the future at Sellafield. For some worst case scenarios, the operator predicts for levels approaching or above the limits for sea discharges of over half the currently authorised radionuclides. A similar situation is expected for aerial releases.
åð Conclusions on Sellafield Releases
Increases of releases of key radionuclides from Sellafield in the late 1990s and expected future discharges are inconsistent with obligations under the OSPAR Convention.
The deposition of plutonium within 20 km of Sellafield attributable to aerial emissions has been estimated at 160-280 GBq (billion becquerels), that is two or three times plutonium fallout from all atmospheric nuclear weapons testing. In addition, significant quantities of radionuclides can become airborne in sea spray and be transported inland by the wind. The average activity due to actinides from the sea may occasionally exceed the international limit of 1 mBq/m3.
It has been estimated that over 40,000 TBq (trillion becquerels) of caesium-137, 113,000 TBq of beta emitters and 1,600 TBq of alpha emitters have been discharged into the Irish Sea since the inception of reprocessing at Sellafield. This means that between 250 and 500 kilograms of plutonium from Sellafield is now adsorbed on sediments on the bed of the Irish Sea. The migration of undersea deposits of actinides to coastal environments represents a long-term hazard of largely unknown proportions.
Technetium 99 (half-life 214,000 years) discharges have led to particular concern. In 1997, technetium concentrations in crustacean particularly in lobster reached 13 times the European Council Food Intervention Level (CFIL) in the vicinity of Sellafield. Some technetium concentrations above CFIL limits have also been found in molluscs (winkles, mussels, limpets and whelks). Recent environmental surveys along the Norwegian coast indicate a six-fold increase in technetium concentrations in seaweed since 1996. Concentration factors are greater than 1,000 for some biota such as macrophytic brown algae, worms and lobsters and are particularly high for some seaweeds (around 100,000). In 1999, a number of high concentrations of various radionuclides were also recorded in fish, shellfish, sediments and aquatic plants, some exceeding CFILs several times. Large uncertainties remain in the field of transfer of technetium in the biosphere.
åð Conclusions on Radionuclide Concentrations in the Sellafield Environment
Marine discharges at Sellafield have led to significant concentrations of radionuclides in foodstuffs, sediments and biota. Discharges lead to current concentrations in some foodstuffs, which exceed European Community Food Intervention Levels (CFILs). The transfer of technetium to the biosphere is of particular concern, because of its long half-life (214,000 years), its mobility in seawater and the high concentration factors in plants. Large uncertainties remain as to the transfer mechanisms and environmental fates of many radionuclides.
During the 1970s and 1980s, peak doses to critical groups in the Sellafield region possibly reached 2.5 to 3.0 mSv per year (as compared to a dose constraint of 0.3 mSv in the UK and 1 mSv in the EU). Latterly, doses to marine-related critical groups have declined to about 0.2 mSv per year.
A recent study commissioned by the German Federal Office for Radiation Protection, using German statutory dose assessment assumptions, calculated that annual doses from consumption of contaminated foodstuffs were more than 5 times the annual limit imposed by the European legislation and about 20 times the annual dose constraint used in the UK and Germany. Most of the dose was received via the technetium contaminated seaweed fertiliser/animal feed/meat consumption pathway. The conclusion of the German study was that the Sellafield reprocessing facilities would not be licensable in Germany. European legislation does not prescribe specific assumptions in dose assessment models. The European Commission has responded that the guidance currently being produced on realistic dose assessments will comment on this issue.
åð Conclusions on Doses Induced by Sellafield Discharges
Discharges to the Sellafield marine environment have led in the past to doses to critical groups exceeding 10 times current UK and 3 times EU limits. The doses calculated by the UK administration from current environmental radionuclide concentrations reach respectively 2/3 and 1/5 of the UK and EU limits. These doses remain problematic, considering that doses from past discharges and from direct radiation are not included. Doses calculated under German statutory dose assessment assumptions exceed UK and EU dose constraints. In addition, German dose limits for organs (also used in the US but not in the rest of the EU) would also be exceeded by the ingestion of relatively small quantities of seafood from Sellafield. The Sellafield reprocessing plants would not be licensable in Germany. Also very large uncertainties in dose estimates remain, with differences between 5th and 95th percentiles often exceeding several orders of magnitude. This raises the question of whether realistic assessments should be used rather than conservative dose assessments.
The risk potential of certain hazards at Sellafield is very large. Liquid high level wastes currently stored at Sellafield contains about 7 million TBq (2,100 kg) of caesium-137, which is about 80 times the amount released through the 1986 Chernobyl accident. Assuming a 50 percent release of caesium-137 in an accident at Sellafield, population dose commitment would range up to tens of millions of person-Sv resulting in over a million fatal cancer cases.
åð Conclusions on Hazards Posed by Liquid High Level Waste at Sellafield
The hazard potential of liquid high level wastes in particular is very high. A serious accident might lead to large releases of radioactivity and on the long term globally to over one million fatal cancer cases.
Higher incidences of childhood leukaemia than expected were first identified near Sellafield in 1983. The cause or causes of the observed increases in childhood leukaemia near Sellafield have not been determined, nor is it known whether a combination of factors is involved. The UK Committee on the Medical Aspects of Radiation in the Environment (COMARE) has stated: As exposure to radiation is one of these factors, the possibility cannot be excluded that unidentified pathways or mechanisms involving environmental radiation are implicated.
Various hypotheses, including paternal preconception irradiation and population mixing have been advanced without being conclusive. Possible explanations for the discrepancy between observed cancers and estimated low doses include erroneous dose assessments (in particular foetal doses) and uncertainties as to the parameter of dose and what it measures.
Besides childhood leukaemia, other areas of concern have arisen, including reports of increased incidence of retinoblastoma in children and a statistically significant increase in stillbirth risk in the Sellafield region.
åð Conclusions on Health Effects from Reprocessing at Sellafield
More than fifteen years of research has established that the excess incidence of childhood leukaemia around Sellafield is statistically significant and is continuing. The cause or combination of causes of the observed leukaemia increases are not known. Many uncertainties remain. Radiation exposure due to radionuclide releases from Sellafield cannot be excluded as a cause for the observed health effects.
6. Case Study La Hague
Between 1966 and the end of 2000, about 21,000 tonnes of spent fuel have been reprocessed at La Hague. Most waste generated at La Hague has remained unconditioned in other words they were not stabilised and packaged for long term or permanent storage for many years, and some is stored under very unsatisfactory safety conditions, including over 9,000 m3 (or 39,000 containers equivalent) of plutonium contaminated sludge.
In 1999, the total radioactivity released by La Hague to the environment was 15,000 times higher than that released by a nearby nuclear reactor. While releases of some radionuclides (e.g. technetium 99, plutonium) have decreased or remained constant, releases of other radionuclides from La Hague have significantly increased over the past decade. These include liquid discharges (iodine 129 x 5; tritium x 3) as well as gaseous releases (carbon 14 x 8; krypton 85 x 5; tritium x 3). Also, some important radionuclides are not measured at all, including chlorine 36, technetium 99, and strontium 90 aerial emissions.
åð Conclusions on La Hague Releases
Releases of radioactivity from La Hague to the environment are several orders of magnitude larger than releases from a nuclear reactor. Releases of some radionuclides have decreased in the past while liquid and gaseous discharges of other key radionuclides have increased significantly. A further group of radionuclides is not being measured in effluents. Increases of radioactive releases from La Hague in the 1990s and expected future discharges are in violation of obligations under the OSPAR Convention.
There have been numerous accidents at La Hague, some involving significant radioactive releases. For example, as a consequence of a severe discharge pipe break in 1980, doses to individuals of the critical group (fishermen) exceeded the annual EU limit of 1 mSv by 3.5 times. Main potential hazards at La Hague are linked to the risk of fires and explosions in the storage pools, in the vitrification plants or in the effluent treatment plants, and to the risk of dispersion of the caesium-137 stocks in the spent fuel pools, or of the separated plutonium stocks.
åð Conclusions on Accidental Releases from La Hague
Past accidents at La Hague include at least one accident that led to population doses significantly exceeding EU limits. Accidents are estimated to be responsible of 36% of the leukaemia risk level for the 0-24 year age category around the La Hague site. The hazard potential of the La Hague spent fuel stores is very large. The accidental release of a fraction of the caesium inventory in the cooling pools could cause up to 1,5 million fatal cancers.
Concentrations of most of the nuclides measured in samples taken in the La Hague environment reached their peak during the 1980s. Nuclide concentrations have decreased on average unequally, depending on nuclides and samples, by factors between 5 and 50 if compared to 1997 levels. These developments do not reflect the large increases in releases of some radionuclides (in particular tritium, iodine 129 and carbon 14). However, there is a notable lack of complete series of data and redundant measurements. Occasionally, there have been samples taken that exceed EU Community Food Intervention Levels (CFILs), in particular in crabs. While most of the samples are taken and measured by operators, it is remarkable that the highest readings were obtained by independent measurements.
åð Conclusions on Radionuclide Concentrations in the La Hague Environment
Radionuclide concentrations in the La Hague environment have generally decreased since the 1980s. However, a comprehensive trend analysis is difficult or impossible because of lacking data on some key radionuclides. The sampling and analysis should be significantly extended in order to guarantee redundancy and a thorough analysis of the impact of the large increases in releases of some radionuclides during the 1990s.
Calculated doses from routine radionuclide releases of the La Hague reprocessing plant generally remain small and well within the EU limits. However, the uptake of radioactivity taken into account in critical group scenarios is very small and can be reached with very small amounts of higher contaminated foodstuffs. Doses can increase accordingly through the consumption of such foodstuffs. The cumulative effective doses induced by the consumption of seafood, as calculated under German statutory dose assessment assumptions, significantly exceed German and EU dose constraints. It is questionable whether the current French practice of dose assessment can be considered conservative.
åð Conclusions on Doses Induced by La Hague Discharges
Calculated doses from routine releases at La Hague generally remain well within EU limits. However, doses calculated under German statutory dose assessment assumptions exceed German and EU dose constraints. The La Hague reprocessing plants would not be licensable in Germany. The current French dose assessment practices do not appear to be conservative.
In 1983, morbidity was found to be higher than expected in the greater La Hague area for men in case of leukaemia and respiratory organs, and for women in case of leukaemia and lung cancer. Moreover, mortality data show an increased rate of cancers for the digestive organs in the Department. In 1995, a study identified an excess of leukaemia cases among persons aged 0-24 years living in the canton about 10 km from the La Hague plant. In 1997 case control study, the authors claimed convincing evidence for a causal role in childhood leukaemia for environmental radiation exposure from recreational activity on beaches and fish and shellfish consumption.
In 1999, the GRNC (Groupe Radio-écologique Nord-Cotentin) reported that the contribution to doses from nuclear facilities was low, as regards the increased incidence of leukaemia revealed in earlier epidemiological studies. While GRNC calculated individual doses up to six times higher than the operator values, these did not exceed 6% of the EU annual limit. The report stated that the result was an average estimate and that uncertainty margins were not quantified. The quantification of these uncertainties is currently underway.
In June 2001, a new study confirmed earlier findings on leukaemia in the La Hague region. The study indicated that the increased incidence was continuing, and provided more data to allow statistical significance to be established for the increases in leukaemia in the La Hague area.
åð Conclusion on Health Effects around La Hague
A statistically significant increase in the incidence of leukaemia in the La Hague area has been established. This increase is continuing. There is, as yet, no conclusive evidence for a causal link to radioactive releases from La Hague. However, these cannot be ruled out as a factor contributing to the health effects observed.
The assessment of doses and their effects are surrounded by many uncertainties. These include errors in assumptions on parameters, errors in computer codes, measurement errors and paucity of environmental monitoring. GRNC has identified more than 4,000 parameters, including 200 critical parameters, in its methodology to assess dose impact.
On the question of iodine 129 releases, WISE-Paris has quantified the differences between the theoretical activity in spent fuel and the activity discharged to sea and air. Large gaps are observed in the beginning of the 1990s, as only 50% of the theoretical values were reported discharged. In the worst case, the committed collective dose from non-attributed iodine 129 in the period 1989-1999 would be about the magnitude of a serious nuclear accident such as the Windscale fire (Sellafield) or the Kyshtym (Russia) waste explosion in 1957.
The Precautionary Principle is clearly laid down in various binding international agreements (e.g. Agenda 21, EC Treaty). In 1992, Agenda 21 pointed out that radioactive wastes are among the contaminants that pose the greatest threat to the marine environment. The Earth Charter of March 2000 calls notably to place the burden of proof on those who argue that a proposed activity will not cause significant harm, and make the responsible parties liable for environmental harm.
åð Conclusions on Uncertainties and the Precautionary Principle
Many uncertainties remain regarding dose assessments. In addition, error margins may be large and might modify assessed doses significantly. Under these conditions, the continued release of large quantities of radionuclides into the environment from Sellafield and La Hague violates the Precautionary Principle.
7. Comparative and Cumulative Analysis
Differences exist in effluent treatment between Sellafield and La Hague. Carbon 14 which is the major contributor to collective doses, for example, is partially removed from air emissions at Sellafield while all of it is released at La Hague. Its abatement is not considered cost effective by Cogema.
In 1999, a representative year, releases from La Hague and Sellafield were broadly comparable. In general terms, La Hague discharges were marginally greater than those from Sellafield, except for iodine 129 and tritium air emissions and technetium 99 liquid discharges.
Until 1992, Sellafield and La Hague released a total of some 1.2 tonnes of iodine 129 to the environment. This is several hundred times that released at Chernobyl. In the period 1993-1998, a further 1.7 tonnes of iodine 129 were discharged (of which 80% from La Hague). Iodine 129 discharged from La Hague and Sellafield in 1999 alone was eight times greater than that released by the fallout from all nuclear weapons testing.
åð Conclusions on Comparative and Cumulative Analysis
In 1999, radioactive releases to the environment from La Hague and Sellafield were broadly comparable. Iodine 129 discharged from La Hague and Sellafield that year was eight times greater than the total iodine 129 released by the fallout from all nuclear weapons testing.
The estimated global collective dose of a decade of radioactive releases from Sellafield and La Hague (77,000 manSv) corresponds to about 1/7 of the collective dose from the Chernobyl accident, or to a Kyshtym scale accident every year. This raises the question of the justification of these releases as required under the radiological principles of the International Commission on Radiological Protection.
Also, in conventional cost-benefit studies, monetary values are attributed to a human life. When applied to untruncated global doses from 10 years of Sellafield and La Hague releases, very large sums are obtained (£ 1.8 and 5.9 billion respectively 2.9 and 9.4 billion Euro): the amounts that therefore could be spent on abatement measures comfortably exceed annual operating profits at each site.
8. Alternative Options
åð Conclusions on Alternative Options
Non-reprocessing options, and available dry storage technologies in particular, are considerably less expensive than reprocessing. In addition, their social and political acceptability are much greater than reprocessing. Nuclear utilities are increasingly moving towards dry storage solutions, including utilities in the US, Canada, Germany, Russia and many eastern European countries. Direct disposal options also significantly reduce waste volumes to be disposed, due to the large volumes generated by reprocessing.
General Conclusions
The reprocessing of spent nuclear fuel at Sellafield (UK) and at La Hague (France) leads to the largest man-made releases of radioactivity into the environment worldwide. The releases correspond to a large-scale nuclear accident every year. Some of the radionuclides released in great quantities have half-lives of millions of years. Concentrations identified in recent years in the environment repeatedly exceeded EU Community Food Intervention Levels (CFILs).
The discharge trends through the 1990s towards large increases in the releases of certain key radionuclides at Sellafield and La Hague and further planned increases in releases constitute a violation of letter and spirit of the OSPAR Convention.
Accidental radionuclide releases from Sellafield and La Hague could be by two orders of magnitude larger than in the case of the Chernobyl disaster and could lead globally over the long term in both cases to over one million fatal cancers.
The European Commission does not effectively use its verification rights. The Commission is highly dependent on information provided by Member States and is therefore apparently not in a position to guarantee that the Basic Safety Standards are respected concerning the La Hague and Sellafield facilities. It is doubtful whether the Commission is in a position to determine whether the reprocessing activities are liable to result in the radioactive contamination of the water, soil or airspace of another Member State.
Operational and/or accidental releases from Sellafield and La Hague have led in the past to population doses that exceed current EU limits. Reprocessing alone accounts for about 80% of the collective dose impact of the French nuclear industry. In the UK, about 90% of nuclide emissions and discharges from the UK nuclear programme result from reprocessing activities.
In the surrounding regions of Sellafield and La Hague a statistically significant increase in the incidence of leukaemia has been established. While research on the causal relationship with environmental radiation has not been conclusive, it cannot be ruled out that exposure to radiation is an initiating or at least a contributing factor.
There are great uncertainties involved in the assessment of doses to populations and subsequent health effects. The release of large quantities of long lived radionuclides at Sellafield and La Hague therefore violates the Precautionary Principle, laid down, inter alia, in the European legislation, Agenda 21 and the Earth Charter of March 2000.
Introduction
Objective of the Study
The principal aim of this report is to assist the Committee of Petitions of the European Parliament in its consideration of Petition 393/95 brought by Dr. W. Nachtwey. The Petition expresses concerns about radioactive discharges from nuclear reprocessing plants at Sellafield in the UK and La Hague in France, and their possible adverse health effects (see summary of the Petition at Annex 1).
The reprocessing of spent nuclear fuel involves its dissolution and the chemical separation of uranium and plutonium. As spent fuel remains extremely radioactive and, as many radioactive waste streams are created by these chemical processes, reprocessing results in significant radioactive releases to atmosphere and sea.
The original rationale for reprocessing was the recovery of fissile plutonium for nuclear weapons. This has declined and officially is no longer a reason for continued reprocessing in the UK and France. Other rationales, including recovery of plutonium for breeder reactors and mixed oxide fuel, have declined or remained static in recent years. As a result, the frequency of new reprocessing contracts is declining. In world terms, most (>80%) spent fuel arisings are stored rather than reprocessed: new developments concern storage rather than reprocessing technologies.
The nuclear fuel cycle involves a number of steps from uranium mining and milling, through enrichment, fuel fabrication, reactor operations, spent fuel storage, radioactive waste conditioning and final disposal. Some nuclear operators have chosen to reprocess rather than store and condition their spent fuel. The single step of reprocessing emits considerably more radioactive discharges than all other steps combined. Reprocessing discharges from Sellafield and La Hague rank among the largest anthropogenic discharges of radioactivity throughout the world, and constitute a reasonable subject for enquiry by the Committee.
Controversy exists over the reprocessing of spent nuclear fuel: views are polarised and strongly held by proponents and opponents. The Governments of Member States UK and France continue to support reprocessing activities in their countries, despite declining public enthusiasm according to opinion polls in the UK, and despite protests from other Member States. In recent years, doubts over waning rationales for reprocessing have been raised by some government and industry officials and by politicians of various political parties, even in the UK and France. The Committee will be aware that continued reprocessing within the European Union is, to a major extent, a political rather than scientific matter.
As requested by STOA, this report concentrates on the effects of reprocessing discharges on health, safety and the environment. In particular, this report presents evidence and data on :
radioactive discharges from the Sellafield and La Hague sites;
resulting nuclide concentrations in environmental media including foodstuffs;
radiation doses from nuclide discharges to critical groups near the sites;
adverse health effects near the two sites; and
resulting collective doses from nuclide discharges.
The report examines a number of current issues in radiobiology concerning health effects from exposure to ionising radiation, in particular genetic and in utero effects.
In addition, in accordance with contract specifications, the report examines other major factors that might influence future decision-making on reprocessing. It describes the legal framework, the operational history of the plants and the economic case for reprocessing compared with available spent fuel management alternatives. The report does not examine mixed oxide fuel (MOX) matters in detail, as these would require a separate study.
The report also makes a number of conclusions and policy-related recommendations that take into account the current knowledge and uncertainties on risk issues and of the availability of alternatives to reprocessing in spent fuel management.
Background and Chronology of the Project
Petition n° 393/95 was introduced by Dr. W. Nachtwey and a group of 22 senior citizens from Hamburg, Germany, in February 1995. The petitioners raised concerns over the radioactive pollution of the North Sea and the Atlantic Ocean due to the operation of nuclear reprocessing facilities at Sellafield (UK) and La Hague (France). The present study project, as requested by the Committee of Petitions, was included in the Year 2000 Work Plan adopted by the STOA Panel on 17 February 2000. It was subsequently approved by the Bureau of the European Parliament on 1 March 2000.
Although Petition n° 393/95 has its origin in an initiative by individuals, it reflects widespread concern in many countries about radioactive discharges and the incidence of radiation-induced illnesses near facilities discharging radioactive matter. For example, concerns over the levels of radioactive contamination from Sellafield and La Hague discharges have been expressed by international and regional bodies, including Agenda 21 and OSPAR meetings.
Within individual countries, the public has also expressed concern about the local impact of reprocessing facilities on environment and health. This has led to initiatives by national authorities to assess corresponding risks, including studies by COMARE (Committee on Medical Aspects of Radiation in the Environment) in the UK, and by GRNC (Groupe Radioécologie Nord-Cotentin) in France. Some Member States (Denmark, Ireland) and countries close to the EU (Norway) have protested for many years over continued reprocessing at Sellafield and La Hague.
Concerns over reprocessing discharges have also resulted in a growing number of studies exploring the risks which may be associated with large-scale nuclide discharges, including raised incidences of childhood leukemias near both reprocessing facilities. So far, no consensus has emerged on whether radioactive discharges have caused the increased incidences of leukemia, even although at least one recent study involved representatives from both industry and environmental groups. Six years after the Petition was introduced, the Petitioners main concerns remain relevant. Therefore the prime objective of this study has been to examine the possible toxic effects from the nuclear reprocessing plants, and derive concrete Policy Options according to the specifications of the contract.
A Scoping Meeting was held in Brussels on 24 January 2001. The co-ordinator of the project presented a Scoping Paper for the study. Only one comment on the Scoping Paper (by the Petitioner) had been received prior to the meeting. A Scoping Meeting Report was delivered on 27 February 2001 that notes that while there was no basic disagreement with the content of the Scoping Paper and the methodology presented by Mr. Schneider on the basis of the contract with STOA, there has been some concern that health and environmental issues will get appropriate attention in the study.
An Interim Report was presented to the STOA Panel on 10 April 2001. The report reflected the current work in progress, and at that stage was felt not satisfyingly balanced between the different parts to be analysed. The co-ordinator of project enlarged the project team in response to the remarks by the STOA Panel and associated two additional experts in the field of radiation effects, Dr. Fairlie and Dr. Sumner, to the team. The focus of the present report reflects the views of the STOA Panel expressed at the earlier meetings.
The Interim Report also contained a set of proposed Policy Options, taking into account the specific roles of major actors in this area. These include the nuclear industry at operational level, the national governments for their key role in decision making on spent fuel management (UK and France but also other Member States), the European Commission, which has powers of supervision and regulation of nuclear activities in the EU, and finally the European Parliament for its legislative and overview roles. The Parliaments roles include the protection of the populations against industrial risks, but also decision-making procedures, public information and participation, independent auditing and decisions on EU institution budgets. The proposed Policy Options were submitted for comments to MEPs and to some experts. The Policy Options presented in this final report take into account comments received.
In the process of the research, the authors have formally consulted, inter alia, the European Commission (DG Environment, Radiation Protection Unit), the French national Institut de Protection et de Sûreté Nucléaire IPSN (the Director of Protection and Chairperson of the Radioecological Group Nord-Cotentin), the DRIRE (Regional Division of Industry, Research & Environment) of the La Hague region. The authors also consulted informally with many other organisations and individuals, particularly in the UK. The co-ordinator wishes to thank all those who contributed to this project.
Reprocessing Status and Issues
Nuclear Reprocessing
The reprocessing of spent nuclear fuel has been carried out since the 1950s in a number of countries to retrieve fissile plutonium, originally for weapons purposes. Reprocessing has been also carried out by a few other countries in small amounts for fuel purposes (e.g. Japan and India). However clearly the largest centres in the world for commercial reprocessing remain Sellafield in the UK and La Hague in France.
The United Nations [UNSCEAR, 2000] has stated that only about 5% to 10% of world spent fuel arisings is submitted to reprocessing: the rest is stored pending final disposal in a repository. The number of countries relying on reprocessing to deal with their spent fuel has been declining [IAEA, 1999].
The reprocessing of spent nuclear fuel involves its dissolution in boiling concentrated nitric acid and subsequent physico-chemical separations of uranium and plutonium. Multiple waste streams are created by these physical and chemical processes. These waste streams include releases from fuel storage ponds, dissolver units, solvent treatment plants, HLW (liquid) processes and tanks, ILW processes and tanks, LLW processes, off-gas treatment plants, and liquid scrubber plants [Homberg, 1997].
As spent fuel contains high levels of radioactivity, discharges from reprocessing are correspondingly radioactive. Most fission product releases and plutonium releases from the UK and French nuclear programmes result from their respective reprocessing activities. It will be seen below that, apart from reductions in discharges of a few radionuclides, discharges and emissions from the two facilities have not decreased over the past few decades and indeed, in the case of some nuclides, have increased.
Reprocessing operations release considerably larger volumes of radioactive discharges than other nuclear activities, typically by factors of several 1,000 compared with nuclear reactor discharges. According to a European Commission report [CEC, 1995] produced by the Centre dÉtude sur lÉvaluation de la Protection dans le domaine Nucléaire (CEPN, a research agency essentially funded by CEA and COGEMA), reprocessing alone accounts for about 80% of the collective dose impact of the French nuclear industry. In the UK, Fairlie [1997] has estimated that about 90% of nuclide emissions and discharges from the UK nuclear programme result from reprocessing activities.
Origins of Reprocessing
Uranium-fuelled reactors produce plutonium in their nuclear fuel during normal operation. The main fissile plutonium isotope, plutonium 239, is produced through neutron capture by the uranium isotope uranium 238. As stated above, the main purpose of reprocessing is to retrieve plutonium from spent fuel. Plutonium is a man-made element, which exists only in trace amounts in nature. In France and the UK, bulk quantities of weapons plutonium were produced in the first generation of nuclear power plants, and separated from spent fuel initially in dedicated reprocessing plants.
Early in the development of nuclear technology, plutonium became of particular interest to the nuclear power industry. The establishment of breeder reactor technology became a major goal. The basic concept was fascinating: plutonium generated as by-product in first-generation, uranium-fuelled nuclear reactors would be separated, incorporated into fuel assemblies, and re-introduced into second-generation breeder reactors that would produce more plutonium than they consumed. In this manner, the lifetime of uranium reserves would be greatly extended. Decision-makers were impressed by this concept, and research & development funds were distributed generously. In fact, the first reactor to produce electricity was the US Experimental Breeder Reactor EBR-1, in 1951.
By the early 1970s, the major nuclear countries had breeder programs under way. France commissioned the 250 MWe Phenix in 1973 and the UK the Prototype Fast Reactor (PFR) in 1974. During the same period, the European 1,200 MWe Superphenix project was launched. In 1977, the head of the French Atomic Energy Commission (CEA) predicted the operation of 540 large breeder reactors in the world by the year 2000.
To supply plutonium for the expected fleet of breeders, the European nuclear establishment launched large-scale reprocessing plant projects in the 1970s. After the first international project, the reprocessing plant EUROCHEMIC in Belgium, failed because national projects received higher priority, utilities chose to have their spent fuel reprocessed in France at La Hague and in the UK at Sellafield. Between 1976 and 1979, following a first series of smaller agreements, contracts were signed for the reprocessing of some 7,000 tonnes of spent fuel at each plant, UP3 and THORP. These reprocessing contracts have been mostly completed between 1990 and 2000. Utilities from EU Member States Belgium, France, Germany, Netherlands, Sweden and the UK, plus Japan and Switzerland, signed up to those contracts.
Two decades later the situation has changed radically. Massive new uranium ore sources have been found much greater than had been expected. Consequently the prices of natural uranium have been falling from one historical low to another. Breeder programs, which proved more expensive and less technically successful than anticipated, have been shelved. Germany abandoned its completed SNR-300 reactor at Kalkar in 1991 before it started up. The plant was turned into an amusement park. The UK shut down its PFR in 1994. The worlds only commercial-size breeder reactor, Superphénix in France, was shut down in 1996 after achieving a lifetime load factor of 6.3% (actual electricity generation as a fraction of the theoretical maximum).
However plutonium production programs were not modified in response to these developments. Large reprocessing plants at Sellafield and La Hague were put into operation between 1989 and 1994 as if nothing had changed. As a result, large stockpiles of plutonium, reprocessed uranium and reprocessing wastes continue to build up in both countries. The impacts of reprocessing should be viewed within a broad context. Reprocessing does not occur in isolation, but as an element of a countrys wider political policies. The social costs and benefits of reprocessing should be analysed accordingly.
In recent years, the plutonium industry put forward MOX fuel (plutonium-uranium mixed oxide fuel) as a rationale for continued reprocessing. These claims, like reprocessing itself, are the subject of conflicting views. This report refrains from examining MOX issues in detail as these lie outside its remit. However it is noteworthy that the maximum anticipated MOX fuel use, i.e. about 200 tonnes per year, is small in comparison with the 11,000 tonnes of uranium fuel used each year.
Also in recent years, proponents of reprocessing have stated that it continues to offer utilities a method of managing their spent fuel stocks. This report discusses the safer and less expensive alternative of medium-term dry storage. However it is noted that, in some cases, decisions by different utilities on spent fuel management differ widely for reasons which appear to have more to do with policy and belief than technical necessity or commercial considerations. These attitudes are often not amenable to rational discussion.
Implications of Reprocessing
Reprocessing is one option among various spent fuel management options. In the year 2000, the volume of spent fuel reprocessed was about a sixth of the spent fuel generated worldwide: most reprocessing occurs at La Hague and Sellafield. As can be seen from this low fraction of spent fuel reprocessed, most utilities operate their nuclear power plants without reprocessing and plutonium use. Therefore this reports examination of reprocessing does not imply any comment on nuclear power programmes.
Differences of view exist between Member States of the European Union on reprocessing. Views on continued reprocessing remain polarised between different groups within Member States, and within European Union bodies. Consequently, nuclear reprocessing remains a highly politicised subject, on which a consensus may be difficult to achieve.
International and European Legal Framework
International Legislation and Treaties
Although the regulation of nuclear energy remains the responsibility of national authorities, the fact that nuclear-related activities have potential transboundary impacts, has brought the international community to take on the elaboration of some common standards. A list of the main texts is presented in the Annex 2.
Major International Bodies
International and regional organisations have played a major role in the development of nuclear standards.
The International Commission on Radiological Protection (ICRP)
International action in the field of radiation protection standards started with the establishing of the International Commission on Radiological Protection (ICRP). The ICRP was founded in 1928 (and reconvened after the II. World War in 1950) by the International Society of Radiology as its commission on international issues. The main committee of the ICRP, 13 members, voted in by co-optation, provides recommendations and guidance on all aspects of the protection against ionising radiation that is turned into a legal framework by most of the countries in this world.
United Nations Committee on the Effects of Atomic Radiation (UNSCEAR)
The United Nations Committee on the Effects of Atomic Radiation (UNSCEAR) was established in 1955 by the United Nations to evaluate doses, effects and risks from ionising radiation on a world wide scale following growing concerns over potential effects from nuclear weapons testing. Most of the standards elaborated by international and regional organisations such as Euratom and the International Atomic Energy Agency (IAEA) are based on the research undertaken by the ICRP and UNSCEAR.
The International Atomic Energy Agency (IAEA)
The United Nations International Atomic Energy Agency, IAEA, is primarily an inter-governmental forum for scientific and technical co-operation (and promotion) in the nuclear area. The IAEA today counts 130 Member States. The Agency provides its Member States with guidance and standards as a complementary element to national criteria and regulations when the latter are not based on other existing international conventions.
OECD Nuclear Energy Agency (NEA)
The Nuclear Energy Agency (NEA) is a semi-autonomous body within the Organisation for Economic Co-operation and Development (OECD). The Agency provides assistance to its Member countries in developing scientific and legal bases for the safe use of nuclear energy. The NEA counts 27 Member States, representing 85% of the world installed nuclear capacity.
Major International Conventions
The international legal framework in the nuclear sector is composed of legally binding agreements and recommendatory standards. Among the most important international conventions on radioactive material management that have contributed to the development of the international legal framework in the nuclear sector one may cite:
The Convention on Nuclear Safety
It entered into force on 24 October 1996. The Convention commits the signatories to ensure the safety of civil nuclear power plants including the storage, handling and treatment of radioactive materials.
The Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management
It was open for signature in September 1997. Within the framework of this agreement, the parties must take the necessary measures to ensure the safe and environmentally sound management of radioactive waste and spent fuel.
A large number of bilateral and multilateral agreements have also dealt with safety standards and regulations in the nuclear sector, particularly in the field of marine pollution.
While major international conventions have referred to the necessity to prevent marine pollution from nuclear activities, for instance Agenda 21 (June 1992) and the Earth Charter (June 2000), others were specifically devoted to this matter, notably:
The Convention on the Prevention of Marine Pollution by Dumping of Wastes and other Matter London Dumping Convention
It was signed on 29 December 1972. Aiming at improving the protection of the marine environment, the Convention encourages States, with a common interest in particular geographical areas, to enter into appropriate agreements to promote the effective control of all sources of pollution. In particular, it prohibits the dumping of wastes if not duly authorised and controlled by the Member States authorities.
The Convention for the Protection of the Marine Environment of the North-East Atlantic OSPAR Convention (see also Chapter 3.2 and Annex 3)
It was opened for signature at the Ministerial Meeting of the Oslo and Paris Commissions in Paris, on 22 September 1992. The Convention has been signed and ratified by all of the Contracting Parties and it entered into force on 25 March 1998. It defines general guiding principles to deal with the problem of pollution, from land-based sources notably (Annex I of the OSPAR Convention), such as the precautionary principle; the polluter pays principle and best available techniques (BAT) and best environmental practice (BEP), including clean technology. It also provides for the OSPAR Commission, established by the Convention, to adopt binding decisions.
The European Legal Framework And Its Implementation
The basis of European law is established in the European Community Treaties. In particular, the majority of legislation dealing with nuclear activities is found in the Euratom Treaty, signed in Rome on 25 March 1957.
In addition to Council Directive 96/29/Euratom, there are a number of other directives and regulations relating to specific activities within this sector, which deal with the different issues, among which:
health and safety at work (Radiation Protection of Outside Workers, Council Directive 90/641/EURATOM);
transport of radioactive substances (Shipments of Radioactive Waste, Council Directive 92/3/EURATOM);
and shipments of Radioactive Substances, Council Regulation (Euratom) No. 1493/93.
The main documents applying are listed in the Annex 4.
Euratom Treaty
The Treaty Establishing the European Atomic Energy Community (Euratom Treaty) lays the foundation for the Community regulation in the nuclear sector. Other relevant legislation can also be found in the EEC Treaty and supplement and the Single European Treaty.
European legislation does not provide for a control of the Member States national procedures leading to the granting of authorisations of releases of radioactivity to the environment.
As a primary legislative instrument, the Euratom Treaty imposes obligations on the Member States under Articles 33 to 37 concerning notably the monitoring of the environment and the disposal of wastes.
Application of Article 34
Article 34 states: Any Member State in whose territories particularly dangerous experiments are to take place shall take additional health and safety measures, on which it shall first obtain the opinion of the Commission. The assent of the Commission shall be required where the effects of such experiments are liable to affect the territories of other Member States.
The Commission declared that: France has not requested the Commissions opinion under Article 34 of the Euratom Treaty concerning activities on La Hague nor has the UK as regards activities in Sellafield. Given the number of previously untested activities carried out at La Hague and Sellafield, it is extremely surprising that there has not been a single request by the operators for opinion under Article 34. In fact, there has never been a single request for a Commission Opinion by the UK (unclear for France). The oral explanation given by the Commission that the original aim of the article was to cover peaceful nuclear explosions that were never carried out in the EU is not satisfying. The legal analysis of the non-application of Article 34 would go beyond the scope of this study but seems to be absolutely indispensable.
Application of Article 35
Article 35 is the strongest legal basis for the implementation of an efficient control mechanism of nuclear installations in the EU. It states: Each Member State shall establish the facilities necessary to carry out continuous monitoring of the level of radioactivity in the air, water and soil and to ensure compliance with the basic standards. The Commission shall have the right of access to such facilities; it may verify their operation and efficiency.
The Basic Safety Standards for the protection of health of the general public and workers against the danger of ionising radiation are laid down in the Directive (80/836) of 15 July 1980. These standards were revised in the Euratom Directive (96/29EURATOM) of 12 May 1996.
European Commission verification activities provided for in Article 35 are very limited due to resource constraints: Since the re-launch of the verification activities in 1990 the Commission has performed verification visits at the Sellafield site on 6-10 December 1993 and at the La Hague site on 22-26 July 1996. Each verification visit is normally performed by 4 inspectors, who carry out checks on the operation of instruments for environmental monitoring and follow the data chain for a number of randomly chosen samples from sampling through to transmission of the final results to the competent authorities. The quality assurance system is also checked. The Article 35 of the Euratom Treaty verification activities are currently being reviewed by the Commission.
The Commission has commented on the issue on a number of occasions in answers to parliamentary questions. One of those answers stated: The installations which were the object of this check are primarily those which have a direct impact on the environmental radioactivity level
The equipment for monitoring gaseous and liquid effluents from these establishments was also checked as part of the assessment of their impact on the environment. Parliament and other Member States are forwarded, on request, the main comments formulated by the Commission. The Council and the Parliament are periodically provided with a report summing up the progress made with its programme of checks.
During a meeting with the Co-ordinator of the present study and in a subsequent letter the Commission has clarified a certain number of points:
The Commission has repeatedly made reference to the re-launch or the resumption of Article 35 verification activities. However, the term is based on oral information about some earlier verification activities that would have been carried out in the 1960s. No written evidence exists within the Commission services to back up that information. The Commission representatives exclude that La Hague military significance or Sellafield the UK joined the EC later were amongst these potential verifications in the 1960s.
In 1990, the Commission planned to carry out about 60 verifications per year. The goal was to inspect each facility in the EU on average about once every five years and major facilities like reprocessing plants every two years. In reality, only two to three verifications have been carried out per year and in total 20 verifications have been carried out in the 10 year period between October 1990 and December 2000. Only two are planned for 2001. The main reason indicated by the Commission are of budgetary nature.
The Commission considers that the conclusions reached at the verifications at Sellafield in 1993 and La Hague in 1996 with respect to arrangements for monitoring environmental radioactivity could be expected to be broadly the same. There have however been developments, particularly at Sellafield (e.g. start of operation of THORP and EARP) that did not operate at the time of the visits. During the meeting in Luxembourg the Commission representatives clearly stated what that means: the verification, particularly at Sellafield but also at La Hague, is out of date.
The Commission stated that although compliance with the requirement to assess and limit doses is a Member State responsibility, the Commission does have a significant amount of information available to it on this matter. These data indicate that, in general, the radiation doses received by the public are a small fraction of the dose limits and that the maximum credible range of uncertainties would not compromise respect of this limit. The Commission is aware of the circumstances under which dose limits to the public might be exceeded and is vigilant in taking a proactive approach to verify compliance.
Member States consider, as stated by Michael Meacher, Minister for the Environment in the UK, that under Article 35 of the Treaty the European Commission has the right of access to certain facilities. The Article does not require submissions to be made to the Commission.
The Commission was not in a position to supply the STOA Study Team with copies of the verification reports on Sellafield and La Hague because they fall under the exemptions to access provided for under the access policy and that there is therefore no entitlement to see them. However, the Commission informed the STOA Study Team that it has asked the UK and France if they would agree to the reports being released to you. As of the end of July 2001, the Study Team had not received any answer on the issue from the Commission.
However, the STOA Study Team in the mean time found out that a copy of the 1993 Sellafield Verification Report had been placed in the Library of the UK House of Commons. The 29 page report (plus tables) is a stunning indication of the superficial nature of the Article 35 verification exercise:
- The preparatory documents referenced were essentially of statistical nature.
- The four person verification team had a huge visiting programme during a three and a half day presence at Sellafield and in the surrounding area, including visits of the BNFL ship Seascan, of a laboratory in Whitehaven, witnessing demonstrations of measurements in the environment and of collection of winkles, visiting a dairy farm, an air sampler at Calderbridge and at least seven stacks besides a conducted tour of the disposal site at Drigg.
- The introduction to the report states that given the complexity of the facilities, the purpose of the review was not to undertake a systematic verification of all of the aspects but to provide an overview of the system with a number of spot checks limited by the time available and while only part of the discharge monitoring facilities could be verified, their selection was representative for the overall surveillance programme, thus allowing to draw general conclusions on its adequacy. However, the report fails to justify the methodology and the representative nature of its verification activities.
- The general conclusion (less than 1 page of text) states that the team observed the proper functioning of a representative subset of stack monitoring equipment and that any controlled ground level aerial releases are properly accounted for and that the overall arrangements ensure that aerial releases and their environmental impact are well controlled and finally that discharges to the sea are adequately monitored.
- The report is of exclusively descriptive nature. It does not contain any analysis, nor any discussion (for example of error margins or technical and conceptional uncertainties), nor any kind of criticism. The verification team obviously found the situation at Sellafield perfect.
The STOA Study Team considers that the Commissions activities carried out under Article 35 are obviously not appropriate to make effective use of its control rights of monitoring facilities and verify their operation and efficiency. Statements by the Commission on the appropriate nature and efficiency of such monitoring facilities at Sellafield and La Hague are not backed up by credible data.
Furthermore, the Commission is apparently highly dependent on information provided by Member States and is therefore apparently not in a position to guarantee that the Basic Safety Standards are respected in the Member States and concerning the La Hague and Sellafield facilities in particular.
Application of Article 37
Since 1979, the Commission has issued three opinions concerning La Hague within the framework of Article 37 of the Euratom Treaty that requires that each Member State shall provide the Commission with such general data relating to any plan for the disposal of radioactive waste in whatever form as will make it possible to determine whether the implementation of such plan is liable to result in the radioactive contamination of the water, soil or airspace of another Member State.
The Commission gives its Opinion after consulting a group of experts. Article 37 is completed by the Commission Recommendation 1999/829/Euratom of 6 December 1999 which defines the data to be transmitted to the Commission and the time limits to be respected.
As an illustration, the Commission Opinion concerning the nuclear fuel reprocessing plants UP3 and UP2800 of the La Hague Establishment was issued according to the following procedure:
On 1 March 1989, reception of the general data concerning the plan for the disposal of radioactive waste transmitted by the French authorities. The general data is not available from the Commission as it is considered confidential with the Member States.
On 8 June 1989, meeting of the Group of Experts set up pursuant to the Treaty, in Cherbourg. The experts required further complementary information.
On 20 July 1989, the Commission concluded in its Opinion on the La Hague facilities that: the implementation of the plan for the disposal of radioactive waste from the UP3 and UP2-800 plants at the La Hague Establishment is not liable, either in normal operation or in the case of an accident of the type and magnitude considered in the general data, to result in radioactive contamination, significant from the point of view of health, of the water, soil or airspace of another Member State; however, in certain severe accidental circumstances, significant levels of contamination might be obtained in the Channel Islands, but the projected doses could be reduced at non-significant levels by the introduction of countermeasures.
The selection of reference accidents is made by the national authorities and it is not in the intention of the Commission or the experts to impose specific reference accidents. Nevertheless, it is the responsibility of the Commission and the experts to consider if the accidents taken into consideration are those which are of importance for the type of installation concerned, as regard the frequency and the potential for major release.
The loss of cooling to a High Active Liquor feed vessel was considered as a reference accident in the case of Sellafield. As regards the La Hague (UP3 and UP2-800) submission, the reference accident taken into consideration was the loss of cooling in the concentrated fission products vessels.
At Commission level, the estimated number of man-months spent to analyse the General Data and to draft the Report of the Group of Experts and the Commissions Opinion is about 2 for reprocessing. The Commission managed to present its Opinion in less than five months after the submission of the General Data by France. Considering the difficulty in co-ordinating a Group of Experts of over 40 people, not to speak about the time necessary to countercheck a significant amount of complex data and review additional input from the experts, two man-months over four and a half month period seems a very small time budget.
It is highly questionable whether the Commission under these conditions is in a position to fulfil its obligation under Article 37 to determine whether the implementation of such plan is liable to result in the radioactive contamination of the water, soil or airspace of another Member State. The Opinion expressed by the Commission appears to excessively rely on the General Data submitted by the Member States. This reliance is not being adequately expressed in the various generally re-assuring statements made by the Commission on the impact of the facilities at Sellafield and La Hague.
Marine Pollution - Application of the Precautionary Principle
While the marine environment is sometimes treated as convenient sink, or even as interesting laboratory (see Annex 5), international conventions have repeatedly justified the application of the precautionary principle, especially for discharges of radioactive effluents into the sea, as a means to respond to uncertainty.
In 1992, Agenda 21 put forward the characteristics of radioactive wastes to call for a safe and environmentally sound management, including their minimisation, transportation and disposal (Chapter 22). It clearly pointed out that radioactive wastes are among the contaminants that pose the greatest threat to the marine environment.
The signatories were called upon to support efforts within IAEA to develop and promulgate radioactive waste safety standards or guidelines and codes of practice as an internationally accepted basis for the safe and environmentally sound management and disposal of radioactive wastes (Chapter 22).
Highlighting the fact that there was no global scheme to address marine pollution from land-based sources, Agenda 21 called on nations to commit themselves to control and reduce degradation of the marine environment to maintain and improve its life-support and productive capacities, the aim being to anticipate and prevent further degradation of the marine environment and reduce the risk of long-term or irreversible effects on the oceans (Chapter 17).
In its Section II. Ecological Integrity, Paragraph 6, the Earth Charter of March 2000 called on nations to Prevent harm as the best method of environmental protection and, when knowledge is limited, apply a precautionary approach:
a. Take action to avoid the possibility of serious or irreversible environmental harm even when scientific knowledge is incomplete or inconclusive.
b. Place the burden of proof on those who argue that a proposed activity will not cause significant harm, and make the responsible parties liable for environmental harm.
c. Ensure that decision making addresses the cumulative, long-term, indirect, long distance, and global consequences of human activities.
d. Prevent pollution of any part of the environment and allow no build-up of radioactive, toxic, or other hazardous substances.
e. Avoid military activities damaging to the environment.
The London Dumping Convention of 1972, in which the signatories convened to promote the effective control of all sources of pollution of the marine environment (Article 1), gave an impulse to international co-operation some twenty years later with the conclusion of the OSPAR Convention. The latter considered that additional international actions aiming at preventing and avoiding marine pollution had to be taken as part of a progressive and coherent program for the protection of the sea.
The OSPAR Convention required the application of the precautionary principle by taking every possible measure to prevent and eliminate pollution and protect the maritime zone against prejudicial effects of human activities (Article 2). The French authorities, nevertheless, consider that the OSPAR Convention defines only general obligations, such as the prevention and elimination of pollution with the application of the precautionary and the polluter-pays principles notably. Further detailed decisions taken within the framework of the OSPAR Convention commit only the Member States which voted them. There is a risk that such decisions remain unapplied as long as they are not signed by France and Great Britain.
In 1999, the OSPAR Commision defined the following strategy regarding radioactive substances :
-by the year 2000
a. the Commission will, for the whole maritime area, work towards achieving further substantial reductions or elimination of discharges, emissions and losses of radioactive substances;
-by the year 2020
b. the Commission will ensure that discharges, emissions and losses of radioactive substances are reduced to levels where the additional concentrations in the marine environment above historic levels, resulting from such discharges, emissions and losses, are close to zero.
The decision adopted in June 2000 (and which came into force in January 2001) concerning discharges in relation with reprocessing compels the signatories to review as a matter of priority the authorisations for radioactive discharges from reprocessing plants, and work towards implementing the non-reprocessing option. The United Kingdom and France, although they refused to sign the decision, are politically obliged to comply with the orientation defined by the Commission. Similarly, the Sintra Declaration signed in July 1998, calling for near zero-level discharges of liquid radioactive substances by the year 2020, is much more a plea for a common political will to protect the environment than a legally-binding instrument.
The matter therefore should clearly be addressed at European level in application of Article 174(2) of the EC Treaty: Community policy on the environment shall be (
) based on the precautionary principle and on the principles that preventive action should be taken, that environmental damage should as a priority be rectified at source and that the polluter should pay.
Risk Assessment of Radioactive releases
Releases from Reprocessing
Nuclide releases from reprocessing depend on the tonnages, types, enrichments, storage periods and burn-ups of fuels, which are reprocessed. Nuclear inventories in spent fuel are estimated by computer codes that analyse nuclide concentrations from fission rates and neutron fluxes in reactors. Most codes are derived from US programs for light water reactors, such as ORIGEN or its derivatives.
Nuclide emissions to air from nuclear facilities are transported in radioactive plumes, which deposit particulates and aerosols downwind. This results in contamination of local food chains, including the grass-cow-milk-infant chain. In addition to doses from the ingestion of contaminated local foods, local individuals may also receive radiation doses from immersion in radioactive aerosols, inhalation of radioactive gases and particulate matter, and ground shine from nuclides deposited on land. From nuclides discharged to sea, individuals may receive doses from ingestion of fish, crustaceans and molluscs. The use of contaminated seaweed as animal feed and as fertiliser, the return of nuclides via sea spray and foam are additional marine contamination pathways.
Various computer models have been designed to estimate radiation doses to members of critical groups living near nuclear facilities from nuclide releases. These groups are expected to receive the highest levels of radiation: limits are designed to protect these individuals on the theory that if these people are protected, all other individuals in the population will also be protected. As discussed below, these critical group limits only protect individuals and not populations.
Collective Doses
Introduction
Radiological impacts of nuclide discharges are conventionally measured in two ways. First, by estimating the average individual dose to members of critical groups near nuclear facilities; second, by estimating doses to whole populations affected by nuclide discharges. The latter are usually termed collective doses. The main advantage of collective dose is that, were only individual dose used, the dilute and disperse approach to waste management might be encouraged rather than the retain and concentrate approach preferred by some Member States [see DETR, 2000].
Differences of view exist within radiation protection circles over the usefulness of collective dose. On the one hand, international agencies and some national authorities use and recommend the use of collective doses. For example, the European Commission has implemented a Directive (Euratom 96/29) containing detailed procedural requirements on collective dose, as described in Annex 6. On the other hand, despite legal requirements and authoritative recommendations, there remains a reluctance within the nuclear industry and some national regulatory agencies to embrace collective dose. Although rarely discussed in the open literature, unco-operative attitudes towards the use of collective doses remain in some quarters.
Theoretical Justification
The crucial theoretical underpinning for collective dose lies in the adoption by the scientific community of the Linear No-Threshold (LNT) model for radiations adverse health effects [ICRP, 1991; NCRP, 1995]. This model states that there is no level of radiation exposure below which there is no effect: risks continue with declining doses until zero dose. Even the smallest possible dose, i.e. a photon passing through a cell nucleus, carries with it a risk of cancer. Although this is an extremely small risk, it is still a finite risk. The LNT relationship is important for collective dose, as most individual doses in a collective dose are extremely small. The LNT model justifies the estimation of these extremely small doses, and justifies their addition to produce collective doses. More detailed information on the use and calculation of collective doses is contained in Annex 6.
Global Collective Doses
Global collective doses arise from the discharge of certain nuclides with long half-lives, including tritium, carbon 14, chlorine 36, krypton 85 and 1291, which are globally distributed and act as long-term low-level sources of radiation exposure to the worlds population. Recent high discharge levels of technetium 99 have prompted consideration of its likely global distribution [Fairlie and Sumner, 2001]. Global compartmental models estimating global doses from releases of several nuclides have been constructed by the IAEA [1985], and the European Commission [Simmonds et al, 1996] and [Titley et al, 1995].
Important Radionuclides in Reprocessing Releases
Radiation doses depend strongly on the individual radionuclides to which the public is exposed. Therefore a brief description of the main nuclides discharged from reprocessing facilities is set out below.
Carbon-14 (14C)
Carbon 14 is a radioactive isotope of carbon with a half-life of 5,730 years: it emits beta particles of maximum energy 156 keV. The major sources of carbon 14 in irradiated nuclear fuel are neutron activation of nitrogen (in fuel as impurity and/or additive) and oxygen (in fuel as UO2). carbon 14 is retained in spent fuel until reprocessing when it is released in both gaseous and liquid forms.
Carbon 14 is produced naturally in the upper atmosphere as a result of the capture of cosmic ray neutrons by nitrogen 14. Because carbon 14 behaves in the same way as stable carbon, it is rapidly distributed among environmental compartments stratosphere, troposphere, biosphere and surface ocean waters. Transfers between atmosphere, biosphere and surface ocean waters take place with time constants of a few years; transfer to deep ocean proceeds more slowly.
Carbon is a major constituent of all life forms. All carbon 14, whether anthropogenic or naturally-occurring enters the natural carbon pool including all biota. Because the half-life of carbon 14 is 5,730 years, doses from carbon 14 introduced into the environment will be delivered to local, regional and global populations for many generations. carbon 14 is the main (>80%) contributor to collective doses from reprocessing discharges, as discussed in Chapter 7. Carbon 14 collective doses are similar whether released to atmosphere or sea.
Krypton-85 (85Kr)
Krypton 85 is a strong beta-gamma emitter with a half-life of 10.7 years. It is a fission product retained in reactor fuel until released during reprocessing. Krypton 85 released to atmosphere exposes people to external beta irradiation of the skin, and to uniform whole body gamma irradiation. Although the dose from a single decay of krypton 85 is small, the amounts of krypton 85 discharged are very large the largest of all nuclides emitted by reprocessing. Accordingly doses from krypton 85 are appreciable. Krypton 85 distributes uniformly throughout the earths atmosphere within a few years after release, so collective doses from krypton 85 are important.
Krypton 85 is an inert gas and is currently not thought to enter life processes nor be incorporated in biota, unlike iodine 129, carbon 14 and tritium. Krypton 85 dosimetry is based on theoretical models rather than experimental data. The little data which exists refer to acute, non-equilibrium exposures: it is difficult to estimate long-term doses reliably from such information.
Iodine-129 (129I)
Iodine 129 is a weak beta emitter with a half-life of 16 million years. It is produced during the fission of uranium with a yield of 1% and is released during reprocessing in large quantities. Its long half-life means it will widely distribute in the environment, become part of the iodine pool, and deliver a thyroid dose to the global population. Iodine is mobile in the environment, and rapidly incorporated in foodstuffs. The highest environmental concentrations of iodine occur in seawater.
Considerable uncertainty surrounds the transfer of iodine 129 to deep oceans and the sedimentation processes that may remove activity from biological chains [UNSCEAR, 1988]. The observed residence time of iodine in the ocean is about 100,000 years [Raisbeck, 1995]
The estimation of radiation doses from all environmental radionuclides is carried out by models of varying complexity. Their results should be validated by comparison with environment measurements.
The lack of monitoring and model validation for iodine 129 releases from La Hague has been criticised by CRII-Rad [1997]. Their report drew attention to iodine 129 measurements one or two orders of magnitude higher than those predicted by the MARINA model. It stated that these under-estimations were probably due to incorrect iodine concentration factors.
CRII-Rad also pointed out that the estimation of doses to individuals did not take into account use of seaweed in industrial applications (e.g. extraction of polysaccharides from Chondrus crispus for use in ice cream, desserts etc.), and use of seaweed as an agricultural fertiliser. Iodine in seaweed can be transferred to vegetables with very high transfer factors; for maize the concentration factor is 3. Raised iodine 129 levels in seaweed is not just local to La Hague, but occurs on the French coast from North Brittany to the Pas-de-Calais, and to a lesser extent on the south coast of England and on North Sea coasts.
The release of iodine 129 to atmosphere is an important component of dose to the terrestrial (i.e. land) critical group. Predicting iodine 129 concentrations in milk is a difficult and uncertain process: widely different values of iodine 129 dose have been estimated around the Sellafield plant [Fulker et al, 1997a].
Problems with iodine 129 dosimetry include:
Uncertainties concerning the chemical and physical forms of iodine, i.e. the proportions of organic, inorganic and particulates iodine.
Iodine 129 is difficult to measure at the concentrations encountered in the environment
Some parameters in iodine models are very uncertain, including the grass to milk parameter [Fulker et al, 1997a, 1997b] .
Recently it has become possible to measure iodine 129 using neutron activation analysis, which has a lower limit of detection. The Groupe Radioécologique Nord Cotentin, chaired by Dr. Annie Sugier, Director of Protection at the French National Institut de Protection et de Sûreté Nucléaire (IPSN) has highlighted [GRNC, 1999] the significant difference between calculated and measured quantities of iodine 129 discharged into the environment. However, the Group did not analyse possible reasons for this nor potential impacts of the problem. It has been shown (see Annex 25) that considerable differences exist between estimated iodine 129 inventories in fuels processed and actual iodine 129 releases: up to 50% of the theoretical activity could not be accounted (see Chapter 6 on La Hague).
Tritium (3H)
Tritium (3H) is the radioactive isotope of hydrogen. It is a weak beta emitter with a maximum decay energy of 18 MeV, and a half-life of 12.3 years. Tritium is formed naturally through cosmic ray interaction with H in the upper atmosphere. However, anthropogenic tritium emissions considerably exceed natural sources. Tritium commonly occurs as tritiated water, i.e. 3HOH, and as elemental tritium gas, 3HH. Tritium is created in nuclear fuel by the activation of hydrogen (1H) and deuterium (2H), and as a tertiary fission product. Some tritium is released at reactors but the majority is released from reprocessing plants at fuel dissolution stage.
In some respects, tritium is an unusual radionuclide. The high mobility of tritiated water in the biosphere, cycling in the biosphere, multiple pathways to man, ability to bind with cell constituents to form Organically Bound Tritium, and the heterogeneous dose distribution of bound tritium mark it out, potentially, as a hazardous radionuclide. These characteristics are not reflected in tritiums safety limits that are based on its dose per unit intake, which is relatively low. In sum, tritium is a very efficient distributor of radioactivity in the environment and in the human body [Fairlie, 1992].
Ingested tritiated water has a biological half-life of about 10 days. Ingested tritiated foodstuffs (OBT) have much longer half-lives, which are poorly defined and may extend to several years in some tissues.
Technetium-99 (99Tc)
Technetium 99 is a radioactive isotope of technetium, which emits beta particles and has a half-life of 214,000 years. It is produced at relatively high yield in the fission of uranium.
Technetium does not occur naturally in the environment. Globally, the dominant sources of technetium 99 are fallout from nuclear weapons testing in the atmosphere, releases from nuclear fuel reprocessing and the use of 99mTc (which decays into 99Tc) in diagnostic nuclear medicine [Smith et al, 1997]. Technetium is present in the marine environment mainly in the form of the pertechnetate ion (TcO4-), which is soluble and may be transported over long distances.
In the human body, the pertechnetate ion behaves in a similar way to the iodide ion, i.e. it concentrates in the thyroid (although unlike iodide it is not incorporated into hormones). Hardly anything is known however, about the possible existence of other chemical forms, and their stability and environmental pathways.
Because technetium 99 is soluble and unbound to sediments, it travels rapidly from its point of release. From Sellafield, the transit time to the North Channel (between Northern Ireland and South West Scotland) is about 3 months, to the Northern North Sea 6 months and the Norwegian Coastal Current around 2.5 years [Leonard et al, 1997].
Uncertainties in Risk Assessment
There are two main ways to assess potential environmental and health impacts associated with reprocessing discharges:
direct measurement of environmental contamination, and of health effects (i.e. morbidity) through epidemiological studies;
use of computer models, on dispersion/concentration of nuclides in the environment, and on the evaluation of doses to critical groups and to populations.
In practice, the two approaches are complementary, and linked: measurements are needed as for input and benchmarks for models, and models are used to establish monitoring priorities in the environment and epidemiological studies.
Figure 1 illustrates successive steps taken in an evaluation of environmental and health risks from reprocessing operations based on models, and the areas of associated uncertainties. This is similar to the approach used by GRNC (Groupe Radioécologie Nord-Cotentin) in their evaluation of health risks around the La Hague plant. Each step uses models, sometimes validated by measurement, and each involves many parameters and the use of many assumptions, which result in high levels of uncertainty. After a brief description of the steps is given below, the main uncertainties lying in this evaluation process are discussed in relevant chapters of the report [on some of the uncertainties found in these approaches, see Smith et al, 1998; IPSN, 2001].
The starting point is the set of assumptions used in computer models to assess nuclide inventories in spent fuel. Data on spent fuel reprocessed, especially its type, initial enrichment and burnup, are used in computer codes to calculate the nuclide content of spent fuel, hence the input of various nuclides into the reprocessing plant. To assess actual discharges, detailed knowledge (based on theoretical calculations by the plant engineers) of the physical and chemical processes in the plant, leading to the release of nuclides to air and sea is required. These releases are verified through material balance assessments in the plant, which will include stack measurements of discharges.
This results in the nuclide inventories in gaseous and liquid discharges. Then physical data on the nuclides, and their behaviour in relevant environments are used to estimate their concentrations in the environment. The estimates derived from these tranport models have to be validated by measurements in the environment. Local data are used for local and national models, rather than global models. In the case of certain long-lived nuclides, global transport models are also necessary.
Estimates of concentrations in the environment allow for the evaluation of doses to critical groups and to populations through the definition of exposure scenarios. Finally, models of the dose-effect relation, like those defined by the ICRP, are used to estimate the heath risks.
Figure 1 Uncertainty in the Evaluation of Environmental and Health Risks from Reprocessing Operations
STEP 1Reprocessing operationsSpent fuel features
Processes features Computer codes
Material balanceSTEP 2Activity of radionuclides
in liquid and gaseous dischargesCharacteristics of radionuclides
Environmental features Model
of transportSTEP 3Activity of radionuclides
in the environmentScenarios for external
and internal exposure Model
of exposureSTEP 4Doses (to individuals or populations)
from exposureDose / effect
relation Model
of riskSTEP 5Health risks
Case Study Sellafield
National Regulatory Framework
The United Kingdom has developed a large set of national nuclear regulations in the five decades its atomic energy programme has been in operation.
The Food Standards Agency which has the legal status of a Government department but without a minister also plays a role in nuclear regulation and radiological protection in the UK.
The first nuclear regulation dates to the passing of the Radioactive Substances Act in 1948. Next came the Atomic Energy Act in 1954, followed by the revised Radioactive Substances Act in 1960. In 1959, a White Paper covering the proposed policy framework was published on radioactive waste, including discharges. This was followed in 1965 by the Nuclear Installations Act, consolidating earlier legislation, covering the licensing of nuclear sites, including reprocessing plants.
The most relevant recent legislation, or draft legislation in process covering radiological protection includes:
Radioactive Substances Act 1993: Regulation of Radioactive Discharges;
Variations to the BNFL Sellafield Radioactive Waste Discharge Authorisations: Decisions of the Secretary of State for the Environment, Transport and the Regions and the Minister of Agriculture, Fisheries and Food;
UK Strategy for radioactive discharges 2001-2020.
In recent years, the United Kingdom government has increased the opportunity for citizens to be consulted policy review via submissions to official Consultations, including the House of Lords Consultation on Radioactive Waste strategy (1998-99); the Environment Agency Consultation on proposed revision of authorisations for technetium 99 and other radioactive waste discharges from Sellafield (2000); and the DETR Consultation on UK Strategy for Radioactive Discharges, 2001-2020 (2000). In addition there is a five part Consultation on discharges and other aspects of the MOX fabrication plant (SMP) at Sellafield, first by the Environment Agency in 1997-98, then by the DETR in 1999, and 2001.
Operations at Sellafield
Reprocessing has been carried out at Sellafield (originally Windscale) since the early 1950s, when the purpose was to separate plutonium for nuclear weapons. Table 1 sets out annual tonnage throughputs since 1970. Early data concerning reprocessing by the (now shut) B204 reprocessing plant is unavailable. Since 1965, the B205 fuel reprocessing plant at Sellafield has been operating principally for commercial purposes. The B205 plant reprocesses Magnox fuel, i.e. metallic uranium fuel clad in magnesium alloy from Magnox gas-cooled reactors. These reactors are in the process of being phased out by about 2010.
Approximately 26,000 tonnes of spent fuel have been reprocessed by the B205 line at Sellafield up to year ending 2000. Estimates vary as to how long reprocessing will continue at B205 [see discussion in RWMAC, 2000] but an informed estimate would be about 2012 based on current annual throughput rates.
The THORP (THermal Oxide Reprocessing Plant) plant started operations in 1994 to reprocess uranium oxide fuel in stainless steel cladding from Advanced Gas-cooled Reactors (AGR) and Light Water Reactors (LWR). So far about 3,200 tonnes of oxide fuel have been reprocessed at THORP.
No new reprocessing contracts (domestic or overseas) are likely at THORP. Estimates vary as to how long reprocessing could continue at THORP [RWMAC, 2000] under current contracts but an informed estimate would be also about 2012 based on its lifetime throughput rate.
Table 1 Annual Fuel Throughputs at B205 and THORP (financial years April-April)
YearMagnox B205YearMagnox B205THORP1971-728801986-879831972-736741987-888041973-749351988-898751974-759951989-901,1291975-765531990-917391976-771,1301991-928191977-788231992-937281978-796661993-941,6641979-808031994-951,059651980-818591995-961,5902081981-829231996-976014081982-838931997-985207811983-848601998-994654611984-857811999-005008791985-867052000-01366362Total~25,000 =SUM(ABOVE) 3,164Sources: CEGB reports, CORE reports, 1971-2 to 83-84 from CEGB reports, 1984-85 to 92-93 from BNFL Data Book. BNFL to again shut Sellafield plant to boost reprocessing of Magnox fuel Nuclear Fuel Vol. 25 No. 16, Aug. 7, 2000; BNFL Annual Reports.
Releases from Sellafield
Releases from Sellafield are presented below. Emissions to air are presented in Figure 2. Liquid discharges are presented in Figures 3a and 3b: light and heavy nuclides (mainly activation products) in the second one, and others nuclides (mainly fission products) in the first one. The reason for the division into two graphs is merely to present the mass of data points more clearly, not because there is any difference between their treatments at Sellafield. Logarithmic Y-axes are used to encompass the wide ranges of data. It should be noted that logarithmic scales do not show small fluctuations in data points.
Air Emissions
It may be seen from Figure 2 that radioactive air emissions at Sellafield have not varied to a marked extent since the 1970s, with the possible exception of iodine 129 emissions which have increased 10 fold in this 20 year time period. As stated in Chapter 4, radiation protection concerns exist over iodine 129, which has a 16 million year half-life.
The question of the contribution of carbon 14 releases from the Calder Hall reactors to global Sellafield releases was raised during the research. According to the UK Environment Agency it is insignificant: Carbon 14 aerial discharges from Calder Hall nuclear power station are small compared to Magnox Reprocessing and THORP and represent only a small percentage (2.3%) of discharges from Sellafield. Carbon 14 is currently discharged to air from the power station without abatement.
Figure 2 Annual Air Emissions from Sellafield Reprocessing Operations, 19761999 (TBq)
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Source: BNFL Annual Reports on Discharges and Monitoring of the Environment
Liquid Discharges
With liquid discharges to sea, the picture is more complex. In the late 1970s, very high levels of fission products and actinides (particularly plutonium isotopes) were contained in pond liquors discharged to sea. These discharges occurred as a consequence of Magnox fuel assemblies being held in ponds for long periods awaiting reprocessing. This resulted in the disintegration of many assemblies and in heavy radioactive contamination of pond liquids. These were subsequently discharged untreated to sea.
In the early 1980s, discharges of carbon 14, strontium 90, caesium 134 and caesium 137 declined markedly as a result of the introduction of a new abatement plant, the Site Ionisation and Exchange Plant (SIXEP) at Sellafield. However, in the mid 1990s smaller increases occurred in carbon 14, cobalt 60, strontium 90, technetium 99 and iodine 129 discharges.
It is understood from the Commissions comments [see European Parliament, undated] that these increases resulted from the reprocessing of older oxide fuels at Sellafield. Technetium 99 increases resulted from the commencement of treatment of 14 years arisings of Medium Activity Concentrate wastes from Magnox reprocessing which had previously been stored. These wastes were treated by the new Enhanced Actinide Removal Plant (EARP) at Sellafield. Over the same timespan, there has been a notable decline in actinide discharges, partly due to the commencement of EARP operations.
Figure 3a Annual Liquid Discharges from Sellafield Reprocessing Operations, 19761999 (TBq) Cobalt-60; strontium-90; technetium-99; iodine-129; caesium-134, 137
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Source: BNFL Annual Reports on Discharges and Monitoring of the Environment
Figure 3b Annual Liquid Discharges from Sellafield Reprocessing Operations, 19761999 (TBq) Tritium; carbon-14; plutonium (alpha, -241), americium-241
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Source: BNFL Annual Reports on Discharges and Monitoring of the Environment
Technetium Discharges
In recent years, concern has been expressed by Member States (including Denmark and Ireland) over technetium discharges from Sellafield. Technetium does not exist naturally in the environment: all concentrations found in the biosphere and hydrosphere are man-made. Technetium 99 is mobile in the environment, and has a half-life of 214,000 years, which means that its distribution will eventually be global. It should be noted that technetium discharges result mainly from Magnox reprocessing: it occurs in light water reactor fuel and thus in current La Hague discharges only in relatively low concentrations.
Figure 4 examines annual technetium discharges from Sellafield in more detail. It will be seen that between 1977 (when measurement of technetium discharges commenced) and 1980, technetium discharges were high due to the direct discharge of Medium Activity Concentrate (MAC) wastes as mentioned above. Between 1981 and 1993, MAC wastes were stored in tanks, then from 1994 they were treated in the new EARP plant for the enhanced removal of actinides and caesium isotopes. This plant however does not remove technetium 99 (and has relatively low removal rates of strontium 90, cobalt 60 and carbon 14 as seen from Figures 3a and b). This lack of removal capability was known in the early 1990s during the planning stages of EARP. However the decision was then taken that the increased cost of additional abatement plant to reduce technetium 99 (and other nuclide) discharges was not worthwhile. The result is seen below in the evolution of discharges, although they have been generally declining since 1995. In November 2000, the UK Environment Agency proposed to permit annual technetium discharges of 90 TBq (million millions or trillion becquerels) from Sellafield. This matter is still the subject of a formal Consultation procedure in the UK.
Figure 4 Annual Technetium-99 in Liquid Discharges from Sellafield, 19781999 (TBq)
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Source: BNFL Annual Reports on Discharges and Monitoring of the Environment
Expected Future Sellafield Discharges
Internal BNFL documents [BNFL, undated] leaked to the UK press and environmental groups in June 2001 suggest that BNFL envisages increases in nuclide releases in the future, as shown in Figures 5 and 6. The document, which contains detailed analyses of current and expected discharges, states as regards liquid discharges: Comparison of the total worst case discharge with the current authorised limits (
) shows that discharges of over half of the currently authorised radionuclides are predicted to be at levels approaching or above the limits.
Figure 5 Past and Projected Liquid Discharges from Sellafield Reprocessing Operations, 19902008 (TBq, Index 1 in 1990)
OSPAR (PARCOM 91/4): The contracting parties (
) agree (
) to apply the Best Available Technology to minimize and, as appropriate, eliminate any pollution caused by radioactive discharges.
OSPAR (PARCOM 93/5): Contracting parties (
) agree (
) to adopt further measures, including the application of Best Available Techniques for the reduction or elimination of inputs of radioactive substances to the maritime area.
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Source: [BNFL, undated]
A similar situation was expected with aerial releases from Sellafield: A number of predicted worst case discharges are close to or exceed the current annual authorisation limits, which implies a risk that these limits could be breached in future as a consequence of normal activities.
Increases of Sellafield releases would conflict with the UK Governments obligations set out in various OSPAR resolutions that call for the reduction and eventual elimination of radioactive discharges into the environment.
Figure 6 Past and Projected Gaseous Emissions from Sellafield Reprocessing Operations, 19902008 (TBq, Index 1 in 1990)
OSPAR (PARCOM 91/4): The contracting parties (
) agree (
) to apply the Best Available Technology to minimize and, as appropriate, eliminate any pollution caused by radioactive discharges.
OSPAR (PARCOM 93/5): Contracting parties (
) agree (
) to adopt further measures, including the application of Best Available Techniques for the reduction or elimination of inputs of radioactive substances to the maritime area.
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Source: [BNFL, undated]
Impact of Sellafield Discharges
Plutonium and other actinides near Sellafield
When radionuclides are discharged into the sea from Sellafield, some (e.g. fission products caesium-137 and technetium-99) are soluble and diluted in large volumes of seawater. Others (notably plutonium) tend to be concentrated in sediments close to Sellafield, in the Irish Sea and in the Solway Firth. Up to 1995, discharges into the sea of plutonium (alpha) and americium 241 from Sellafield amounted to about 1,600 TBq. Kershaw et al [1992] estimate that at least 240 TBq of plutonium 239/240 remains bound to the seabed within a coastal strip approximately 30 km wide, running from Kirkcudbright Bay to the Ribble estuary in the south. The quantity outside this zone amounts to about 40 TBq of plutonium 239/240.
Radionuclide deposition around Sellafield was analysed by Day [1992]. Plutonium deposition plots show two main features: a major deposition peak centred on Sellafield falling sharply with distance, and a minor peak, centred a short distance inland from the Ravenglass Estuary. The peak centred on Sellafield dominates the plutonium deposition map for this part of Cumbria. A slightly raised level of deposition is also apparent along the coastal strip. Peak values of plutonium concentration are about three orders of magnitude higher than the concentrations due to weapons fallout. Day concluded the plutonium deposited within 20 km of Sellafield attributable to aerial emissions was 160-280 GBq, compared with 90 GBq from bomb fallout.
A potentially important pathway for discharged radioactive material to humans involves sea-to-land transfer. Although this mechanism was disregarded before 1980, it has since been established that significant quantities of radionuclides can become airborne in sea spray and be transported inland by the wind [McKay and Pattenden, 1990]. Actinides with an activity of 2.5x105 Bq, equivalent to about 1,000 body burdens, can be transported inland relatively quickly. The average activity due to actinides is 40 µBq/m3 15-120 m from the sea, and may occasionally exceed the ICRP limit of 1 mBq/m3 [Branford, 1994].
From these data, the scale of past nuclide discharges from Sellafield may be seen to be large. Consequent concerns have been expressed about resulting nuclide concentrations in the environment. For example, Lambert [1989] and Aarkrog [1997] have estimated that over 40,000 TBq of caesium 137, 113,000 TBq of beta emitters and 1,600 TBq of alpha emitters have been discharged into the Irish Sea since the inception of reprocessing at Sellafield. Baxter [1991] has observed that this means between 250 and 500 kilograms of plutonium from Sellafield is now adsorbed on sediments on the bed of the Irish Sea. Hunt and Smith [1999] have commented that a storm could bring contaminated sediment onshore, leading to increased doses to critical groups in the years following the event. Baverstock [1997] has stated that the migration of undersea deposits of actinides to coastal environments represents a long-term hazard of largely unknown proportions.
Apart from bomb test fallout, past discharges at Sellafield are easily the largest anthropogenic discharges of radioactivity to the oceans. Current discharges from Sellafield and La Hague still rank among the largest anthropogenic releases of radioactivity in the world.
Estimated Doses from Consumption of Irish Sea Fish and Shellfish
The main pathways of radiation exposure for those living near Sellafield are: (1) external radiation from both airborne and deposited radionuclides; (2) internal exposure after inhalation of airborne radionuclides; and (3) ingestion of radionuclides present in foodstuffs.
In the Sellafield area, the critical group is now thought to consist of members of the local fishing community who consume significant quantities of locally caught fish and shellfish. This is contaminated with a number of radionuclides; plutonium and americium are particularly important from the point of view of potential toxicity.
The RIFE-5 report [FSA, 2000], sets out estimated doses to consumers of seafood from the Irish Sea. Those are presented in Annex 7. It will be seen that these estimated doses are relatively low in comparison with the current UK dose constraint of 0.3 mSv/a.
Doses to Critical Groups
A recent review [Jackson et al, 2000] of critical groups doses states that, during the 1970s and 1980s, peak doses possibly reached 2.5 to 3.0 mSv per year. Latterly, doses to marine-related critical groups have declined to less than 0.15 to 0.2 mSv per year.
Although there has been a comprehensive programme of environmental monitoring in recent years, there has been limited monitoring, i.e. body scans, of radionuclides in members of the public living near Sellafield. A rather dated study carried out by the UK Ministry of Agriculture (the precursor to the FSA) and the National Radiological Protection Board (NRPB) in 1984-85 found that caesium-137 body contents of 16 adult fish and shellfish consumers near Sellafield were only about one third of predicted values [Hunt et al, 1989]. However, measurements of plutonium in autopsy tissues taken at the same time showed higher concentrations in Cumbria [Popplewell et al, 1985].
Environmental Concentrations
Changes between 1989-1999
The latest RIFE-5 [FSA, 2000] report of the UK Food Standards Agency includes tables that chart concentrations in seafoods from Sellafield between 1989-99. Concentrations of the main radionuclides (carbon 14, technetium 99, caesium 137, plutonium 239 and plutonium 240, americium 241) are measured in winkles, lobsters and cod. These results are presented in Annex 8.
It may be seen from these figures that caesium 137 and transuranic concentrations in seafoods have been generally declining over the past 10 years, reflecting the continuing decline in caesium and alpha emitters from Sellafield in the same period. The same picture of concentrations in seafood following carbon 14 and technetium 99 discharges is also apparent.
Detailed Concentrations in Fish, Shellfish, Sediments and Aquatic Plants
1999 environmental measurements of key nuclides in fish, shellfish, sediments and aquatic plants close to Sellafield are set out in Annex 9a. The same measurements have been made in biota at greater distances to indicate the distribution of radioactive pollution from Sellafield. The data in these tables are obtained from the latest UK RIFE-5 report [FSA, 2000]. In these tables, a number of high concentrations were recorded, some exceeding European Community Food Intervention Levels (CFILs). These high levels give some cause for concern and they have been marked in red for ease of reference.
CFILs were introduced by Council Regulations (Euratom Nos 3954/87, 944/89 and 2218/89) following the Chernobyl accident to restrict the import of contaminated foodstuffs to Europe. These limits in force at present are set out in Table 2.
Table 2 Community Food Intervention Levels (Bq/kg)
Baby FoodsDairy ProduceOther FoodsIsotopes of strontium (notably 90Sr)75125750Isotopes of iodine (notably 131I)1505002,000Alpha-emitting isotopes of plutonium and transplutonium elements (notably 239Pu, 241Am)12080All other nuclides of half-life greater than 10 days (notably 134Cs, 137Cs) (1)4001,0001,250(1) The following radionuclides are not included in this group: tritium, carbon 14, and potassium 40.
Source: Council Regulations, Euratom Nos 3954/87, 944/89 and 2218/89
These environmental concentrations result in small but measurable radiation doses to local people (see Tables in Annex 9a) discussed below. RIFE-5 report states that the dose to the Sellafield Critical Group from current discharges was 0.21 mSv, c.f. the UK dose constraint of 0.3 mSv. The UK NRPB continues to conclude that radiological hazards from consuming marine foodstuffs at these levels are acceptable.
Technetium Concentrations
Technetium-99 Concentrations in Marine Samples
As a result of elevated technetium discharges in the mid 1990s, technetium concentrations in marine biota in the Irish Sea near Sellafield increased. After 1994, technetium 99 concentrations in crustacea particularly in lobster , rose reaching a peak of about 16,000 Bq/kg in 1997. This level is 13 times the European Council Food Intervention Level (CFIL) for technetium-type nuclides (1,250 Bq/kg) in post-accident situations. Concentrations in local lobster have subsequently declined, reflecting a reduction in technetium 99 discharges: the highest measurement in 1999 was 4,700 Bq/kg. Figure 7 shows the annual trend of technetium concentrations in lobster.
Some technetium 99 concentrations above CFIL limits have also been found in molluscs (winkles, mussels, limpets and whelks) in the vicinity of Sellafield. In 1995, technetium 99 concentrations in local winkles reached 1,600 Bq/kg [Environment Agency, 2000]. However, generally speaking, technetium concentrations in local molluscs are a factor of 10 lower than in lobsters, and a factor of 1,000 lower in cod. The reasons for these widely divergent concentration factors in marine biota are presently not known.
1996-1997 surveys in Norwegian coastal waters showed technetium 99 concentrations in seawater had increased tenfold compared with 1991 concentrations. This matched the scale of increase observed in the Irish Sea near Sellafield. The travel time from Sellafield to Norway for the initial (1994) pulse of technetium 99 contamination was estimated at about 2.5 years. Recent environmental surveys along the Norwegian coast reportedly indicate a six fold increase in technetium 99 concentrations in seaweed since 1996 i.e. from 100 to 600 Bq/kg dry weight.
These technetium concentrations result in elevated collective doses to critical groups near Sellafield, and in high collective doses not only to local and UK populations, but also to European and global populations.
Figure 7 Technetium-99 Concentrations in Lobster, in Bq/kg wet weight, 1986 to 1998
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Source: Annual MAFF and RIFE Reports
Uptake of Technetium-99 by Marine Plants and Animals
In order to estimate the concentrations of technetium 99 in elements of the marine environment for a given level of discharge, computer models are necessary. These models consist essentially of two main parts:
(1) a model to predict the dispersion of technetium 99 in seawater currents and
(2) a model to predict the uptake of technetium 99 from seawater into marine plants and animals. Both modelling stages have associated uncertainties.
A Working Group set up by the Commission of the European Communities used the MARIN1 suite of computer models to estimate the dispersion of radionuclides in northern European waters and their consequent radiological impact. In 1990 they reported that:
As a tracer radionuclide, 99Tc suffers somewhat from the limited availability of monitoring data. (...) although MARIN1 adequately predicts water concentrations in seas around the British Isles, describing 99Tc dispersion to within factors of a few of measured concentrations, it tends to underestimate at greater distances from the reprocessing plants over the same period. This may be due, in part, to the accuracy of values used in the model for exchange rates in these waters. Any deficiencies in the modelling of 99Tc with regard to transfer coefficients are likely to be compounded by uncertainties in the choice of concentration factor used....in addition to the above uncertainties in the modelling of 99Tc dispersion and uptake, it should be noted that there is also uncertainty about discharges of technetium from Sellafield prior to 1978. [MARINA Project, 1990]
The concentration factor referred to above is the ratio of technetium 99 activity in the tissue of a plant or animal to the activity in seawater. Only limited data are available on technetium-99 concentration factors; there are large and real inter-species differences [Dehut et al,1990].
Both aerobic and anaerobic marine bacteria from coastal sediment are capable of concentrating technetium [Vandecasteele et al, 1989]. This may result in the transfer of technetium-99 to higher levels in the food chain. Concentration factors are greater than 1,000 for some biota such as macrophytic brown algae, worms and lobsters [Masson et al, 1989]. Concentration factors for some seaweeds are particularly high for example, that for Fucus vesiculosus is around 100,000 [Dahlgaard et al, 1997].
A recent study of technetium 99 activity in Cumbrian seafood found concentration factors of between 380 and 1,200 in lobster muscle tissue (the part most commonly consumed by man), 7,700 in the hepatopancreas and 65,000 in the green gland. In Nephrops (the Norwegian lobster) the concentration factors are 1,700 for claws and 970 for abdomen muscle. The tail muscle (the part of Nephrops most commonly consumed by man) had a higher activity than the average level in lobster, although the authors of the study do not actually report the activity.
Several studies have estimated concentration factors using laboratory experiments, but concentration factors in the marine environment have been found to be one to two orders of magnitude higher than in laboratory experiments [Masson et al, 1989]. For example, Busby et al [1997] reported concentration factors in winkles and mussels much greater than any reported from laboratory investigations (>100X in some cases). McCartney & Rajendran [1997] in a study of technetium 99 activities in seaweeds, muscles and winkles confirmed that the uptake (of technetium 99) by marine organisms in the field far exceeded that expected from laboratory studies. They concluded that, given the radiological importance of this nuclide, the provision of more accurate information on its environmental behaviour was required.
It should be noted that ingestion of seafood containing technetium 99 may not be the only pathway by which humans incur radiation doses. In some areas, seaweed is used as agricultural fertiliser. A report published by Atomic Energy Authority Environment and Energy at the Harwell Laboratory [Nicholson et al, 1992] estimates that, if seaweed were used in this way, individual doses from this pathway alone could be around 260 µSv per year (assuming a discharge rate of 200 TBq per year).
Our present understanding of the behaviour of technetium-99 was summarised by Zeevaert et al [1989].Despite the substantial amount of quantitative information about the transfer of technetium in the biosphere that has recently become available, large uncertainties in this field persist. Twenty years ago in a key study, Ng [1982] warned that long-term extrapolations based on short-term experiments were risky: this warning remains relevant. This remains the case in 2001.
A recent study carried out on behalf of the German Office for Radioprotection [Beninschke, 2000], using German statutory dose assessment assumptions, calculated the dose impact of seaweed use as fertiliser. Annual induced effective doses from consumption of contaminated foodstuffs were 5.88 mSv for adults and 5.82 mSv for children. That is more than 5 times the annual limit imposed by the European legislation (1 mSv per year) and about 20 times the annual dose constraint used in UK and Germany (0.3 mSv per year). Most of the calculated dose was received via the seaweed fertiliser/animal feed/meat consumption pathway. The authors used the consumption habits, transfer factors and other assumptions prescribed by German legislation. European legislation does not prescribe specific assumptions in dose assessment models. The European Commission has stated that the guidance currently being produced on realistic dose assessments will comment on this issue.
This raises the question of the differences between the values used for consumption habits and life patterns in models used by national authorities to calculate doses to individuals near reprocessing plants and other nuclear facilities. The European Commission has stated that it is working to prepare guidelines on the harmonisation of realistic assessment of doses. Article 45 of the new Basic Safety Standards Directive indeed states that Member States competent Authorities shall ensure that dose estimates from practices subject to prior authorisation shall be made as realistic as possible for the population as a whole and for reference groups. However it is noted that Article 45 concerns population (i.e. collective) doses rather than individual doses.
The German Federal Office for Radiation Protection recently stated: On the question what is realistic, there is no consensus visible on the short term on the EU level. A corresponding examination in national and international framework is considered urgently necessary.
Conclusions on Concentrations and Doses
National radiological authorities state that radionuclide concentrations in local contaminated materials continue to result in doses to critical groups that fall within agreed safety limits. These conclusions are reached after dose estimates have been arrived at through the use of computer models using many assumptions and estimated parameters. Although these dose estimates are best estimates arrived at using the best endeavours of regulatory teams in both countries, nevertheless large uncertainties remain. For example, the NRPB [Smith et al , 1998] has concluded that uncertainties in dose estimates via the food chain may be very large: differences between 5th and 95th percentile values, for example, often exceeded three orders of magnitude.
These uncertainties are discussed further in Annex 10.
In addition, the effects of historical discharges are not considered when comparing radiation doses with the dose constraint. This is an important factor as these doses from past discharges at Sellafield are considerably greater (probably by a factor of 3) than doses from current discharges.
Also as discussed above, current concentrations of radionuclides in the marine environment near Sellafield could already lead to doses that exceed the UK and German constraint by a factor of 20 and the current European limit by a factor of 5 for a reference person [Beninschke, 2000], with food consumption patterns as defined in the German legislation. The conclusion would appear to be that the Sellafield facility would not be suitable to receive a license to operate in Germany at current levels of discharge.
In addition, German dose limits for organs (also used in the US but not in the rest of the EU) would also be exceeded by the ingestion of relatively small quantities of seafood from Sellafield. For example:
consumption of 3.41 kg of winkles from St. Bees in the vicinity of Sellafield is sufficient to reach the adult limit for bone surface [Beninschke, 2000, see Table 5.1-11];
consumption of 11.6 kg of food grown on soil fertilised with contaminated seaweed from the Irish Sea is enough to reach the dose limit for the lower colon of a small child [id., Table 5.1-16];
consumption of 4.44 kg of meat of beef fed with seaweed from the Irish sea is enough to reach the dose limit for the lower colon of an adult [id., Table 5.1-19]; the consumption of 0.6 kg is enough to reach the limit for small children [id., Table 5.1-20].
The Hazard Posed by Liquid High Level Waste at Sellafield
Reprocessing at Sellafield has generated large inventories of radioactive waste, in various physical and chemical forms. A substantial part of this waste is in readily-mobilisable forms, including liquids and sludges. The potential exists for unplanned releases of radioactive material from the Sellafield waste inventories. This potential is especially great where the waste is held in a readily-mobilisable form.
The largest hazard of this kind is posed by the storage of high-level radioactive waste (HLW) as a liquid. The loss of cooling to a High Active Liquor feed vessel was also considered as a reference accident by the UK authorities in the case of Sellafield in their General Data submission to the European Commission. Reprocessing at the B205 and THORP facilities produces comparatively dilute liquid HLW, and this liquid is transferred through shielded overhead pipelines to the B215 facility. There, the concentration of the liquid HLW is increased in evaporators, and the concentrated liquid is stored in 21 above-ground steel tanks. The liquid HLW is self-heating due to the very high levels of radioactive decay. This method of storing HLW has been used since reprocessing began at Sellafield in the 1950s, and was adopted because it is comparatively inexpensive.
The concentrated liquid HLW in the tanks is hot and acidic, and requires constant cooling, agitation and supervision. If cooling were to be interrupted, the liquid could begin boiling after about half a day and evaporate completely over a subsequent period of about three days, leaving a solid residue that would oxidise and melt. Volatile radionuclides such as caesium-137 would be evaporated from the solid residue and could pass through the ventilation system to the atmosphere.
Caesium-137 is an important indicator of the hazard potential of the liquid HLW at Sellafield. This fission product is volatile, and is therefore released to the environment in comparatively large quantities during accidents at nuclear facilities. Caesium-137 has a half-life of 30 years, adheres to surfaces when deposited from an atmospheric plume, and emits intense gamma radiation. The 1986 Chernobyl reactor accident released about 85,000 TBq (27 kg) of caesium-137 to the atmosphere, accounting for most of the offsite radiation exposure from the accident. For comparison, the 1,300 cubic metres of liquid HLW, currently stored at Sellafield [NII, 2000c], contain about 7 million TBq (2,100 kg) of caesium-137 [Thompson, 1998, Appendix D].
Analyses have shown that influences such as human error, equipment failure, natural forces (e.g. earthquake) or acts of malice could initiate a sequence of events that releases a substantial fraction of the radioactive material in the liquid HLW tanks to the environment, either as an atmospheric plume or as a liquid release to the Irish Sea. Events that could breach a tank and its surrounding concrete cell, leading directly to a liquid or atmospheric release, include an explosion, aircraft crash, earthquake or act of sabotage. A larger atmospheric release could arise indirectly from such events. The initial event an explosion, for example could disable tank cooling systems and radioactively contaminate the vicinity of the affected tanks to a level that would preclude the restoration of cooling. Then, the affected tanks would dry out, and volatile radionuclides would evaporate from the solid residue. This release could contaminate the vicinity of the tanks to a higher level, precluding the ongoing provision of cooling to unaffected tanks. Thus, the initial event could ultimately lead to an atmospheric release from every tank that contains liquid [Thompson, 1998].
In 1957, an atmospheric release occurred from a liquid HLW tank at a military reprocessing plant near Kyshtym, USSR, when the tank dried out and exploded. Reprocessing plants are prone to chemical explosions, as is shown by incidents in Japan, the United States and Russia/USSR. A particular concern at Sellafield is the potential for an explosion in one of the evaporators at the B215 facility, due to inadvertent forwarding of organic chemicals from the B205 or THORP reprocessing plants. An explosion in an evaporator could ultimately lead to an atmospheric release from every liquid HLW tank, as explained above [Thompson, 1998, Appendix G].
The long-term consequences of a release from the Sellafield HLW tanks could be much greater than the consequences of the Chernobyl accident, due to the large amounts of caesium-137 and other radioisotopes in the Sellafield tanks. According to the US Department of Energy (DOE), the Chernobyl release caused a 50year Northern Hemisphere population dose commitment of 1.2 million person-Sv, primarily from the 90,000 TBq of caesium-137 in the release [DOE, 1987]. An atmospheric release from the Sellafield HLW tanks could include a substantial fraction of their inventory. Assuming a 50 percent release (3.5 million TBq of caesium-137), extrapolation of the DOEs Chernobyl estimate would yield a 50-year Northern Hemisphere population dose commitment of 47 million person Sv from a Sellafield release. This extrapolation should not be regarded as more than a crude estimate of the consequences of a possible Sellafield release, because of the different characteristics of the Chernobyl accident and the postulated Sellafield release, but the result illustrates the potential order of magnitude of the consequences. In 1994, the COSYMA computer model assessed the consequences of an atmospheric release from the Sellafield HLW tanks, to range up to tens of millions of person-Sv [Taylor, 1994].
In 1976, about 600 cubic metres of liquid HLW was stored at Sellafield, and it was predicted that about 6,000 cubic metres would be stored in 2000 [Flowers et al, 1976, page 64]. The present volume about 1,300 cubic metres is lower because the scale of reprocessing at Sellafield has been lower than predicted, and because vitrification of liquid HLW has been proceeding since 1991. The liquid HLW is transferred from the B215 tanks to an adjacent vitrification plant, where it is incorporated into glass that is cast into steel containers. The containers are stored in a vault where they are cooled by the natural circulation of air. The UK Nuclear Installations Inspectorate (NII) has described the cooling arrangement in this vault as follows: This cooling does not depend on the continued availability of installed services such as electricity and water, and is sometimes referred to as passively safe. This may be compared with the situation in B215 where active systems, requiring operator control, are needed to keep the HAL [liquid HLW] in a safe state. [NII, 2000c, page 4] Production rates at the vitrification plant have been insufficient to eliminate the backlog of liquid HLW stored in the B215 tanks. Thus, BNFL has predicted that the volume of liquid HLW will rise by about 10 percent during the period 2000-2004, after which the volume will begin to fall.
BNFL and the NII have been slow to investigate or take action about the hazard posed by the liquid HLW tanks. This hazard was debated during the Windscale Inquiry of 1977, but no action was taken. Public concern about the hazard arose during the 1990s, initially in the context of the commissioning of THORP, and has continued at a high level. In response to ongoing public concern the NII eventually required BNFL to perform safety analyses and to undertake repairs and modifications to the B215 facility. However, neither BNFL nor NII has ever published any of its safety analyses for B215.
In January 2001, the NII issued BNFL with a Specification (a legal order), which limits the volume of liquid HLW to 1,575 cubic meters, lowers this limit by 35 cubic meters per year until 2012, and requires a subsequent reduction to 200 cubic meters in 2015; thereafter, BNFL would be permitted to store 200 cubic meters of liquid HLW as a buffer stock [NII, 2000c]. This Specification is designed to accommodate BNFLs business plan, and to minimise the cost and inconvenience to BNFL of reducing the stock of liquid HLW.
Although the liquid HLW tanks at B215 pose the largest hazard of an unplanned release at Sellafield, this hazard is not unique. Other facilities at Sellafield contain significant amounts of radioactive material, often in a readily-mobilisable form. Transport of radioactive material to and from Sellafield also creates a potential for unplanned releases. Analytic techniques known as probabilistic risk assessment (PRA) have been developed, whereby the probability and consequences of unplanned releases can be investigated. PRA findings, properly applied, can provide a basis for public debate about the hazard posed by a nuclear facility, and can guide regulatory action to address that hazard. No PRA study has ever been published for any facility at Sellafield or any transport operation associated with Sellafield, although BNFL officials have conceded that the preparation and publication of PRA studies would be required if the Sellafield site were licensed in the United States. There is evidence that the quality of BNFLs unpublished safety analyses does not meet contemporary PRA standards [Thompson, 1998; 2000b].
Health Effects at Sellafield
The attribution of possible health effects to contamination from radioactive discharges at Sellafield has proved difficult and contentious. Most controversy centres on the issue of childhood leukaemia and cancer.
Childhood Leukemia at Seascale
In 1983, the UK Yorkshire Television company produced a film which reported a higher incidence of childhood leukaemia in the village of Seascale, near Sellafield, than was expected from national incidence rates. The Prime Minister at that time, Margaret Thatcher, set up a Committee of Enquiry chaired by Sir Douglas Black. The Black Committee asked the National Radiological Protection Board (NRPB) to estimate the probable radiation doses to children in Seascale from the discharges. These calculations showed that, using conventional dosimetry and risk factors, the radiation doses likely to have been received from the discharges were too low (by a factor of >200) to result in the observed incidence of leukaemia [Stather et al, 1984 and Addendum]. Subsequently, a permanent Committee was set up to study aspects of radiation in the environment (Committee On Medical Aspects of Radiation in the Environment COMARE).
More than fifteen years of research has established that the excess incidence of childhood leukaemia around Sellafield is statistically significant, i.e. highly unlikely to be a chance finding. Craft et al [1993] examined the incidence of cancer in young people under 25 years of age in 1,272 census wards in the north of England in the years 1968-85 and found that, of the six electoral wards with the most extreme excesses of lymphoblastic leukaemia in young people under 25, two were close to Sellafield Seascale 3 km to the south (4 cases, expected 0.3) and North Egremont 7 km to the north (4 cases, expected 0.6).
A further study of the period 1963-90 by Draper et al [1993] showed that the incidence of malignant disease continued to be higher than expected in Seascale. COMARE concluded that the raised incidence of leukaemia and non-Hodgkins lymphoma in the young people of Seascale, and its persistence over several decades, were probably unique in the UK [COMARE, 1994]. As noted above, doses from environmental radioactivity were not thought high enough to explain the raised incidence of leukaemia.
Paternal Pre-Conception Irradiation
In 1990, an alternative explanation was offered by Martin Gardner and colleagues [Gardner, 1990] who showed an association between pre-conception radiation dose to a father and leukaemia risk in his children. Gardner estimated that a dose of 100 mSv or more to a father was associated with a six-fold increase of leukaemia risk in children born subsequently. The implication was that ionising radiation caused a mutation in the fathers sperm, which can be expressed as leukaemia in his children.
There remain several problems with this hypothesis [see Baverstock, 1993]. It is not consistent with the observed incidence of leukaemia in the survivors of Hiroshima and Nagasaki, nor is it supported by other studies of childhood leukaemia in the children of nuclear workers. More important, it would imply a rate of production of a specific mutation that was many times greater than the sum of all dominant mutation rates known to occur in humans [Doll et al, 1990]. The plausibility or otherwise of the Gardner hypothesis formed the central theme of two cases heard in the High Court of Justice, London, over the period October 1992 to June 1993. The plaintiffs in these cases claimed that the cause of a fatal leukaemia and a non-fatal non-Hodgkins lymphoma was paternal preconception irradiation (PPI) at Sellafield.
While the court cases were in progress, a study by Kinlen [1993] demonstrated that, contrary to earlier observations, the leukaemia excess included cases who lived (but had not been born) in Seascale. According to Kinlen, of the six cases born in Seascale five had high Parental Preconception Irradiation (PPI >90 mSv). Of five cases born elsewhere, only one was associated with high PPI. Kinlen concluded that the Gardner hypothesis could not account for all the cases in the Seascale cluster. Looking at the problem in another way, if the Seascale excess were entirely due to PPI, many more cases should have occurred in West Cumbria outside Seascale. As noted above, there is a significant cluster of leukaemia cases in Egremont North; but none of the fathers of these four cases had a recorded dose of PPI [Wakeford and Tawn, 1994]. These findings, together with the problems mentioned above, led the judge to find (in October 1993) in favour of the defendants (BNFL). However, the cause (or causes) of the increased incidence of leukaemia at Seascale remain(s) unclear.
Population Mixing
Kinlen et al [1991] have put forward a hypothesis that population mixing results in the spread of viral infections and that childhood leukaemia is a rare consequence of such an infection. This hypothesis appears to be supported by data on the incidence of leukaemia in England, Wales, and Scotland. However, Draper et al [1993] have pointed out that the high incidence in Seascale has occurred over an extended period, and was unlikely to be explained by Kinlens hypothesis, i.e. because population mixing stopped many decades ago. They also pointed out that the risk of childhood acute lymphoblastic leukaemia is doubled in isolated towns and villages, but the excess in Seascale is too large to be accounted for in these ways.
The possibility remains that ionising radiation is at least one of a number of causative factors. COMARE has stated:
The cause of the excess rate of cancer in the 0-24 year old age range in the village of Seascale is currently unknown. There are a number of possible causes, which may have led to this excess. There is insufficient evidence to point to any one particular explanation and a combination of factors may be involved. As exposure to radiation is one of these factors, the possibility cannot be excluded that unidentified pathways or mechanisms involving environmental radiation are implicated. [Bridges,1993]
In conclusion, the cause or causes of the observed increases in childhood leukaemia near reprocessing facilities are not known, nor is it known whether a combination of factors is involved. Many observers admit radiation is likely to be involved to some degree, but in the absence of working hypotheses, the question remains open. Further consideration of possible explanations is contained in Annex 11.
Other Possible Health Effects at Sellafield
Investigation of possible health effects due to Sellafield discharges has been dominated by the childhood leukaemia issue outlined above. However, some other areas of concern have also arisen.
Stiller [1993] has reported an increased incidence of retinoblastoma in children born to mothers who have lived in Seascale. In 1999, Parker et al [1999] reported a statistically significant increasing trend of stillbirth risk with PPI dose among the offspring of workers at the Sellafield nuclear reprocessing plant over the period 1950-89. However Little [1999] has countered that these findings should be interpreted with caution as they are inconsistent with observations in the Japanese Atomic Bomb survivors. This matter is discussed further in Annex 10.
Conclusions on Health Effects
A statistically significant excess of childhood cancer continues in the area around Sellafield, notably in the village of Seascale. COMARE has examined current leading hypotheses and pathways by which the observed excess could have come about and have been unable to find a convincing explanation. Nevertheless COMARE has recommended support for further research on a number of radiobiological aspects. This indicates that radiation as a possible cause of the cancers has not been discounted by COMARE. The authors have verified this in discussion with COMARE members in the UK. The assertion of the European Commission to the contrary among its replies [see European Parliament, undated] to the Committee on Petitions is incorrect.
Case Study La Hague
National Regulatory Framework
Hierarchically, the French regulatory framework governing the discharges of radioactive effluents in the nuclear sector can be divided into two levels :
- The general technical regulation
The monitoring of effluents discharged by Basic Nuclear facilities (Installations Nucléaires de Base or INB) is governed by the general technical regulations taken at ministerial level in application of the Decree n° 63 1228 of 11 december 1963 concerning nuclear facilities and the Decree 95 540 of 4 may 1995 concerning the discharges of liquid and gaseous effluents and water use of basic nuclear facilities.
- Fundamental safety standards
These are mainly recommendations drawn up by the Safety authority (Direction de la sûreté des installations nucléaire, DSIN also called Autorité de sûreté nucléaire, ASN) or codes established by the French nuclear industry. The DSINs recommendations are in no way legally binding regulations. The nuclear industry is not compelled to abide by them if it proves that alternative means were implemented to achieve the targets.
Authorisations of discharges
French regulations official acknowledgement of radioactive discharges from nuclear facilities dates back to the early 1960s. At the time, measures were adopted to regulate discharges in application of general laws such as the law of 2 August 1961 on atmospheric pollution and odours.
As far as La Hagues reprocessing activities are concerned, the first document to refer to radioactive effluents, is the Decree of 17 January 1974, of which Section E, Al. 3, explains that liquid and gaseous effluents are released in the ambient environment in compliance with the regulation in force. The CEA (Commissariat à lénergie atomique) had in fact applied for an authorisation to modify its treatment facilities, involving the presentation of the whole activities including discharges. The CEAs application for a license to discharge, dated 19 May 1972, introduced annual limits for effluents that were based on surveys that were neither referred to nor included in the document, and which were to become the basis for future authorisations of discharges.
It is only in 1980, 14 years after the facilities had started operating, that regulations specifying general annual maximum limits were issued to restrict COGEMAs radioactive discharges.
In fact, the departmental order of 22 October 1980 authorising COGEMA to release liquid and gaseous radioactive effluents fixed the annual limits for discharges. The limits were then confirmed by the prefectoral orders of 27 February 1984 and 28 March 1984 respectively for gaseous effluents, with:
480,000 TBq for gases other than tritium;
2,200 TBq for tritium;
110 GBq for halogenes;
74 GBq for aerosols. (Article 1)
and liquid effluents,
37 000 TBq for tritium;
1700 TBq for radio-elements other than tritium;
220 TBq for the totality of strontium 90 and caesium 137;
1.7 TBq for alpha radioelements. (Article 1)
In addition to the release of radioactive effluents, rainwater discharges from La Hague were also subjected in the 1980s to an authorisation procedure.
COGEMA was for instance authorised in the ministerial orders of 22 November 1988 to discharge rainwater into Saint-Hélène and Moulinets streams, provided that radioactivity tests are undertaken on regular basis.
There are three main disadvantages in the French authorisation system:
- firstly, it regulates annual limitations of discharges and not concentrations. The amount of effluents released into the sea may vary considerably from day to day, reaching sometimes significant peaks of discharges;
- secondly, the classification of the effluents given in the authorisations is far from being detailed (for example, they lack limits for each radionuclide) and the way they were categorised is questionable as far as some radionuclides are concerned.
- thirdly, significant levels of discharges are granted without public access to relevant underlying data that would allow for the justification of these figures.
Licensing Procedures
There are two different legal procedures COGEMA has to go through today, prior to any modification on its discharges into the environment:
Authorisation procedure
Applications for authorisations of discharges are addressed to the Ministers in charge of Industry and the Environment. It is also submitted for opinion to the Ministers in charge of Health and Civil Security.
They include general information on plans, programs, description of the concerned activities and their predictable impact on the environment, the compensatory measures proposed and the monitoring operations and further information that may be required by the concerned ministers.
The applications are then transmitted to the Prefect who orders a public inquiry and consults with the concerned municipal councils and regional bodies.
The results of the public inquiry and the different meetings are handed over to the Ministers of Industry and the Environment who take the decision to authorise the discharges.
The Ministers decision determines:
- the limits of discharges authorised for COGEMA,
- the operations of analysis, monitoring and control of these activities,
- the conditions in which the exploiting company gives account to the Ministers in charge of Health and the Environment and to the Prefect, of the water monitoring and the impact of effluents on the environment, and
- modes of information of the public
Notification procedure
Similarly, notifications are submitted to the Ministers in charge of Industry and the Environment.
In the case of discharges, they indicate the quantities of effluents and their composition as well as the conditions in which such activities are to be carried out. A document must provide the necessary information on the impact of the operation on the environment, and proposed compensatory or corrective measures.The Prefect and the municipality concerned by the discharges are sent a copy, which the public can consult, at the level of the city hall. The draft decision is sent to the company, which has 15 days to address written observations to the concerned ministers.
The DSIN has recently launched a procedure to review downwards the limitations of discharges of radioactive effluents from nuclear sites.
Supervision
The day-to-day monitoring and control of effluents are entrusted to the operator COGEMA itself, which is also charged with monitoring the impact of its discharges on the environment. COGEMA is by law impelled to record the results of its controls and transmit them to State control authorities. This self-control is, in principle, guaranteed by more-or-less independent State bodies, which by inspecting unexpectedly the La Hague facilities and checking COGEMAs records can tell whether (the limitations) are departed from.
Today, such inspections are provided for in Article 28 of the ministerial order of 26 November 1999 and are entrusted to three State bodies. In addition to the monitoring of the impact of radioactive discharges on the surrounding environment of La Hague, the State bodies, among which OPRI (Office de Protection contre les Rayonnements Ionisants), are charged with operations of inspections of COGEMAs monitoring laboratories and controls on the facilities effluents.
According to the DRIRE (Direction Régionale de lIndustrie, de la Recherche et de lEnvironnement), such controls were hardly undertaken by any State authorities in the 1960s. It is only in the 1980s that the DRIRE, as regional representative of the national safety authorities, organised inspections at La Hague on regular basis. Of 80 inspections carried out in 1999, 2 or 3 inspections concerned the discharges of effluents. However, the fact that the regulation in force provides for annual radioactivity limitation values only, the State control bodies have limited means to ensure that such yearly values are complied with, unless it is done through the control of the companys (COGEMA) records.
It is worth noting that until today, COGEMA has basically set its own concentration limits of effluents, which the inspectors of the State bodies may control. Things are likely to change in the future. Draft ministerial orders are said to be under preparation, fixing regulatory instantaneous concentrations.
Radioprotection
The Decree n° 66-450 of 6 June 1966, concerning the general principles of protection against ionizing radiation was amended by the Decree n° 2001-215 of 8 March 2001. The Decree transposed partially the Directive 96/29/Euratom of the Council of the European Union of 13 May 1996, laying down Basic Safety Standards for the protection of the health of workers and the general public against the dangers arising from ionizing radiation, nearly one year after the deadline for transposition into national legislation.
In compliance with the European Directive, Article 17 of the Decree of 1966 was modified to take into consideration the new annual maximum dose limit of 1 mSv for individuals (down from 5 mSv).
The transposition of the Directive has had important implications on French radioprotection legislation. Not only did France have to rewrite part of its health and work regulation, it also has to take into consideration new principles introduced by the Directive, such as the justification principle. This principle may be applied to new as well as to existing classes or types of practice which may be reviewed as to justification whenever new and important evidence about their efficacy or consequences is acquired.
Responsibility is left to individual Member States to ensure compliance with the basic safety standards and the Commission would intervene only if it thought that Member States were not exercising those responsibilities. This and the ALARA (as low as reasonably achievable) principle, also provided for in the Directive, will in all likelihood have considerable consequences on the French present authorisation system for radioprotection.
It is worth noting that to lighten the legislative procedural system, the French Parliament passed a law on 3 January 2001 providing for the transposition of a number of European Directives through simple parliamentary ordinances. Interestingly enough, the Directive 96/29/Euratom was discretely transposed through a governmental Decree in March 2001, either to avoid a public debate on the matter or to keep the decision centralised and under the control of the executive power.
References to International Legislation
Except for radioprotection and the transposition of European directives and specific multinational treaties, French regulation concerning the discharges of radioactive effluents hardly or ever mentions international legislation, conventions or recommendations. Several international agreements today call for more stringent national regulations aimed at reducing if not eliminating discharges of radioactive effluents, especially releases into the sea.
Because most of them are legally non-binding, the French Administration has had a rather contemptuous attitude towards the results of such milestone international conventions.
The London Dumping Convention recognises that the capacity of the sea to assimilate wastes and render them harmless, and its ability to regenerate natural resources, is not unlimited and that Member States must promote the effective control of all sources of pollution of the marine environment, including radioactive pollutants.
Within the framework of the Convention for the Protection of the Marine Environment of the North-east Atlantic, the OSPAR Commission called its Member States in 1998 to work towards achieving substantial reductions or elimination of discharges, emissions and losses of radioactive substances. The OSPAR Decision 2000/1, which entered into force on 16 January 2001, even calls for reviewing the authorisations of discharges.
Operation at La Hague
Reprocessing at La Hague
The first reprocessing plant at La Hague, the UP2-400 plant for gas graphite reactor fuel, was started in 1966 for civil and military purposes the investment was covered for one half by the military and for the other half by the civil budget of the Atomic Energy Commission CEA and operated until 1998, with about 9,350 tonnes being reprocessed. In 1990, UP-3 was brought into operation, and in 1994, UP2-800 as well. These two plants have reprocessed about 12,000 tonnes so far. Table 3 below shows the annual fuel throughputs at the three reprocessing plants in La Hague from 1966 to 2000. The cumulated total of spent fuel reprocessed at La Hague up to the end of 2000 was approximately 21,200 tonnes.
Table 3 Reprocessing History at La Hague Plants by Fuel Category, 1966-2000 (in tonnes)
YearUP2 (400) (1)UP2 (800)UP3UNGGLWRMOX / FBRLWRLWR196652.8196797.61968188.71969227.81970136.01971164.51972250.41973212.51974634.51975441.41976218.214.61977351.318.01978371.538.21979264.679.9Phenix 2.21980253.1104.9Phenix 1.51981250.0101.3Phenix 2.21982226.1153.51983117.0221.3Phenix 2.01984185.3255.1Phenix 2.11985109.3351.4198675.8332.6198768.2424.91988345.71989430.330.31990331.1194.61991311.1351.41992219.9German MOX 4.7448.21993353.8601.41994317.3258.6700.419950.0758.1800.6199612.4849.6818.919970.0849.6820.3199832.0EDF MOX 4.9774.8821.919990.0848.6712.92000810.3387.2TOTAL4,896.54,449.419.65,150.06,688.2(1) This doesnt include reprocessing of a small quantity of RNR fuel in AT1, which is part of UP2 of the INB n° 33, between 1969 and 1979.
Source: Various documents and personal communications, COGEMA, 1997-2000
Waste Production of La Hague
As shown in Tables 4 and 5, the reprocessing operations at La Hague produce significant quantities of wastes. Table 4 indicates the quantity of waste that would be produced annually from the reprocessing of one years spent fuel output from a 1,300 MWe PWR (around 30 tonnes); Table 5 shows annual quantities of conditioned and unconditioned reprocessing wastes s accumulating on the La Hague site. The year-to-year evolution of those stocks over the past 8 years is summarised in Annex 12.
Table 4 Annual Wastes Arising from Spent Fuel Reprocessing at La Hague of a 1 000 MWe PWR (1)
Conditioned waste for storageProcess wastesActivity (GBq/an)Conditioning materialsVolume (m3/year)Beta, gamma emittersAlpha emittersSolution of fission products555,106(2) 2,775,103Glass3Structural wastes (hulls and nozzles)74,1052,775Cement15Sludge from liquid effluents treatment37,1042,590Bitumen13Technological waste from zone 4 (3)< 37.103< 37.103Cement5 to 8Technological waste from zones 3-237.103NegligibleCement35 to 45(1) One 1,000 MWe PWR discharges around 30 t of spent fuel annually.
(2) Of which 99.5% of transuranians (less than 0.5% of plutonium).
(3) Zones 4, 3 and 2 are corresponding to a decreasing potential risk of radioactive dissemination.
Source: COGEMA.
Table 5 Waste Inventory at La Hague, Quantities and Volumes (as of the end of 1999)
Waste inventoryVolume (1)As of
31.12.1999Evolution
1998-1999As of
31.12.1999Evolution
1998-1999Cumulated amount of spent fuel reprocessed (tons)15,097.2+ 1,561.5Conditioned wastesBituminised waste (drum)9,898+ 932,355+ 22Hulls and nozzles (drum) (2)4,249+ 5917,435+ 1,034Cemented technological waste (drums)4,311- 2524,900+ 285Waste contaminated with alpha emitters (drum) (3)3,958- 405495- 50Canisters of vitrified waste6,759+ 4681,325+ 91.7Unconditioned wastesHulls, nozzles, and other ILW (tons)2,245.4- 8.82,600- 10Magnesium, graphite and metal (m3)3,058.8- 83,058.8- 8Sludge (m3)9,288.0+ 249,288+ 24Storage resin (tons)34.4- 0,3??????Nympheas resins cartridges (tons)30.5- 28.1??????Graphite resins (m3)319.003190Low contaminated soil, sludge and metal (m3)14,500.0+ 8014,500+ 80(1) Calculation of volumes by WISE-Paris where not indicated in the inventory colon.
(2) On the total of 4,249 drums of conditioned hulls/nozzles, 2,731 drums (4,780 m3) are to be re-conditioned in the future compacting ACC workshop (planned for 2001).
(3) Some of these wastes are planned to be re-conditionned.
Source: National Inventories of Radioactive Wastes, ANDRA, 1999-2000
Low Level Waste (LLW)
Low Level Waste (LLW) in France is radioactive waste with a total activity of less than 3,700 Bq/g and a content of alpha emitters of less than 370 Bq/g. LLW stemming from the contamination of materials used for reprocessing at La Hague has been sent from 1969 to 1994 to the neighbouring final disposal site Centre de la Manche (CSM). During this period, the CSM accepted 1,470,000 containers (527,000 m3) of low and intermediate level waste issued from reprocessing of French and foreign spent fuel. After the CSM closure in 1994, LLW from La Hague has been sent to a new final disposal site, the CSA (Centre de stockage de lAube) in the east of France.
Intermediate Level Waste (ILW)
Intermediate Level Waste (ILW) in France is radioactive waste with a total activity of less than 370,000 Bq/g. It is essentially sludge issued from the Effluents Treatment Stations (STE2 and STE3) and hulls and nozzles from the sheared fuel assemblies. Sludge has been conditioned under a bitumised form until 1997 and COGEMA is now developing another conditioning technology for this waste. Hulls and nozzles have been compacted and cemented in containers.
There is no national repository in France for these wastes which are temporarily stored on the La Hague site (STE3 building for bitumised waste and EDS and E/D EDS buildings for cemented waste). As of the end of 1999, 4,249 packages of hulls and nozzles and 9,898 packages of bitumised waste were in storage on the La Hague site. Moreover, 9,288 m3 (or 39,000 containers equivalent) of sludge have been stored as raw waste and 2,076 m3 of hulls and nozzles (together with 540 m3 of some other waste) have been waiting for more than six years to be conditioned. In 1990, the IPSN (Institute for Nuclear Safety) wrote already that it: considers that the re-conditioning of sludge contained in the storage silos of STE2 is of high priority due to the risks of contamination of the water table.
High Level Waste (HLW)
High Level Waste (HLW) is radioactive waste from the dissolution of the fuel in nitric acid and recovered after separation of the different radionuclides. The glass logs in which they are immobilised in the R7 (for UP2-800) and T7 (for UP3) facilities of La Hague, contain essentially fission products and minor actinides, or around 99% of the radioactivity of the spent fuel reprocessed. Production rate of HLW at La Hague is around 200 m3/year (around 130 m3for 1,000 tons of spent fuel reprocessed). As of the end of 1999, a total of 6,759 canisters of vitrified waste were stored in the R7, T7 and NPH facilities of the La Hague site and 608 canisters had been returned to foreign clients as of March 2001.
Curie-swap
If most of the La Hague foreign reprocessing contracts include return clauses for radioactive waste, they do not include clauses concerning specific categories of waste. To simplify the waste management, COGEMA and its foreign clients agreed to interpret the contract clauses in terms of radioactivity content and not in terms of volume, i.e. they preferred to return smaller volumes of waste with higher radioactivity content over return of waste corresponding to the volumes generated by the reprocessing of foreign fuel. This interpretation of the return clauses leads to the management of huge volumes of foreign intermediate level waste at La Hague and management by ANDRA of the low level waste issued from the reprocessing of foreign fuels at La Hague. The case of foreign waste storage in France is illustrated in Annex 13.
Reprocessing at La Hague and HLW long-term management
As in nuclear countries that have chosen the direct disposal option for spent fuel, decisions on definitive solutions for HLW management are yet to be taken in France, as shown in Table 6.
Table 6 Waste Management in France by Category (as of the end of 2000)
Short lived
main elements < 30 yearsLong Lived
> 30 yearsVery Low Level WasteCurrent studies for
application at CSAStudies on management of mining tailingsLow Level WasteSurface storage (CSA)
Studies on management of tritium contaminated wasteStudies (radium, graphite)Intermediate Level WasteHigh Level WasteResearch and Laboratory Site Investigations
(under the law of 30 December 1991)Source: DSIN, 2001
Only recently, as pointed out in a parliamentary report [Bataille, 2001], it was admitted that some French spent fuel, both uranium fuel and MOX, would also go to final disposal. Final waste volumes to be managed are unfavorable to the reprocessing route also because of the much higher heat output of spent MOX if compared to uranium fuel [Charpin et al, 2000]. Spent MOX fuel requires a longer interim storage before its final disposal some 150 years instead of 50 years for uranium fuel.
Discharges from La Hague
La Hague discharges are set out in Figures 8 and 9. Note logarithmic scales are used in these illustrations in order to deal with the wide range of data points.
Authorisations
The La Hague site is authorised to release a significantly higher quantity of radionuclides both in marine media and in the atmosphere than any other nuclear facility in France. Annex 14 presents a comparison between the reprocessing plant authorisations at La Hague and two typical French light water reactor sites. The comparison of the authorised release levels at La Hague and a Flamanville reactor, 17 km along the seashore from the La Hague site shows that the La Hague limits are roughly:
- 20,000 times higher for gases, excluding tritium (krypton 85, carbon 14
),
- 1,000 times higher for gaseous and liquid tritium,
- 275 times higher for halogenes (iodine, chlorine, etc)
- 8,000 times higher for liquid beta emitters, excluding tritium, discharge.
No specific limit exists at La Hague concerning the atmospheric release of alpha emitters while they are prohibited at EDF power plants. Discharges of alpha emitters into water are also prohibited at EDF plants.
Figure 8 Annual Air Emissions from La Hague (in TBq)
EMBED Excel.Sheet.8
Source: COGEMA [1998], Dossier dEnquête Publique
Figure 9 Annual Liquid Discharges from La Hague (in TBq)
EMBED Excel.Sheet.8
Source: COGEMA [1998], Dossier dEnquête Publique
Figure 10 Evolution of La Hague gaseous discharges 1990-1999 (index 100 in 1990)
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Source: [GRNC, GT-1, 1999]; communication COGEMA, 2001
Figure 11 Evolution of La Hague liquid discharges 1990-1999 (index 100 in 1990)
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Source: [GRNC, GT-1, 1999]; communication COGEMA, 2001
Discharge levels of major radionuclides
Nuclide releases from La Hague are several orders of magnitude higher than those from French power reactors (see Annex 15). In 1999, La Hague released over 7,000 times more radioactivity into the environment than the two light water reactors 17 km along the seashore from the La Hague site.
The UP2-800 plant began to operate in 1994 and the tonnage of fuel reprocessed at UP2 increased by a factor of four within 10 years. The graphs presented in Figures 10 and 11 for major radionuclides illustrate the increased discharges since 1994, in correlation with the increasing production.
Krypton 85 (85Kr, half-life: 10.7 years) releases have been increased five fold over the last decade, in line with the tonnage throughput.
Carbon 14 and tritium gaseous releases have been increased by a factor of four and three respectively, in the period 1990-1999. These nuclides exchange easily with carbon and hydrogen atoms in living organisms. Carbon and hydrogen, of course, are major constituents of organic matter and hydrogen is a major constituent of water. Gaseous releases of these nuclides have been increasing since the beginning of La Hague operations, and reached a maximum in 1996 for the 1966-1996 period.
COGEMA does not report measurements for gaseous chlorine 36 (36Cl, half-life of 300,000 years), gaseous technetium-99 (99Tc, 214,000 years) and gaseous strontium 90 (90Sr, 28.8 years) releases.
There is a trend towards lower marine discharges of some radionuclides from La Hague (see Figure 12) and marine discharges of technetium 99 exhibit a sharp decrease since 1990 with the phase out of the reprocessing of gas-graphite fuel. However marine discharges of most long-lived radionuclides have increased, in some cases significantly: e.g. iodine 129, chlorine 36, and carbon 14.
Figure 12 Evolution of La Hague plutonium, strontium-90 and caesium-137 liquid discharges 19901999 (index 100 in 1990)
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Source: [GRNC, GT-1, 1999]; communication COGEMA, 2001
Discharge trends
The direct relationship between reprocessing throughput and nuclide discharges at La Hague means that, under current technical conditions, emissions will not decrease without a decline in reprocessing activity. On the contrary, the future conditioning of the large stocks of raw intermediate level wastes might lead to additional radionuclide releases.
Unplanned Radioactive Releases
Major accidents and list of incidents at La Hague plant
There have been numerous incidents and accidents at the La Hague plants. Annexes 16 and 17 give an overview of a number of examples. Some accidents have led to the release of significant quantities of radioactivity to the environment, in some cases by a factor of 10 or more in excess of the annual limits. In a few cases, doses delivered to workers and/or members of the public have been substantial. For example, as a consequence of a severe discharge pipe break in 1980, individuals of the critical group (fishermen) received approximately 3.5 times the currently authorised annual dose (namely 3,486 mSv, to be compared with the current European limit of 1 mSv/year).
In many cases, a proper evaluation of environmental and health consequences were not carried out at all. However, accidents/incidents are estimated to be responsible of 36% of the leukaemia risk level for the 0-24 year age category around the La Hague site, according to the Radio-ecological Group of North-Cotentin [GRNC, GT4, 1999].
Potential Hazards at the La Hague plant
Neither COGEMA nor any governmental institution in France has published a thorough global risk analysis for the La Hague plant.
The main consequences of hazards likely to be induced at La Hague are:
-public and workers exposure to radiation or to chemical matters during operations,
-dispersion of radioactive materials or chemical products in the environment,
-fires and explosions giving rise to public or workers exposure.
The main sources of potential hazards are listed below:
Fire and explosions. There is a serious risk of fires and explosions in the storage pools, in the vitrification plants or in the effluent treatment plants at La Hague. The Annex 18 lists the main fires or explosions occurred in the reprocessing plants around the world. A loss of coolant in storage pools could lead to a self-sustained fire that would release large amounts of radionuclides into the environment.
Caesium-137 (137Cs, half-life 30 years) stocks in the spent fuel pools of La Hague. One ton of reference spent light water reactor (LWR) fuel contains just above 1 kg, or 3.25 103 TBq of caesium 137. COGEMA is expected to soon be authorised to enhance the capacity of storage of the pools to 17,600 tons of spent fuel. Considering that 7,508 tHM of different spent fuels are currently stored in La Hague cooling ponds (as of 31 May 2001), the caesium 137 stock in La Hague ponds could be close to 7.58 t, that is 287 times the quantity released by the Chernobyl accident (26.4 kg). The accidental release of the total quantity of caesium 137 stored at La Hague in the marine environment, according to a report commissioned by the European Commission [Dreicer, 1995], would lead to a dramatic regional collective dose of 2 million man.Sv, that would mean an expected 100,000 fatal cancers, according to ICRP risk factors (5% per man.Sv). More calculations of collective doses are presented in Annex 19.
Separated plutonium stocks at La Hague. Potential risks of dispersion of some of the 50 tons of separate plutonium currently stored at La Hague are not analysed by COGEMA in the public inquiry report. These stocks raise concern for nuclear proliferation since plutonium is a key ingredient for nuclear explosive devices. Several kilograms are sufficient to manufacture a crude nuclear device.
Environmental Concentrations and Doses
Environmental Concentrations
Radionuclide concentrations in foodstuffs that exceed the EU Community Food Intervention Levels (CFILs) have been only rarely identified in the La Hague environment. Royal crabs caught in the area of the sea discharge point of the La Hague plant were measured in 1997 with strontium 90 concentrations and plutonium exceeding the CFIL respectively by a factor of eight and two (see Annex 9b for details).
However, only selective samples have been taken until recently and very few radionuclides have been measured before 1990. No measurements at all are available for key isotopes such as carbon 14, or krypton 85 before 1996. Serious efforts to begin completing the range of measured isotopes have started only in 1996/1997. Also, the full range of samples has not been taken systematically every year, but sometimes only as spot checks with very few sites fully sampled. This lead to incomplete series of data and orphan sites, both very difficult or impossible to interpret. Sampling redundancy is very low and the few redundant samples sometimes differ in concentrations by a factor of two. This illustrates the absence of a coherent surveillance program of environmental contamination, especially before 1996.
Of the 500,000 measures conducted between 1978 and 1997 and inventoried by the GRNC, 51% have been carried out by the operator COGEMA, 16% by the national marines department GEA (Marine Nationale Groupe dÉtudes Atomiques), which operates a nuclear submarine base at Cherbourg and 17.5% by the national radiation protection board OPRI (Office de Protection contre les Rayonnements Ionisants) [GRNC, GT-2, 1999]. Given the very low share of samples analysed by other institutes (for example ACRO [1997], University of Bremen [1997]), it is worth noting that some of the highest readings were identified by these latter laboratories on some of the least measured radionuclides. This should be an additional incentive to enlarge the redundancy of measurements.
Given the absence of a systematic and coherent long-term sampling and measuring program, it is difficult to carry out a trend analysis of nuclide concentrations in the environment due to the La Hague reprocessing activities. The following historical overview of the La Hague area contamination (Table 7) should therefore be read as a tentative partial analysis only that also illustrates the lack of continuous data series.
Table 7 Overview of peak years of nuclide concentrations in the La Hague environment
Sample type137Cs, 60Co, 125Sb, 106Ru/106Rh, 40K90Sr3H131I99TcFucus1979/801984/85???1985Limpets, mussels, oysters1980/811985/86????Drinking water1979/80No peak?1981/82??Grass1980/81No peak????Milk1980/811985/86198419821985/86?Fishes1982/831987/881984???Source: WISE-Paris, 2001, from [GRNC, GT-2, 1999]
Concentration peaks in 1979/1980 vary in intensity depending on the sampling area, the sample type and the measured radionuclide, but reduction factors between 10 and 50 if compared to 1997 levels can be retained. Reduction factors between 5 and 25 if compared to 1997 levels can be retained for the 1984/1985 contamination peaks. Since 1990, measures of contamination seem to indicate a slight but regular decrease of radionuclide concentrations where measured.
The sharp increase in releases of some radionuclides from La Hague to the sea (in particular tritium and iodine 129) and the air (in particular tritium and carbon 14) throughout the 1990s is not really reflected in the trend analysis because of lacking data. The GRNC conclusions about both carbon 14 and iodine 129 concentrations is that there are not enough data to evaluate the representativity and dispersion of the values [GRNC, GT-2, 1999]. However, the GRNC concluded for carbon 14 that the results of measures in the marine or terrestrial environment superior to 250 Bq/kg show recent anthropogenic contribution. It also noted an increase of iodine 129 concentrations in fucus since 1988.
Doses from Environmental Radiation
While the official figures have generally shown a very small dose impact from environmental radiation in the La Hague region (see Annex 27), the analysis of the potential impact of more highly contaminated food stuffs, which have rarely been published but have been identified occasionally near La Hague in the past (see previous point 6.4.1), gives a different picture, as illustrated by a study commissioned by the German Office for Radiation Protection (BFS) [Beninschke, 2000].
The Critical Group around La Hague, as defined by COGEMA [2000], the fishers from Goury, have a defined annual uptake (ingested activity for adults corresponding to the nominal discharges) of:
strontium 90: 8.6 Bq
technetium 99: 28 Bq
iodine 129: 44.7 Bq
caesium 137: 329 Bq
ruthenium 106: 4,816 Bq
tritium: 6,722 Bq
artificial carbon 14: 13,985 Bq
These are very small quantities of radionuclides if compared to concentrations found in the La Hague environment and foodstuffs. The supposed uptake of strontium 90, for example, would be already reached with the ingestion of 1.7 grams of crabs taken close to the discharge point of the liquid effluents. Moreover, the consumption of 320 g of those crabs are sufficient to reach the German dose limit for the red bone marrow. It is therefore plausible that parts of the local population around La Hague has been and is exposed to much higher doses than considered in the official dose estimates.
The cumulative effective dose (adult: 2.3 mSv/a; child: 0.83 mSv/a) induced by the consumption of seafood (especially relevant are the crabs from the vicinity of the discharge pipe), as calculated under German statutory dose assessment assumptions, exceed German and EU dose constraints (0.3 mSv/a and 1 mSv/a respectively).
Impact of La Hague Discharges Background Studies
Marine effects
Long range transport of long-lived radioelements can spread contamination beyond the European continent. The mean residence time of iodine in the atmosphere is 14 days, sufficient to allow contamination of the southern hemisphere, according to [Moran, 1998]. Moran also alleged that global tropospheric circulation could drive the air masses across the Atlantic and could result in transport of iodine 129 from European fuel reprocessing facilities to the continental US. After deposition, iodine 129 infiltrates the soil and is then washed into rivers and other surface bodies.
Water movements in seas adjacent to a source point of marine discharge allows long-lived radionuclides to be transported over long-range distances. Releases from Sellafield reach the Norwegian coast by ocean currents for instance, within two to three years. Higher transfer rates of soluble radionuclides from La Hague compared to Sellafield were observed and explained by a coastal current from the English Channel, along the European coast, to the Norway coastal areas. [Brown, 1998]
Discharges of iodine 129, technetium 99, carbon 14 concentrate in marine organisms and sediments. Some recommended values of the concentration factor in various marine organisms, provided by the Groupe Radioécologie Nord-Cotentin (GRNC), are compiled in Annex 20. Long-lived radionuclides such as iodine 129, technetium 99 exhibit the highest concentration factors in seaweed. Seaweed is for instance used in the food processing industry (in ice cream and milk-based products) and in the formulation of cosmetics. In the past, farmers spread seaweed on the soil as fertiliser and used it as animal feedstock. The French independent laboratory CRII-Rad. has stated that these possible transfer patterns should be included in the evaluation of global collective doses. The French National Evaluation Commission (CNE) on research into radioactive waste management [CNE, 2000] raised the specific problem of improving iodine-contaminated waste packaging. The increasing discharges of iodine 129 and tritium from La Hague reprocessing facilities appear to be in breach of Frances obligations under the OSPAR Convention.
Health Effects
Cancer morbidity inquiry in the Manche Department
In 1983, a 3 year epidemiological study by the Observatoire Régional de la Santé de Basse-Normandie determined the frequency and the distribution of cancer in the region [Collignon, 1983]. Morbidity was found to be higher than expected in the surroundings of Cherbourg for men in case of leukaemia and respiratory organs, and for women in case of leukaemia and lung cancer (see Annex 21). Moreover, mortality data show an increased rate of cancers for the digestive organs in North-Cotentin, and only Cherbourg county shows a mortality significantly higher than the regional mean value for men.
Epidemiological study by Viel and Pobel
In 1995, Viel et al published the results of a study of the incidence of leukaemia among persons aged 024 years living in a 35 km radius around the La Hague reprocessing plant [Viel, 1995]. This study suggested an excess of leukaemia cases in the canton of Beaumont-Hague (corresponding to about 10 km around the plant). Four cases were observed between 1978 and 1992, compared with 1.4 expected. In 1997, Pobel and Viel published the results of a case-control study, which they claimed provided convincing evidence in childhood leukaemia of a causal role for environmental radiation exposure from recreational activity on beaches.
Two kinds of behaviour were found to be potentially connected with the increase in leukaemia risk:
-the use of local beaches for recreational activities by children and mothers during gestation, and
-fish and shellfish consumption.
In the first case, the relative risk was found to be 2.87 (compared with 1.00 where children or mothers never went to the beach). Ingestion of seafood increased the relative risk to 2.66 (to be compared to 1.00 if no seafood was consumed).
Viels concluded that there is some convincing evidence in childhood leukaemia of a causal role for environmental radiation exposure from recreational activities on beaches [Pobel, 1997]. These findings resulted in the French Government ordering a new inquiry by the Radioecological Group of North-Cotentin (GRNC) to look into the leukaemia risks around La Hague.
The Radioecological Group of North-Cotentin (GRNC) survey
In 1997, the French Ministry of Land Use Planning and of the Environment and the Secretariat for Health and Social Security commissioned a study by the Nord-Cotentin Region which set up the Nord-Cotentin Radioecology Group (GRNC) for this purpose. The report of the Group in July 1999 [GRNC, 1999] concluded that the number of cases of radiation-induced leukaemia attributable to radiation doses from discharges from local nuclear facilities would be around 0.002. They stated that it seemed improbable that exposures due to discharges from local nuclear facilities would contribute significantly to explaining the elevated incidence of leukaemia observed among the young people aged 0-24 years in the canton of Beaumont-Hague over this period [Rommens et al, 2000].
This conclusion is similar to that reached in the UK concerning the increased leukaemia incidence in young children at Seascale near Sellafield. Also, as at Sellafield, important uncertainties exist over the estimation of radiation doses from environmental discharges. The GRNC report expressed reservations over whether conclusions could be drawn without a quantitative analysis of uncertainties; this analysis is now underway [see Simmonds, 2000].
The GRNC report stated that the contribution to doses from nuclear facilities was low, regarding the incidence of leukaemia showed by recent epidemiological studies. Nevertheless, the Group added: this result is a mean estimation and it is worth underlining that uncertainty margins were not quantified.
CRII-Rad Laboratory representatives, members of the GRNC, refused to sign on to the reports conclusions. Their main objections were [CRII-Rad, 1999]:
-the Group excluded investigations into collective doses and the long-term impacts of long-lived radionuclides (including carbon 14, iodine 129, technetium 99);
-high levels of contamination of marine life surrounding the discharge pipe were set apart although local fishing practices give rise to non-negligible exposures;
-only 0,23% of the measurements used in the study were carried out by independent laboratories, and 75% by the operator;
-exposures from radioactive transports was not taken into account: spent fuel is currently moved by train following usual routes, and the public can be exposed to non-negligible doses;
-involuntary transport of radioactive particles by workers to their home was not considered;
-possible evolution of human practices regarding diets and food hsabits was not explored , including possible increased seaweed consumption, and public use of the Sainte-Hélène contaminated stream;
-no analysis on a multi-factorial impact of possible synergistic effects (chemical discharges, non-ionising radiation
) was carried out;
-father exposures to ionising radiation before conception were not studied;
-mother exposures during gestation included routine but not uncontrolled releases of radioactivity (although the latter represent 36% of ex-utero exposures.
The GRNC did not use a collective dose model to assess both leukaemia risk and doses committed towards various reference groups.
In the case of leukaemia, the experts summed up the contribution of routine discharges for a 30 year operational period in terms of individual dose to the bone marrow (not to the whole body). Then, this individual dose was multiplied by, roughly, a definite number of persons, supposedly representative of the evolution of the population of the county between 1966 and 1996.
In the case of the dose evaluation, the GRNC used an individual dose approach that was applied to a reference group. The annual committed doses are presented in Annex 22. COGEMA dose estimates are under 10 micro Sievert (mðSv) per year for the two reference groups it has chosen. GRNC calculated an individual dose six times higher than the COGEMA values for four different reference groups (least case: 60 mðSv/year).
GRNC did not use a global model to assess leukaemia doses and risks. A global model that takes into account the earths population truncated at 100,000 years was developed by CEPN in its study for the European Commission [Dreicer, 1995]. This model reflects the collective and long term impact of longer lived radionuclides, than the 30 year estimate by GNRC. Given the 16 million year half-life of iodine-129, an untruncated dose model should really be used (i.e. extending doses to infinity).
La Hague Childhood Leukaemia Study 2001
In June 2001, a new epidemiological study extended the earlier Pobel study to include new data from 1992 to 1997 [Guizard, 2001]. In this period, 3 cases of acute lymphoblastic leukaemia were observed while 0.47 were expected.
The key findings were that the study confirmed the earlier findings by Viel and Pobel. The study also indicated that the increased incidence was continuing, and had not stopped. Most important, the study provided more data to allow statistical significance to be established (for the first time in France) for the increases in leukemias at La Hague.
The study indicates the predominance of acute lymphoblastic leukaemia over childhood leukaemia cases diagnosed in the Beaumont-Hague electoral ward. Although not conclusive, this observation could be linked to the dramatic intensity of population movement that occurred in this particular area.
The authors conclude: In view of statistically significant clusters of childhood leukaemia near other European nuclear reprocessing sites, and the concerns of the local population, these findings argue in favour of continued investigations in Nord Cotentin. Three lines should be followed: measuring the incidence of child leukaemia among people who have lived at any time in Beaumont-Hague; identifying possible causes of leukaemia in the area (studies of population movements); and measuring the incidence of other diseases the occurrence of which could be linked to radiation (other cancers, and reproductive function disorders).
Radiological impacts of spent nuclear fuel management options, NEA, 2000
The Nuclear Energy Agency began in 1995 a comparative assessment between two fuel cycle options, at the request of the OSPAR Commission. This study aimed at comparing from the standpoint of the radiological impact the reprocessing activities and a once-through fuel cycle where spent fuel is not reprocessed.
According to the NEA study, both public and workers exposures could be reduced by about 20% through reprocessing. The report assumes that MOX fuel use avoids extraction of natural uranium in this proportion. However, this is a highly theoretical assumption that has been contradicted by various other sources. A report to French Prime Minister presented in mid2000 [Charpin et al, 2000] indicates that the uranium savings of the plutonium path do not exceed 8%. However, reprocessing operations clearly add a higher collective dose, mainly towards the public.
The NEA Report concludes that the differences between the two fuel cycles examined options are small from the standpoint of radiological impact. In this connection, it is simply not justifiable to draw definitive conclusions (
). Consequently, radiological impact is not a key factor favouring one option or the other.
However this conclusion is contradicted by a number of independent studies [Sumner, 1992; Fairlie, 1997], which found that doses from reprocessing considerably exceeded those from dry storage routes, sometimes by three or four orders of magnitude. Even from cursory examination, it is clear that doses from large discharges of nuclides from reprocessing will exceed the very low doses from dry stores.
And in fact, that is not put into question by the NEA study, as OSPAR Resolution 2000/1 from June 2000 points out: Noting further that the NEA study has demonstrated that implementing the non-reprocessing option (dry storage) for spent fuel would eliminate the discharges and emissions of radioactive substances that currently arise from reprocessing it.
Uncertainties in Dose Assessments
A Mandate for the Radio-ecological Group of North-Cotentin to Assess Scientific Uncertainties
Many uncertainties exist in the assessment of doses from discharged nuclides. For example, as regards nuclide inventories, Task Group n°1 of the Radioecological Group of North-Cotentin (GRNC) has stated that it was difficult to thoroughly quantify or even to estimate the activity of the radionuclides discharged because of their various behaviours, depending on the step in the process and because the efficiency of the cleaning treatment of the effluents is not known with high precision for each radionuclide. (GRNC, 1999) Moreover, estimates are made when measurements are unavailable.
As regards final doses, GRNC Task Group n°4 stated that the different steps leading to risk assessment required many hypotheses and approximations that imply an uncertainty surrounding the final results, which is difficult to quantify. (
) It is worth underlining that the uncertainty margins were not quantified. The GRNC is presently carrying out a sensitivity and uncertainty analysis of the main parameters associated with the leukaemia risk in Nord-Cotentin. So far, it has identified no fewer than 4,000 parameters, including 200 critical parameters, in the methodology used to assess dose impact. A final report is expected to be published later in 2001.
Sources of Uncertainties
Computer codes
Several computer codes exist to determine radionuclide activities in spent fuel. According to J.C. Zerbib, senior consultant to the French CEA and a member of the Task Group n°1 of the GRNC, these codes have an error margin of about 5% (up to 10% for some radionuclides). In the case of iodine 129, literature figures range from 170 to 230 grams per ton of spent fuel (a difference of 30%). The lack of an international consensus on these values could result in significantly under-estimated releases.
Paucity of measurements and environmental monitoring
The CRII-Rad Laboratory has drawn attention to the lack of environmental measurements by the regulatory bodies IPSN and OPRI for many radionuclides [CRII-Rad, 1999]. For instance, technetium 99 and plutonium 241 so far has not been measured in marine organisms by OPRI. No measurements are currently carried out in the vicinity of the discharge pipe by IPSN, and no measurements at all are carried out by the European Commission under Article 35 verification rights.
75% of the measurements available in [GRNC, 1999] were provided by operators which suggests a lack of independent environment monitoring around the La Hague plant. A telling criticism was voiced by a member of the GRNC in the conclusions of the Groups report: up to now, measurements were conducted only to check the correct operation of the installations and not in order to monitor health effects on populations.
Disputed measurements
Some local practices of fishermen around the discharge pipe have been ignored although of considerable impact on the local population (some hundreds of microsieverts, to be compared with the committed doses of the GRNC scenarios, see Annex 22). Furthermore, M. Guillemette contested measurements by COGEMA in molluscs at the moment of the discharge pipe incident in 1979. As a consequence, the president of the GRNC created a new group of experts that has been focusing for six months on this issue. The impact of the incident was assessed again and the individual dose for a fisherman rose from 0.874 mSv (before rectification) to 3.486 mSv, i.e a four-fold increase. The annual EU limit is 1 mSv for an individual of the public.
Lack of transparency inside the facilities of COGEMA
Since 1999, OPRI has checked COGEMA measurements of marine or gaseous effluents, in a more regular manner. The technical service of the safety authority, the IPSN, also assesses radionuclide concentrations inside the plant on the basis of the operator data, during modifications or the commissioning of a new facility. But all these data are kept confidential.
WISE-Paris studied the very long-lived nuclide, iodine 129 (129I, half-life: 15.7 million years). Using two models (those of COGEMA and UNSCEAR) and values recorded by COGEMA, WISE-Paris quantified the differences between the theoretical iodine 129 activity in spent fuel and the discharged activity to sea or air. Annex 24 compiles the results of these calculations from 1989 to 1999. Large gaps are observed in the beginning of the 1990s, as only 50% of the theoretical values were reported discharged.
The president of the GRNC has agreed that the iodine 129 problem was important enough to justify the creation of a working group under the responsibility of GRNC. Correspondence with Dr. Sugier is presented in Annex 25.
WISE-Paris has assessed the individual dose committed by an accidental release of the non-attributed activity for the year 1997 (least case using the UNSCEAR code). We have assumed that all the activity was released either by the atmospheric pathway (uptake by inhalation) or by the marine pathway (uptake by ingestion of seafood). In both cases, the additional committed individual doses reach half of the annual dose that COGEMA alleges to be induced by all radionuclides to anyone of the reference group. The committed collective dose from non-attributed iodine 129 in the period 1989- 1999 would be about 2,500 manSv, about the magnitude of a serious nuclear accident such as the Windscale fire or the Kyshtym waste explosion in 1957 (for details of the calculation and references see Annex 25).
Comparative and Cumulative Analysis
Comparison of Releases in 1999 from La Hague and Sellafield
Figure 13 indicates that in 1999 (a representative year) discharges from La Hague and Sellafield were broadly comparable, except for technetium 99 discharges. In general terms, La Hague discharges were marginally greater than those from Sellafield, except for tritium air emissions, iodine 129 air emissions and technetium 99 liquid discharges. These differences are partly due to the higher fuel throughput at La Hague compared to Sellafield in 1999.
Figure 13 Discharges in 1999 from Sellafield and La Hague (TBq, Logarithmic Scale)
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Source: BNFL, 2000; COGEMA, 2001
With Sellafield, discharges have tended to follow the fluctuating fortunes of the sites reprocessing facilities.
In earlier years, it is likely that discharge data was estimated from operating data, i.e. fuel throughputs and burn-ups, as older measuring equipment was often incapable of detecting and/or measuring many radionuclides, including weak beta emitters. Particular difficulties existed with detecting iodine 129 levels given its low specific activity, low concentrations and weak decay energy. In many cases, environmental levels were below the Lower Limits of Detection (LLD) of measurement instruments.
In the case of Sellafield, in the late 1970s, efforts were clearly made to reduce the high levels of nuclide discharges and these were successful in the case of SIXEP and partly successful in the case of EARP. However high radionuclide concentrations from past discharges remain in the environment especially near Sellafield. As will be discussed below, total doses to critical groups near Sellafield are dominated by radiation (>75% of total dose) received from historic discharges rather than current discharges.
Key Nuclides for Collective Dose Calculation
Carbon-14
Although carbon 14 discharged from reprocessing is distributed globally, there are significant local increases in concentration. For example, Begg et al [1991] have reported that carbon 14 discharged from Sellafield has resulted in an approximate doubling of current ambient concentrations in the Irish Sea. In 1998 and 1999, carbon 14 levels in botanic plants near La Hague as measured by OPRI and COGEMA were 500 to 2,000 Bq/kg (c.f. natural background levels of 250 Bq/kg). Guillemette [2000] states that a level of 2,000 Bq/kg in humans corresponds to an annual dose of about 130 µSv, of which 115 µSv would be due to La Hague carbon 14 discharges. This is an appreciable fraction of the 300 µSv dose constraint usually applied to critical group doses.
Different approaches exist to carbon 14 management at reprocessing plants. For example, the Rokkasho-mura plant under construction in Japan is designed to remove most carbon 14 to atmosphere. At Sellafield, about 27% [Environment Agency, 2001] of carbon 14 arisings are removed in a caustic soda washing column, precipitated as a solid (barium carbonate), then encapsulated in cement [BNFL, 1993b]. COGEMA, which currently releases all carbon 14 arisings from reprocessing, recently stated that carbon 14 abatement was not cost effective in their view [COGEMA, 1999a].
Krypton-85
In 1989, the global inventory of krypton 85 was estimated to be about 3,300 PBq (i.e. 3,300 x 1015 Bq) nearly all from reprocessing plants [Kollert and Butzin, 1989]. Since 1989, this will have decayed by about half, but since then a further 2,000 PBq have been discharged from La Hague and 1,000 PBq from Sellafield.
A more precautionary approach to krypton 85 has been adopted in the United States. An NCRP [1975] Report concluded
prudence would seem to dictate that fuel reprocessing plants be equipped with krypton 85 removal systems as soon as the technology is practicable. Since 1983, US regulations have limited releases of krypton 85 to a maximum of 1,850 TBq per 1,000 MW electricity produced, a ten fold reduction from previous practice at the time [NCRP, 1980]. Diethorn and Stockho [1972] from the Nuclear Engineering Department of Pennsylvania State University concluded that
although the dose from krypton 85 is small,
there seems to be little justification for continuing the present world-wide practice of dumping it into the atmosphere (
) the only solution for krypton 85 is permanent storage. Eisenbud [1987] has stated if... fuel is reprocessed, 90% of the krypton 85 must be removed for extended storage until the gas has decayed sufficiently for release.
Iodine-129
Iodine 129 discharges from La Hague during 1975-1992 are estimated to be about 632 kg, and from Sellafield during 1967-1992 about 608 kg: the total from the two plants up to 1992 is therefore about 1.2 tonnes. This is 10 times larger than the total iodine 129 present in the oceans before the nuclear era, approximately 25 times that released by nuclear weapons testing, and several hundred times that released by Chernobyl. [Raisbeck et al, 1995]
In the period from 1993-1998, a further 1.4 tonnes of iodine 129 were discharged from La Hague and 0.36 tonnes from Sellafield, i.e. discharges in the 6 years after 1992 were more than in the previous 25 years. Iodine 129 discharged from La Hague and Sellafield in 1999 was eight times greater than the total iodine 129 released by the total fallout from all weapons testing.
In comparison, annual reprocessing emissions of caesium-137 and strontium 90 were never larger than 1% of cumulative nuclear weapons fallout.
Most La Hague discharges follow sea currents through the English channel to the North Sea, and Sellafield discharges flow mostly north around the Scottish coastline then also into the North Sea. Iodine 129 transit time from La Hague to the Norwegian coast is about 3-4 years. Iodine 129 discharges from both Sellafield and La Hague have risen over the past decade by a factor of about five.
Collective Doses from Reprocessing Releases
Collective Doses from Reprocessing
The process of reprocessing results in large-scale releases of long-lived nuclides, which are mobile and are distributed throughout Europe and the world. These nuclides include tritium, carbon 14, chlorine 36, krypton 85, technetium 99 and iodine 129. The European Commission has constructed models, which estimate doses to the UK, Europe and the world from distributions of carbon 14, tritium and iodine 129 nuclides. A rudimentary model also exists for krypton 85, which is assumed to remain a gas and not to interact with the biosphere, lithosphere and hydrosphere. No models yet exist for the global transport of chlorine 36 and technetium 99 although it is understood that the UK NRPB is presently considering a model for technetium 99. Little data exist for the source term of chlorine 36 in spent fuel, and its subsequent environmental transport. This is a subject for future research.
The following tables present European (8a and b) and global (9a and b) collective doses from tritum, carbon 14, krypton 85 and iodine 129 releases in 1999. These have been estimated simply by applying Person Sv/TBq conversion factors to TBq discharges from Sellafield and La Hague in 1999. Relevant conversion factors were obtained from [Simmonds, 1996] and [Mayall, 1993].
Totals are rounded to two significant figures, as global and regional models use parameters whose values are correct only to two significant figures.
European Doses
Table 8a European Collective Doses from 1999 Discharges at Sellafield
NuclideDose Coefficient
(Person Sv/TBq)Sellafield Releases
(TBq)European Dose
(Person Sv)Carbon-14Aerial7.972.923Liquid8.335.848Iodine-129Aerial107.40.00250.3Liquid4810.48230Krypton-85Aerial0.000037100,0003.7TritiumAerial0.00166221Liquid0.00000371,8000.007Total300Table 8b European Collective Doses from 1999 Discharges at La Hague
NuclideDose Coefficient
(Person Sv/TBq)La Hague Releases
(TBq)European Dose
(Person Sv)Carbon-14Aerial7.9719150Liquid8.331083Iodine-129Aerial107.40.00740.8Liquid4811.83880Krypton-85Aerial0.000037300,00011TritiumAerial0.0016800.13Liquid0.000003712,9000.05Total1,100
Global Doses
Table 9a Global Collective Doses from 1999 Discharges at Sellafield
NuclideDose Coefficient
(Person Sv/TBq)Sellafield Releases
(TBq)Global Dose
(Person Sv)Carbon-14Aerial1152.9330Liquid1155.8670Iodine-129Aerial9,4540.002524Liquid6900.48330Krypton-85Aerial0.004100,000400TritiumAerial0.0026221.2Liquid0.000041,8000.07Total1,800Table 9b Global Collective Doses from 1999 Discharges at La Hague
NuclideDose Coefficient
(Person Sv/TBq)La Hague Releases
(TBq)Global Dose
(Person Sv)Carbon-14Aerial115192,180Liquid115101,150Iodine-129Aerial9,4540.007470Liquid6901.831,260Krypton-85Aerial0.004300,0001,200TritiumAerial0.002800.16Liquid0.0000412,9000.52Total5,900Until recently it had been assumed that collective doses from tritium, carbon 14, krypton 85 and iodine 129 would constitute over 99% of total Regional/Global collective doses from all nuclides released. It is now understood that technetium 99 will also become globally distributed and will add to Regional/Global collective doses. Although no global model has yet been constructed for technetium 99, preliminary estimates by Fairlie and Sumner [2001] indicate that the global untruncated dose from the 70 TBq of technetium 99 released from Sellafield in 1999 might add about 700 person Sv to the total global dose from Sellafield releases, and about 4 person Sv to the European dose. Technetium 99 releases from La Hague are relatively low.
Commentary on Collective Doses from Sellafield and La Hague
The previous tables indicate that, each year, the Sellafield and La Hague reprocessing plants release nuclides that result in a collective dose to Europes population (600 millions) of approximately 1,400 person Sv. Expressed in global terms, each year, the two plants release nuclides which result in a collective dose to the worlds population (6 billion) of approximately 7,700 person Sv. These doses will be delivered gradually over many millennia to future generations throughout Europe/the world.
As discussed in Annex 6, many uncertainties exist over whether these doses will actually occur in the absolute sense. Nevertheless, given the information available to us today and given currently accepted models of radiation effects, these are the best estimates available to us of future radiological detriment from reprocessing releases at the two sites.
Use in Comparative Studies
Because of these uncertainties, it is recommended that the European Parliament should consider collective dose estimates in a relative, rather than absolute, sense. In other words, these estimates should be used as a tool to make comparisons with collective doses from other processes, in order to inform decision-making and policy. The UK NRPBs Board Statement on Radiological Protection Objectives for the Land-based Disposal of Solid Radioactive Wastes [NRPB 1992] has stated (paragraph 73) that comparisons of collective doses from different options were more reliable than absolute values. For example, it stated that collective dose estimates may be used in design studies of planned repositories to compare different options.
Table 10 Global Collective Doses From Anthropogenic Radiation Sources
Source of ExposureGlobal collective dose (Person Sv)Chernobyl Accident600,000World Nuclear Power Production to 1989400,000World Radioisotope Production and Use to 198980,000World Nuclear Weapons Fabrication to 198960,000La Hague Reprocessing for 10 years(1)~ 59,000Sellafield Reprocesing for 10 years(2)~ 18,000Kyshtym Accident USSR 19572,500Windscale Accident UK 19732,000World Underground Nuclear Testing to 1989200Three Mile Island Accident US 197940(1) Estimated from 5,900 person Sv/year x 10 years
(2) Estimated from 1,800 person Sv/year x 10 years
Source: Bennett, 1995; UNSCEAR, 1993
Similarly with reprocessing, collective doses from discharges may be compared with collective dose estimates from other nuclear-related activities. For example, the European collective doses of 300 person Sv (from Sellafield) and 1,100 person Sv (from La Hague) may be compared with the reference level for releases from Swedish nuclear reactors of 5 person Sv per GWyear capacity.
Other comparisons are made in Table 10 which ranks collective doses from other nuclear processes/accidents with collective doses from 10 years discharges from Sellafield and La Hague, using figures from the latest available year, 1999. Future life expectancies of these plants is understood to be at least 10 years, based on information from internal industry sources.
Use in Cost/Benefit Studies
To compare costs and benefits of options which have no common comparator (e.g. to compare the costs of new abatement facilities with the discharges they may save), collective dose estimates may be converted to fatalities using the conventional ICRP radiation risk factor of 5% per person Sv, and fatalities may be converted to £, $ or ¬ values using monetary values per statistical life. The two costs may then be compared as occurs in conventional Cost-Benefit Analysis techniques. Conventionally, this procedure is shortened to adopting a £, $ or ¬ value per person Sv saved. Unfortunately the range of values of a person Sv is wide and has been reported as extending from £20,000/person Sv in 1988 prices to £100,000/person Sv in 1990 prices.
The UK Department of Transport value of £700,000 per life has been used in cost benefit analyses in road traffic studies. It is equivalent to a person Sv value of £35,000 using a fatal cancer risk of 5% per Sv. In 1995, the European Commission used a value of £2 million (US $3 million) in its statistical valuation of a life for the external costs of fuel cycles, equivalent to a person Sv value of £100,000 [CEC, 1995]. Indeed, the latter figure is used by BNFL to reflect statistical risk and corporate profile [Robb, 1990]. These figures are set out in Table 11.
Table 11 Values of Person Sv
AgencyYearValue Of Statistical Life (£)Value Of Person Sv (£)UK NRPB 1991 20,000UK Dept of Transport 1992700,000 35,000BNFL 1991100,000European Commission 19952,000,000100,000US NRC 1995133,000Sources: [CSERGE, 1992; Robb and Croft, 1990; UK Department of Transport, 1992; Robb, 1994; CEC, 1995] and [NRC, 1995; at conversion rate of £1= $1.50]
A reasonable figure for comparison purposes is the figure derived from the European Commissions £2 million value of a human life i.e. £100,000 per person Sv. When applied to untruncated global doses from 10 years of Sellafield and La Hague releases, the values in Table 12 are obtained.
Table 12 Maximum Values for Optimisation Measures
Annual
Global DosesGlobal Doses
Over 10 YearsValue Per
Person Sv £Maximum Values
£ BillionSellafield1,80018,000100,0001.8La Hague5,90059,000100,0005.9Sources: see Table 11
In optimisation studies (i.e. studies to reduce doses as low as reasonably achievable), expenditure up to these amounts should be considered for remedial or abatement measures to reduce these doses. These are very large sums: the amounts that could be spent on abatement measures comfortably exceed annual operating profits at each site.
Chapter Conclusions
This chapter has derived global untruncated collective doses from annual reprocessing releases at Sellafield and La Hague. In order to assist the Committee on Petitions assess the significance of these doses, this chapter has compared these doses with other nuclear related activities and has valued them using conventional Cost Benefit Analysis techniques.
The results are that global untruncated collective doses from annual reprocessing releases may be seen to be very large relative to other nuclear processes. When valued in monetary terms, the valuations are also very large. For example, they easily exceed the annual operating profits of Sellafield. From these considerations, continued operation of these plants do not appear to fulfil conventional expectations of commercial or radiological justification. Clearly, their continued operation depends on other matters, including social and political factors, which lie outside the scope of this report and remain for the Committees and the Parliaments consideration.
Alternative Options
From a global perspective, the so-called alternative options to reprocessing are in fact the preferred options: most spent fuel discharged from reactors worldwide is not reprocessed. The United Nations [UNSCEAR, 2000] has stated that only about 5% to 10% of world spent fuel arisings is submitted for reprocessing: the rest is stored pending final disposal in a repository. Among the countries that operate nuclear reactors, a majority does not reprocess their spent fuel. At national level, most countries have only reprocessed part of their irradiated fuel. Even countries that have made a clear choice and pretend to reprocess all of their spent fuel, like France or the UK, have left large stocks unreprocessed. As of the end of 1998, only 17,000 tonnes of the 30,000 tonnes of spent fuel unloaded from the French reactors (of all types) had been reprocessed [Coeytaux et al, 2000].
Most countries are moving towards storage as a medium-term strategy for spent fuel. According to the IAEA [1999], new developments in spent fuel management concern storage rather than reprocessing and dry rather than wet storage.
This evolution corresponds to a clear decline of the rationale for reprocessing. Storage of spent fuel over the medium-term (20 to 40 years) or long-term (>40 years) is increasingly viewed as a more attractive management option than reprocessing spent fuel. This is particularly the case with dry storage compared to wet storage, i.e. in fuel ponds.
Waste Management Issues
Compared to direct disposal of the irradiated fuel, reprocessing is sometimes presented as a way of sorting waste and recycling valuable resources i.e. the uranium and plutonium contained in spent fuel. This attractive theory does not stand up to rigorous scrutiny, as recent studies have shown (see below).
Re-use of plutonium and uranium
After the closure of the fast-breeder reactor Superphénix in France (decided in 1997), the use of MOX (mix of oxides of uranium and plutonium) in light water reactors is the only rationale left for the reprocessing of spent fuel. Similarly, the use of REPU (uranium from reprocessing) instead of conventional uranium in fuel is the only way to re-use uranium.
In the UK, there is no program for the use of MOX fuel. In France, 20 reactors have the license to operate a maximum of 1/3 MOX loading. Only two reactors use re-enriched reprocessed uranium fuel.
As of the end of 1998, the French reprocessing program has led to the separation of around 84 tonnes of plutonium contained in French spent fuel, or just more than one third of the total plutonium content of the cumulated unloaded fuel (around 223 tonnes of plutonium in 30,000 tonnes fuel). From these 84 t, only 41.9 t had been re-used at the time, or less than 20% of the total production of plutonium in French nuclear reactors. Some of these results are detailed in Annex 26. The situation is even worse as regards uranium, with only 5.5% of the total uranium content of spent fuel unloaded from French reactors being re-used at the end of 1998 [Coeytaux, 2000].
A recent study, commissioned by the French Prime Minister [Charpin et al, 2000] clearly demonstrates the additional cost of reprocessing scenarios. Annex 27 sums up the detailed material and economic balances of the 58 French PWRs (Pressurized Water Reactors), from the first year of operation in 1977 to the theoretical shut down of the last reactor in the years 2040s. One key result of this study is to show that, over the lifetime of operating reactors, reprocessing could only reduce by some 15% the quantities of plutonium in final waste, assuming that all MOX fuel and some of the uranium fuel would not be reprocessed as it is presently the case. This allows for an economy in natural uranium of around 8%. These results are obtained at very high cost. Each ton of plutonium that is effectively avoided through reprocessing/reuse and not going into final disposal costs about 1 billion FRF.
Final volume of waste
Reprocessing requires the final disposal of vitrified wastes plus the direct disposal of some spent fuel, and various additional wastes produced through reprocessing, such as bituminised waste, hulls and nozzles, technological waste, and most separated plutonium and uranium which is not re-used. Not only does the direct disposal option produce fewer waste categories, it also produces smaller volumes of final waste. Spent MOX fuels have much higher heat outputs than spent uranium fuels, and thus require much longer storage times before disposal and/or much larger volumes in any final repository. These factors imply much larger costs for handling spent MOX fuel than ordinary uranium fuel.
According to preliminary specifications defined by ANDRA in 1998 for final disposal in a deep ground repository in clay, the same type of small galleries only with different lengths could be used to store either canisters of vitrified waste, or UOX or MOX spent fuel. One gallery could receive 8 canisters of vitrified waste, or 4 so-called S3U packages, each containing 3 assemblies of spent UOX, or 2 SM packages, each containing 1 assembly of spent MOX. The respective length of the galleries would be around 20, 28 and 17 m; the volume of one package (including overpack of the canister) is around 0.5, 4.1 and 1.9 m3. Assuming that the reprocessing of one UOX assembly in La Hague produces around one canister of vitrified waste, these ANDRA concept lead to the following volume orders:
Disposal of vitrified waste from the reprocessing of 1 UOX assembly:
0.5 m3 of package, 12.5 m3 of package plus structure;
Direct disposal of 1 spent UOX assembly:
1.4 m3 of package, 11.5 m3 of package plus structure;
Direct disposal of 1 spent MOX assembly:
1.9 m3 of package, 42.5 m3 of package plus structure.
These results can be used for a basic comparison of the two options: (a) the direct disposal of 8 UOX and (b) the reprocessing of 7 UOX plus the direct disposal of 1 MOX. For 8 assemblies, the reprocessing option only produces 5.5 m3 of HLW, while the direct option produces 11 m3. But, if including the volume of the structures in the calculation, the ratio is of 92 m3 for direct disposal against 130 m3 for reprocessing. Again, this is not taking into account the additional waste in the reprocessing option, like unrecycled uranium, technological and process ILW from reprocessing, etc.
Economics of Direct Disposal vs. Reprocessing
The economic advantages of direct storage of spent fuel versus reprocessing are considerable. In simplified terms, reprocessing may be viewed 2 to 3 times more expensive than wet storage, and wet storage about 4 to 20 times more expensive than dry storage. It is not surprising that, in worldwide terms, nuclear utilities are moving towards dry storage solutions, including utilities in the US, Canada, Germany, Russia and many eastern European countries.
Comparative costs studies of storage and reprocessing routes conventionally require examination of the costs of all stages of the fuel path from reactor discharge through to final (often termed direct) disposal in a permanent repository. Four major studies have examined these matters: the German utilities studies, the OECD/NEA study, the EWI study at the University of Köln, and the recent Charpin study in France. Their main results are presented in Table 13 after they are briefly summarised.
German Utilities Studies. Main German utilities studies were carried out by three German institutes, Rhine-Westfalische Energie (RWE) utility, Vereinigung Deutscher Elektrizitätswerke (VDEW) the German Fuel Industry Association, and Projekt Andere Entsorgung at the Kernforschungszentrum Karlsruhe (PAE-KfK), a government-funded research agency in the early 1990s. These predicted direct disposal would be approximately 50% (RWE and PAE-KfK) to 70% (VDEW) less expensive than reprocessing.
Other national studies agree with these studies. A report by the German Federal Rechnungshof [BRH, 1993], the national parliamentary audit office, stated that reprocessing had become twice as expensive as storage, and that reprocessing was no longer feasible. In a report prepared for the Irish government on THORP, Berkhout [1993] estimated, using conservative assumptions, that dry storage/disposal costs were approximately half reprocessing/disposal costs.
OECD/NEA Study. In 1994, the OECD/NEA examined levelised lifetime fuel cycle costs [OECD/NEA, 1994]. The report was concerned to develop fuel costs averaged over the whole fuel cycle. The consequence was that relevant costs were calculated on a lifetime basis and not discounted to a start up date. This resulted in reprocessing and once through costs being about equal.
However the chairman of the OECD Expert Group which drafted the report refuted the reports main conclusions [NuclearFuel, 1995a]. The chairman, Dr. David Groom of UKs Nuclear Electric (now British Energy), stated that back-end costs were not spread over the whole fuel cycle, and that reprocessing costs were incurred immediately. On the other hand, most storage, and all encapsulation and disposal costs would occur many years hence and could be discounted at 5% over decades. COGEMA, whose directing manager was chairman of OECDs Steering Committee for Nuclear Power, replied stating that discounting to this extent was inappropriate [NuclearFuel, 1995b]. This issue remains unresolved by the OECD.
The figures that reflect the view taken by the Chairman of the Expert Group are as follows: with $340 per kg HM (range $85-410), direct disposal is more than twice cheaper than reprocessing, which total cost is $775 per kg HM (range $565-830). This approach is preferred as it reflects more accurately the position of utilities and governments faced with the decision between storage and reprocessing. The figures indicate that in the reference case the predicted costs of the storage route were less than half the predicted costs of the reprocessing route.
The main conclusion reported by the chairman of the OECD Expert Group was that storage was predicted to be half the cost of reprocessing. Nevertheless, the OECD report was criticised by the EWI report [Hensing and Schulz, 1995] see below for unrealistic assumptions, which substantially reduced reprocessing costs. These included the postponement of reprocessing to the year 2006, high uranium prices, new reprocessing plant being built, a low price for reprocessing services, and a low price for MOX fuel fabrication. In addition, the OECD report used a positive value for plutonium ($5,000/kg) and uranium ($33-$135/kg) extracted from reprocessing. These assumptions were (and are) not widely followed. For these reasons, OECD estimates of reprocessing costs are considered to have limited applicability.
EWI Report. The Energie Wirtschaftliches Institut (EWI) at Köln University evaluated various waste disposal options from the viewpoint of a nuclear utility [Hensing and Schultz, 1995]. The EWI Institute has close working contacts with the German nuclear industry. The study carried out a comprehensive financial appraisal of both the storage and reprocessing routes using a zero discount rate. It concluded that direct disposal had a clear cost advantage over the reprocessing option with the disposal cost option being 48% lower than that of reprocessing option. Calculated over the German nuclear industry, the cost advantage amounted to 31.5 million DM or $20 million per year. The report stated that its estimated disposal costs were lower than those calculated by the German Fuel Industry Association due to assumed higher fuel burn-ups in the EWI scenario.
Charpin Study. The recent study commissioned by the French government [Charpin et al, 2000] illustrated the additional cost of reprocessing plus MOX scenarios. The all reprocessing scenario produced additional costs of FF39 billion, in comparison with the abandonment of reprocessing in 2010 scenario, representing FF800 million per year of remaining power plant life. The storage option was much less costly: total savings compared to the reprocessing scenario were FF164 billion (5.5% of total cost), i.e. a saving of more than FF2 billion per year over remaining power plant life, or around FF2.7 billion per GWe. This saving is reflected in total average cost per kWh of 13.65 centimes, 0.5 to 1.5 centimes lower than average costs in other scenarios (see Annex 27).
Comparison of costs per kWh. Table 13 below sets out results of studies, which have compared costs per kWh of storage/disposal and reprocessing options. Strictly speaking, these studies are not comparable because of different assumptions employed and different values in currencies at various times, however the ratios in the final column may be compared. Storage/direct disposal is consistently less expensive than reprocessing, whichever method, part of the fuel cycle, or discount rate is used.
Table 13 Fuel Cycle Costs (1)
StudyStages
comparedDiscount RateReprocessingDirect DisposalRatio Reprocessing to Disposal CostsKfK/EWI [1984]Back-end0%0.560.381.47OECD/NEA [1985] Complete fuel cycle5%>2.171.9799%) detriment. [see IAEA, 1995]
(c) Uncertainties
Inevitably, uncertainties remain about the existence, sizes and habits of populations, climate, and the environment for long periods into the future. For example it is expected that another ice age will peak in the northern hemisphere in approximately 10,000 years and that repeated glacial cycling will occur thereafter [NRPB, 1992].
However the use of uncertainty as a reason for avoiding the use of collective dose does not appear to satisfy the Precautionary Principle, which states, inter alia, that lack of scientific certainty should not be employed as a reason for deferring measures to enhance the quality of the environment [Hey, 1995]. The precautionary principle is one of the supporting principles underpinning the policy of sustainable development formally accepted by the European Commission at the 1992 UN Conference on Environment and Development.
In addition, similar large uncertainties in other parameters used in radiation protection do not prevent their use. For example, large uncertainties exist in the assessment of terrestrial foodchain doses [Smith et al 1998], and in estimates of individual doses to members of critical groups from projected radioactive waste repositories arising 104 to 106 years in the future [Neall et al, 1994]. Of course, these uncertainties are acknowledged, but they do not prevent publication and peer discussion, nor their usefulness for heuristic [McCombie et al, 1991; NAGRA, 1994] or for decision-taking [AECL, 1994] purposes. Estimates of collective dose should be treated similarly.
(d) Comparisons with Background Radiation
Collective doses are received from background levels of radiation (on average there are large variations from one area to the other about 2.4 mSv per person per year in the UK and France) and some commentators compare collective doses from discharges with background doses, in attempts to put them into context [see, for example, RWMAC, 1993; Clarke, 1994; Coulston, 1994; BNFL, 1998]. Such comparisons run the risk of inviting the lay reader to infer that anthropogenic collective doses, and the practices which caused them, are therefore acceptable.
A number of objections can be made against such comparisons. First, comparisons with natural background doses infer that background radiation may be viewed with equanimity. This is not quite the case, of course. The NRPB has estimated that natural background radiation results in about 6,000 to 7,000 UK cancer deaths per year in the UK [Robb, 1994]. The application of the collective dose and the ICRP risk factor to the French population leads to a similar figure for France.
Second, a number of authors have stated that comparisons of radiation exposures from anthropogenic releases with natural background radiation levels are inappropriate. See comments by Lindell [1989], NRPB [1990], Webb et al [1983] and in European Commission documents, for example chapter 8.3.4 in Bush et al [1984]. Comparisons with background radiation of course conflate different, i.e. naturally-occurring and anthropogenic, risks. Risks from anthropogenic releases are subject to social and political processes as the Committees hearing attests: background radiation risks are not.
Third, comparisons with background exposures are not used to justify the acceptability of industrial discharges of naturally occurring chemical toxins, e.g. carbon monoxide, ozone, dioxins or furans.
Finally, the ICRP system of radiation protection of limitation, optimisation and justification [ICRP, 1991] notably refrains from using background radiation as a criterion of radiological acceptance.
Annex 7 Individual Exposures from Consumption of Seafood around Sellafield
Table 14 Individual Radiation Exposures from Consumption of Irish Sea Fish and Shellfish
Exposed population(1)FoodstuffsExposure (mSv/a)14C60Co90Sr99Tc106Ru137CsSellafield fishing communityplaice, cod, crabs, lobsters, winkles0.0050.0020.0050.0160.0030.009Whitehaven commercial fisheriesplaice, cod, Nephrops, whelks0.0020.0020.005Dumfries Gallowayplaice, cod, salmon, crabs, lobster, Nephrops, winkles mussels0.0020.0050.005Morecambe Bayflounders, plaice, shrimps, cockles, mussels0.0030.0020.012Fleetwoodplaice cod shrimps whelks0.0020.010Isle of Manfish, shellfish0.0030.003Northern Irelandfish, shellfish0.0020.005North Walesfish, shellfish0.002Member of public(5)plaice, cod0.001(continued)238Pu239Pu + 240Pu241Pu241AmOther(6)ExtTotalSellafield fishing communityplaice, cod, crabs, lobsters, winkles0.0080.0460.0100.082
