Radioactivity - OSPAR Strategy with Regard to Radioactive Substances
OSPAR
Report by the United Kingdom on Intentions for Action at the National Level to Implement the OSPAR Strategy with Regard to Radioactive Substances (October 1999)
Executive Summary
This report outlines the intentions of the United Kingdom for action at the national level to contribute to implementation of the OSPAR Strategy with Regard to Radioactive Substances. Its purpose is to inform the work of the group of lead countries preparing proposals on actions that the OSPAR Commission could take in the time frame set out in the Strategy. The OSPAR Working Group on Radioactive Substances (RAD) meeting in January 2000 will consider the group's proposals.
The OSPAR Strategy builds on the commitment in the 1992 OSPAR Ministerial Declaration to work towards further reductions in radioactive discharges to the marine environment, through application of Best Available Techniques (BAT). Over the past two decades, the application of BAT has led to substantial reductions in radioactive discharges from UK installations. The UK is strongly committed to the continuation of this process, in line with the principles and time frame of the OSPAR Strategy.
The UK is developing its own national strategy for reducing radioactive discharges. This will set the framework through which the UK will deliver its contribution to the required reduction in environmental levels of radioactive substances in the OSPAR maritime area, by 2020. Development of the UK strategy will be a transparent process and the document will issue in its final form in the second half of 2000.
The UK considers it important that OSPAR should agree a common interpretation of the terms "historic levels" and "close to zero", in paragraph 4.1b of the OSPAR Strategy. A further important consideration, for the UK strategy and more generally for OSPAR, will be monitoring and modelling of environmental levels of radionuclides. The UK considers it important that a co-ordinated OSPAR approach be developed, and suggests that RAD considers developing common predictive models and common criteria and methodologies for monitoring levels of radioactive substances in the marine environment.
As a country with a large and complex nuclear industry, the UK has the opportunity to make a significant contribution to the achievement of the OSPAR Strategy. Because of its legacy of nuclear fuel cycle activities over the last fifty years, the UK faces a more demanding task than many other OSPAR Contracting Parties in meeting the OSPAR requirements. But it is a task that the UK is committed to completing within the agreed time frame and taking account of the guiding principles set out in the OSPAR Strategy.
Report by the United Kingdom on Intentions for Action at the National Level to Implement the OSPAR Strategy with Regard to Radioactive Substances
1: Background
2: Objective and Scope of the OSPAR Strategy
3: OSPAR Strategy guiding principles
4: The use of radioactive substances in the UK
5: UK regulatory arrangements
6: Implementation to date of the reduction strategy
7: Process and timetable for further implementing the OSPAR Strategy
8: Outline content of UK national strategy
9: Modelling and monitoring
10: Interpretation of technical terms
11: Conclusion
Annex 1: UK initial views on the technical terms included in the OSPAR Strategy
1. Background
1.1 The January 1999 meeting of the OSPAR Working Group on Radioactive Substances (RAD) agreed arrangements for intersessional work to suggest how the OSPAR Commission could identify and take the actions required to address paragraph 4.1a of the OSPAR Strategy with Regard to Radioactive Substances (referred to subsequently as "the OSPAR Strategy"). The OSPAR Strategy builds on the commitment in the 1992 Paris OSPAR Ministerial Declaration, which recognised the need to reduce radioactive discharges from nuclear installations to the marine environment and agreed to work towards further reductions of such discharges by applying Best Available Techniques (BAT). The OSPAR Strategy states that, by the year 2000, the OSPAR Commission will, for the whole maritime area, work towards achieving further substantial reductions or elimination of discharges, emissions and losses of radioactive substances.
1.2 To this end, a group of co-lead countries was established to prepare a draft report for RAD 2000, taking into account, inter alia, national reports from contracting parties. These national reports will outline the intentions of Contracting Parties for implementing the OSPAR Strategy in their countries, their timetables for doing so and their views on the technical terms included in the Strategy. This document is the United Kingdom's national report.
2. Objective and Scope of the OSPAR Strategy
2.1 The principal objective of the OSPAR Strategy is to prevent pollution of the maritime area from ionising radiation through progressive and substantial reductions of discharges, emissions and losses of radioactive substances. The ultimate aim is concentrations in the environment near background values for naturally occurring radioactive substances and close to zero for artificial radioactive substances. In achieving this objective, account is to be taken, inter alia, of legitimate uses of the sea, technical feasibility and radiological impacts on man and biota.
2.2 It is clear that the OSPAR Strategy will apply to radioactive discharges resulting from nuclear fuel cycle activities, including decommissioning and the clean-up of historic wastes. It is the view of the UK that the OSPAR Strategy also applies to radioactive discharges from the non-nuclear industry (including discharges of natural radionuclides, such as polonium isotopes from phospho-gypsum processing), and those from "small users" of radioactive substances. The UK considers that a proportionate approach should be taken, whereby the greatest attention is given to the most radiologically significant discharges and those shown to present most risk of damaging the marine environment.
3. OSPAR Strategy guiding principles
3.1 The OSPAR Strategy sets out a number of guiding principles, which the UK supports and reflects in its policy and practice. First among these is that assessments made, and programmes and measures adopted, by the OSPAR Commission to achieve the above objective should be in accordance with the general obligations of the OSPAR Convention and should involve the application of:
- the precautionary principle;
- the polluter pays principle;
- best available techniques (BAT) and best environmental practice.
3.2 the precautionary principle – by virtue of which preventive measures are to be taken when there are reasonable grounds for concern that substances or energy introduced, directly or indirectly, into the marine environment may bring about hazards to human health, harm living resources and marine ecosystems, damage amenities or interfere with other legitimate uses of the sea, even when there is no conclusive evidence of a causal relationship between the inputs and the effects.
3.2.1 This is put into practice in the UK through the principles set out in Sustainable Development – the UK Strategy (Cm 2426), that:
- decisions should be based on the best possible scientific information and analysis of risks;
- where there is uncertainty and potentially serious risks exist, precautionary action may be necessary; and
- ecological impacts must be considered, particularly where resources are non-renewable or effects may be irreversible.
More specifically, it is UK policy that radioactive wastes should be managed and disposed of in ways that protect the public, the workforce and the environment. This demands that radioactive wastes are not unnecessarily created, and that such wastes as are created are managed safely and disposed of appropriately.
3.3 the polluter pays principle – by virtue of which the costs of pollution prevention, control and reduction measures are borne by the polluter. It is UK policy that the producers and owners of radioactive waste are responsible for bearing the costs of its management and safe disposal, including regulatory and research costs.
3.4 best available techniques (BAT) and best environmental practice, including, where appropriate, clean technology – where BAT is defined as "the latest stage of development (state of the art) of processes, of facilities or of methods of operation which indicate the practical suitability of a particular measure for limiting discharges, emissions and waste.
3.4.1 In determining whether a set of processes, facilities and methods of operation constitute BAT in general or in individual cases, special consideration should be given to:
- comparable processes, facilities or methods of operation which have recently been successfully tried out;
- technological advances and changes in scientific knowledge and understanding;
- economic feasibility;
- time limits for installation in both new and existing plants;
- the nature and volume of the discharges and emissions concerned."
3.4.2 The concept of BAT is given effect, in the control of nuclear licensed sites in the UK, through the application of Best Practicable Means (BPM). BPM is that level of management and engineering control that minimises, as far as practicable, the release of radioactivity to the environment whilst taking account of a wider range of factors, including social and environmental factors, cost-effectiveness, technological status, and operational safety. BPM is thus an alternative formulation of the concept of BAT as defined in the OSPAR Convention. In particular, it corresponds with the OSPAR criteria in covering the provision, maintenance and manner of operation of any plant, machinery or equipment which is used and the supervision of the operations involved, as well as in permitting economic feasibility of the techniques to be considered. Revised guidelines for the application of BAT were agreed by the June 1999 meeting of the OSPAR Commission (OSPAR 99) and the UK is currently evaluating these.
3.5 The guiding principles of the OSPAR Strategy further provide that, when adopting OSPAR programmes and measures relating to radioactive substances, including waste, the Contracting Parties shall also take account of:
- the recommendations of other appropriate international organisations and agencies;
- the monitoring procedures recommended by these international organisations and agencies;
- existing scientific assessments of dose and risk as part of the tools for setting priorities and developing action programmes;
- the relevant international conventions and Contracting Parties' obligations under international law relevant to this OSPAR objective.
3.5.1 The UK is a Member State of the European Union and is subject to the terms of the Euratom Treaty. This makes provision for basic Community standards to protect the health of workers and the general public against the dangers arising from ionising radiation. A revised Basic Safety Standards Directive is to be implemented by all Member States by May 2000. The Euratom Treaty also includes obligations for Member States to monitor radioactivity in the environment (Article 35), to provide the European Commission with the results of such monitoring (Article 36) and to provide general data on any plan for the disposal of radioactive waste (Article 37).
3.5.2 The UK is a party to the London Convention 1972, a 1993 Resolution of which banned the dumping at sea of low-level radioactive waste and, together with earlier resolutions, effectively imposed a complete ban on the sea dumping of all radioactive waste. The UK has signed, but has yet to ratify, the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management. When this legally binding Convention comes into force, implementation of its requirements by Contracting Parties will be evaluated through a system of reporting and peer review.
3.5.3 A number of international organisations and agencies have published recommendations that are relevant to the management of radioactive waste discharges in the UK. These include:
- the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR),
- the International Commission on Radiological Protection (ICRP),
- the United Nations International Atomic Energy Agency (IAEA),
- the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development (NEA) and
- the United Nations International Maritime Organisation (IMO).
3.5.4 UNSCEAR was established in 1955 to monitor the radiological effects of fallout from the atmospheric testing of nuclear weapons. It has become the primary international body reviewing human exposure to all sources of radiation, natural and artificial. Its estimates of doses and effects are taken as definitive figures by other international bodies, including the ICRP.
3.5.5 The radiological protection principles underpinning the UK's policy take account of the 1990 Recommendations of the International Commission on Radiological Protection (ICRP 60) and the National Radiological Protection Board's formal advice in its 1993 Board Statement on those recommendations. The system of protection recommended in ICRP 60 includes the concepts of:
- justification – whereby any practice involving exposures to radiation can only be adopted if it produces sufficient benefit to offset the radiation detriment it causes;
- optimisation – which requires that individual doses, the number of people exposed and the likelihood of their exposure should all be kept as low as reasonably achievable (ALARA);
- dose limitation – aimed at ensuring that no individual is exposed to unacceptable radiation risks in any normal circumstances.
3.5.6 The IAEA Safety Fundamentals document, The Principles of Radioactive Waste Management Policy, defines the objective of radioactive waste management as being: "to deal with radioactive waste in a manner that protects human health now and in the future, without imposing undue burdens on future generations." This reflects the principle of sustainable development. It involves the timely creation of an effective national legal framework and an associated organisational infrastructure to provide the basis for appropriate management of radioactive waste.
3.5.7 The NEA's Radioactive Waste Management Committee has published a collective opinion on the environmental and ethical basis of geological disposal of long-lived radioactive wastes. This has implications for waste management options in the UK.
3.5.8 The IMO encourages the highest standards of marine safety and the prevention of marine pollution from ships. Its work includes consideration of de minimis levels of radioactivity in materials dumped at sea.
4. The use of radioactive substances in the UK
4.1 In common with other developed countries, the UK has used radioactive substances for medical and other non-nuclear purposes since the early part of the twentieth century. The commercial production of radio-isotopes for medical and research purposes continues to be an important activity at the Nycomed Amersham premises in Amersham (Buckinghamshire) and Cardiff. Early experience with radium and X-ray apparatus in the UK and elsewhere, and concern about the health effects associated with exposure to ionising radiation, led to the formation of the ICRP, more than seventy years ago.
4.2 The discovery of nuclear fission opened the way to the industrial, commercial and defence applications of radioactive substances. Shortly after the end of the Second World War, the UK embarked on an expanded programme of nuclear research and development. Initially, the UK programme was focussed on nuclear weapons production. Subsequently, the production of electrical power gained importance. The UK constructed facilities for research into various aspects of the civil nuclear fuel cycle at a number of sites, from the 1950s.
4.3 The UK's first commercial nuclear power station, at Calder Hall in Cumbria, opened in 1956. This was a gas cooled, Magnox prototype and was followed by a similar station at Chapelcross in 1959. Nine full-scale Magnox stations were built between 1957 and 1970, three of which are no longer operational. The UK commissioned five Advanced Gas Cooled Reactor (AGR) stations between 1976 and 1988. The UK's only Pressurised Water Reactor, at Sizewell in Suffolk, was opened in 1995. In addition, associated fuel cycle facilities for uranium enrichment, fuel fabrication, spent fuel reprocessing and low-level waste disposal were constructed at a number of sites. The principal operational fuel cycle sites are the reprocessing and waste management operations at Sellafield, uranium enrichment at Capenhurst, fuel fabrication at Springfields and the surface low level waste disposal facility at Drigg. The map at Figure 1 shows the locations of the principal sources or radioactive waste discharges in the UK.
Figure 1. Principle sources of radioactive waste disposal in the UK
4.4 This long history of nuclear development has enabled the UK to build an internationally recognised base of expertise in radiation protection in relevant industrial process technologies and in the behaviour of radionuclides in the environment. But it has also resulted, at Sellafield and Dounreay, and to a lesser extent at other sites in the UK, in a historic legacy of radioactive wastes and of contaminated plant and equipment. This legacy must now be dealt with, in the interests of sustainable development, to reduce onsite risks and to avoid leaving a burden to future generations. In addition, older facilities are coming to the end of their lives and will need to be decommissioned and dismantled. The UK is facing these challenges in a responsible way that recognises the need to protect both human health and the environment. The UK's ongoing nuclear operations in the 21 st Century will result in very low discharges to the environment. Discharges arising from decommissioning and clean-up operations will need to continue for some time but will also be kept very low through the application of BPM.
5. UK regulatory arrangements
5.1 Before looking at the means by which the UK intends to implement the OSPAR Strategy, it may be useful to explain briefly the legislative and regulatory framework that applies to radioactive discharges in the UK.
5.2 When the United Kingdom Atomic Energy Authority (UKAEA) was created in 1954, it was recognised that new legislation was needed to provide adequate protection of the environment against pollution that might result from the expanding nuclear development programme. The Atomic Energy Authority Act (1954) removed responsibility for the control of radioactive discharges from local authorities and provided a system of central control, whereby no such discharges could be made from UKAEA sites unless authorised by the relevant Government Ministers. The Radioactive Substances Act 1960 was the first comprehensive legislation applying to all radioactive discharges in the UK. Today, radioactive wastes, including discharges, are closely regulated under the Radioactive Substances Act 1993, by the relevant competent authorities. These authorities are the Environment Agency in England and Wales, the Scottish Environment Protection Agency in Scotland, and the Environment and Heritage Service in Northern Ireland.
5.3 When the competent authorities consider applications for discharge authorisations, or variations to existing authorisations, they must take account of Government policy, including the principles of sustainable development, justification, optimisation and dose limitation outlined above (paragraph 3.5.5). It has been the UK's policy since 1986 (Cmnd 9852) that members of the public should not be exposed to a dose of more than 1 mSv/y from all man-made sources of radioactivity, other than from medical exposure. This was the dose limit recommended by the ICRP in 1990 (ICRP 60) and is also the dose limit set in the 1996 Euratom Basic Safety Standards Directive (96/29), the relevant provisions of which will be formally implemented in UK law next year through the revised Ionising Radiations Regulations.
5.4 The dose estimates used by the regulatory authorities in setting limits on the discharge of specific radionuclides assume that discharges would be maintained at the limits for all radionuclides specified. Since this is unlikely to happen in practice, the doses resulting from actual discharges from the site will be lower than these estimates. In addition to placing numerical limits on the radioactivity discharged, authorisations under the Radioactive Substances Acts have required operators to use BPM to minimise the activity of waste discharged. The authorisation also imposes requirements on the operator to carry out monitoring of levels of discharged radionuclides in the surrounding environment. All authorisations for the disposal of radioactive waste are kept under review. This is an important mechanism to ensure effective control over radioactive discharges. Whilst authorisations for discharges from civil nuclear installations and those defence nuclear sites that are managed under contract by civilian organisations are granted on a site basis, other discharges resulting from military activities are addressed in a global fashion.
5.5 The UK authorises the discharge of radioactive substances from a range of operations connected with the nuclear fuel cycle. These include uranium enrichment and fuel fabrication, nuclear power production, reprocessing of spent nuclear fuel and disposal of low-level radioactive waste. In addition, authorised discharges are made from research and defence installations, from establishments that produce radio-isotopes for use in medicine and research, and from other small, non-nuclear users of radioactive substances.
5.6 The Scottish Environment Protection Agency, the relevant regulatory authority in Scotland, has recently (August 1999) issued new authorisations for the Dounreay site. These greatly reduce the allowed discharge limits of radioactivity to the marine environment and substantially improve regulatory controls over operations and radioactive discharges. At the time of submission of this report, an announcement is expected shortly on BNFL's application to vary some discharge authorisations for the Sellafield site.
6. Implementation to date of the reduction strategy
6.1 Since the introduction of general legislation to regulate the use of radioactive substances (the Radioactive Substances Act 1960), the UK has consistently applied the radiological protection principles and regulatory arrangements described above, in order to reduce the levels of radioactive discharges and the doses of ionising radiation to both humans and the wider environment. Levels of radionuclides in the environment have been carefully monitored to ensure they remain within safe levels.
6.2 At no time has there been a significant risk that either humans or the wider environment would suffer harm from authorised UK radioactive discharges or emissions. Since "pollution" is defined, both in the UN Convention on the Law of the Sea and in the OSPAR Convention, in terms of the causation, or the likelihood of causation, of harm and similar deleterious effects, there has been no pollution of the marine environment from authorised UK radioactive discharges and emissions.
6.3 At the time the Sellafield reprocessing facility was commissioned, the techniques used, and therefore the levels of discharges, represented the application of BAT. Since 1980, the redefinition of BAT for reprocessing, in the light of improvements in scientific understanding and engineering, has led to substantial reductions in the levels of discharges.
6.4 Reprocessing was undertaken at the Dounreay experimental facility as part of a programme of turning the assets there to good account. Reprocessing has been suspended since November 1996 and the Government announced in June 1998 that Dounreay will take on no further commercial reprocessing work. This means that reprocessing at Dounreay will come to an end when the plant has completed the reprocessing of its own fuel, spent fuel imported under existing commercial contracts and the small amount of Highly Enriched Uranium (HEU) imported from Georgia on non-proliferation grounds.
6.5 Potentially significant radioactive discharges from non-nuclear industries have also been carefully monitored. The closure of the Allbright and Wilson phosphate fertiliser plant at Whitehaven removed the only substantial source of radioactive discharges of this kind in the UK.
6.6 In this way, over the past two decades, the application of BPM/BAT has led to substantial reductions or elimination of discharges, emissions and losses of radioactive substances from UK installations, in line with the commitments made in the 1992 and 1998 OSPAR Ministerial Declarations.
7. Process and timetable for further implementing the OSPAR Strategy
7.1 The task now is to take forward the strategy and to improve yet further on the UK's control of radioactive discharges, emissions and losses. It is essential to the success of any strategy that those who are to be responsible for putting it into effect should be involved in its formulation. For this reason, the UK Government is working with the relevant regulatory authorities and with users of radioactive substances (including the nuclear operators), to arrive at a UK strategy for radioactive discharges that will be deliverable in practice. This strategy will reflect the objectives and time frame set down in the OSPAR Strategy and will contribute to the required reduction in environmental levels of radioactive substances in the maritime area.
7.2 The development of a national strategy will be informed by discussion with organisations that discharge radioactive substances (including enhanced concentrations of naturally occurring radioactive materials) to the environment, of possible means of achieving the OSPAR target for levels in the environment by 2020. It will also take account of likely developments in process technologies (including abatement) and waste management practices over the next twenty years. The aim will be to produce profiles of discharge levels against time to illustrate promising options for discharge reduction. The technical feasibility of these options will be assessed, as will their likely consequences in terms of changes in radiological impact, accident risk, costs, and, where data are available, environmental effects. These profiles may not all show smooth downward slopes, but all will be expected to show discharges leading to extremely small additions to levels in the environment (above historic levels), by 2020.
7.3 The OSPAR Strategy requires the UK to achieve progressive and substantial reductions in its discharges of radioactive substances, taking into account legitimate uses of the sea, technical feasibility and radiological impacts to man and biota. This will be a key principle in developing the national strategy, alongside the need to keep doses to the public and workers as low as reasonably achievable. Equally, there will need to be a common appreciation among OSPAR Contracting Parties of what the OSPAR Strategy requires in terms of levels of radionuclides in the marine environment and how such levels are to be determined. This is likely to form an important part of the work of RAD for some years to come. As a consequence, the UK will need to adjust and refine its national strategy as this work progresses.
7.4 The draft UK national strategy for discharges of radioactive substances will cover the period 2001 to 2020. Nuclear operators and other users of radioactive substances will be expected to plan their discharges to align with the national strategy. Although it will be based on the most accurate and up-to-date information, assumptions and methodologies, the national strategy will not be intended to provide an immutable forecast of discharge limits over its 20-year lifespan. The process of reviewing and adjusting discharge authorisations will continue as at present, guided by the national strategy but taking account of other factors, such as technological developments and future energy policies.
7.5 The development of the draft national strategy will be a transparent process, subject to full public consultation. This will conform with the UK's policy on open Government, including the provisions of the UK's code of practice on access to Government information.
7.6 When the UK national strategy is published in its final form, before the end of 2000, the Government will also issue statutory guidance to the competent authorities, endorsing the national strategy as being in line with Government policy. The competent authorities would then ensure, as a statutory function and as part of a regular process of reviewing discharge authorisations, the adherence of the nuclear operators to the national strategy. It is intended that the strategy itself, and the targets and milestones it sets out, should also be reviewed at intervals of about every four years. These reviews would take into account any changes in international commitments, national legislation and policy, process technology including abatement, sources of radioactive discharges and knowledge about the radiological and environmental effects of radioactive substances.
8. Outline content of UK national strategy
8.1 It is envisaged that the UK national strategy is likely to have the following broad structure and content:
- Introduction: radioactivity and radiation, basic principles and the need for a national strategy.
- International context: IAEA, NEA Euratom and OSPAR initiatives; the OSPAR "Sintra" Strategy; Joint Convention; London Convention; Euratom Treaty and Directives.
- National arrangements: devolved administrations; regulatory regimes.
- Control of discharges: legislation; discharge authorisation process; dose limitation.
- Scope of the National Strategy: discharges from the nuclear industry, other defence applications, other sources; liquid and airborne discharges.
- Trends: historic discharges and resulting environmental consequences and doses; current discharges, environmental levels and doses; projected levels and doses; radionuclides of particular concern.
- Requirement and scope for reducing discharges: radiological, environmental, technological and health & safety considerations; cost effectiveness.
- Targets and milestones 2001 to 2020: operators of nuclear licensed sites; other defence applications; non-nuclear operators and "small users".
- Next steps: implementation through statutory guidance; review of strategy; beyond 2020?
- Summary and conclusions
9. Modelling and monitoring
9.1 It is envisaged that the following aspects will be included in the UK national strategy:
- discharge profiles and modelling of associated levels in the environment;
- monitoring of radioactive substances in the marine environment;
- predicted impacts on man;
- impacts on the marine environment.
9.2 Discharge profiles and modelling of associated levels in the environment
9.2.1 For profiling the discharges of radionuclides likely to reach the marine environment, assumptions would need to be made about the levels and timing of these discharges. Internationally accepted models should then be used for predicting the levels of environmental radioactivity that would result from various discharge profiles.
9.2.2 An appropriate set of radionuclides would need to be identified for this modelling, which might be used as indicators for the behaviour in the marine environment of wider groups of similar radionuclides. Factors to be taken into account might include decay rates, dispersion (by currents and up or down the water column), take-up by various biota, adsorption onto sediments and subsequent release from sediments. Modelling of the future behaviour of radionuclides already in the environment as a result of historic discharges would also need to be carried out.
9.3 Monitoring of radioactive substances in the marine environment
9.3.1 Monitoring and measurement programmes should use a consistent set of environmental media that will give a reliable picture of levels of radioactivity in the marine environment and will accurately reflect trends in those levels over time. The monitoring media chosen should include seawater, sediments, flora and fauna. The selection of appropriate biota should take account of their usefulness in indicating both the movement of radionuclides through the human food chain and the radiological effects of the discharges on species other than man. The UK, like other Contracting Parties, already has a considerable database of measurements for the marine environment around its coasts. OSPAR will need to be consider carefully how continuity and comparability of measurements in terms of radionuclides and environmental media can be maintained, both through time and across the maritime area. Work being carried out by OSPAR in relation to the development of environmental quality criteria, and data used in compiling Quality Status Reports, should also be taken into account.
9.3.2 Monitoring locations should include sites in the vicinity of installations discharging radioactivity, as well as those further afield. In addition, it may be useful to agree some "international" locations outside territorial waters, where monitoring of seawater and possibly some other media would be carried out, to a programme agreed between OSPAR Contracting Parties.
9.3.3 Sampling and measurement protocols should be as consistent as possible to ensure comparability of data. Such protocols would set out sampling frequencies and times, sampling methods, sample sizes, sample treatment and measurement methods and the confidence limits associated with measurements. Separate protocols may be needed for each of the environmental media included in the monitoring programme.
9.4 Predicted impacts on man
9.4.1 In predicting radiological impacts on man, the concept of the "critical group" is used. For a given source, this is the hypothetical group of members of the public who receive the highest dose of radiation from that source, by any pathway or combination of pathways. If one identifies the critical group and ensures that their predicted dose from a source is as low as reasonably achievable, it may be assumed that all other members of the public are exposed to lower doses from that source.
9.5 Impacts on the marine environment
9.5.1 The current system of radiological protection for man, as developed by the ICRP, has in the past been assumed to be sufficient in itself to protect the environment, as it considers man to be the most radiosensitive organism. It may be argued, however, that this approach is not applicable to situations where the exposure of human populations is very low, due to their remoteness from a source or lack of a radionuclide pathway, but exposure of other biota may be high.
9.5.2 At present, it is recognised that a radiological protection framework for species other than humans is at the stage of development, internationally. The UK, other countries and international organisations are funding research projects on radiological effects on non-human species. As part of the OSPAR Strategy, the OSPAR Commission is to undertake the development of environmental quality criteria for the protection of the marine environment from adverse effects of radioactive substances, and report on progress by the year 2003.
9.6 Many of the above considerations will apply to other Contracting Parties as well as the UK. A co-ordinated OSPAR approach to modelling and monitoring would ensure the comparability of data produced by the Contracting Parties. This in turn would help to provide a coherent and comprehensive picture of levels of radioactivity in the marine environment of the whole maritime area. It is suggested that the production of guidance on modelling and monitoring should form a part of the work programme of RAD. The UK national strategy will take account of work carried out by RAD in these areas.
10. Interpretation of technical terms
10.1 RAD 1999 invited Contracting Parties to include in their national reports their views on the technical terms included in the OSPAR Strategy. These terms were taken to be "historic levels" and "close to zero", in paragraph 4.1b of the Strategy. This reads:
"By the year 2020, 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."
10.2 An agreed interpretation of these terms will be essential before any attempt can be made to quantify them in terms of specific radionuclides in specific environmental media. Some initial thoughts on possible interpretations are given at Annex 1. These are put forward as suggested options for discussion, among others. They do not represent a firm UK position.
10.3 Once there is an agreed OSPAR view on the meaning of these terms, work can begin to assign values to them for specific radionuclides in specific environmental media. This latter work will be informed by the development of environmental quality criteria for the protection of the marine environment from adverse effects of radioactive substances, progress on which is to be reported to the Commission by 2003.
11. Conclusion
11.1 A key activity for autumn 1999 will be the preparation, by the group of lead countries, of a paper for RAD 2000. This will propose action by the OSPAR Commission to meet the requirement of paragraph 4.1.a of the Strategy. This report will inform the preparation of the RAD paper. As a country with a large and complex nuclear industry, the UK has the opportunity to make a significant contribution to the achievement of the OSPAR Strategy.
11.2 Because of its legacy of nuclear fuel cycle activities over the last fifty years, the UK faces a more demanding task than many other OSPAR Contracting Parties in meeting the OSPAR requirements. But it is a task that the UK is committed to completing within the agreed time frame and taking account of the guiding principles set out in the OSPAR Strategy. The UK intends to produce a national strategy on radioactive discharges, to cover the period 2001 to 2020, during the second half of 2000.
11.3 It is expected that RAD will carry out work to arrive at an agreed interpretation of the terms "historic levels" and "close to zero". RAD could also consider common predictive models and common criteria and methodologies for monitoring levels of radioactive substances in the marine environment. The UK national strategy will reflect the progress of discussion of these issues.
11.4 The UK envisages updating its national strategy at intervals of about four years. These updates will take account of further OSPAR programmes and measures in this area, including the development of environmental quality criteria. They will also have regard to other relevant legal, policy and technical developments.
Annex 1: UK initial views on the technical terms included in the OSPAR Strategy
"Historic levels"
1. For the purposes of implementing the OSPAR Strategy, there are two possible interpretations of the term "historic levels". It could be taken to mean either:
- fixed numerical values for measured radionuclide levels in the maritime area at a given historical date (e.g. 1998); or
- that element of measured levels at any time calculated to result from the legacy of past discharges rather than from ongoing inputs.
2. The UK's initial view, subject to further discussion, is that "historic levels" in this context is not meant to refer simply to levels found in the past. The intention of the OSPAR Commission when drafting the Strategy was, rather, that expressed in option (ii.) above. On this definition, historic levels would be constantly changing due to dispersion, redistribution and decay, and re-mobilisation from sediments. They would, therefore, need to be accurately modelled and regularly re-calculated for specific datatypes at specific locations.
3. At any point in time, it should be possible to measure actual levels of radionuclides in environmental media and then to model the expected changes in those levels over time due to decay, dispersion, adsorption onto (and release from) sediments etc, in the absence of any future inputs. Even so, there would be no hard and fast figures, just estimates subject to a degree of uncertainty that arises from the accuracy of the model, the sensitivity of measurement equipment and techniques and the natural variability within the population sampled.
4. Another consideration is whether historic levels should be considered in terms of total Becquerels (or total alpha, beta, gamma) or for each individual radionuclide discharged. The UK would propose the latter, since the object would be to build up a time series of reliable and accurate information and we already have many years of radionuclide-specific data for the marine environment around the UK.
"Close to zero"
5. Any attempt to meaningfully quantify the term "close to zero" will also be problematic. One option might be to express "close to zero" in terms of a small percentage of the "historic level", for each radionuclide, once this latter term has been defined. This approach could help RAD to agree "maximum acceptable levels" for environmental concentrations after 2020, which could then be translated back into discharge limits.
6. Another, and perhaps more practical approach in determining "close to zero" might be to make use of the confidence margins that will, in any case, surround the modelling of historic levels and the measurement of actual levels, including the variability inherent in natural media. This kind of approach might require that, by 2020, the contribution of ongoing routine radioactive discharges to concentrations in the marine environment should be indistinguishable in practice from the natural variability in environmental concentrations due to past discharges.
7. Neither of the above approaches would be of help in a case where decommissioning and clean-up operations may require the release of low levels of unusual radionuclides, not released in significant amounts during operations at the site, since "historic levels" would not apply. Other methods of arriving at acceptable environmental levels would be needed in these instances. One possibility would be to compare the environmental level of such a radionuclide with that of the historic level of a previously discharged radionuclide which has a similar radiotoxicity.
Updating of estimates
8. Modelling of discharge profiles and associated radionuclide concentrations would need to be carried out regularly, and discharge limits adjusted accordingly, to ensure that actual levels in the environment remain "on track". It is likely that, given very low levels of discharges and modelling that becomes more accurate with experience, this process would only need to be repeated when discharge authorisations are being reviewed. For the UK, we would envisage this being carried out about every [three to] five years. As some discharges are periodic rather than constant, for operational reasons, more frequent revision of models may be inappropriate.
Published 25 October 1999
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