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Radioactive Waste Disposal - Where do we go from here ?

This report was written by Sir Gordon Beveridge and Professor Charles Curtis from the government advisory committee, the Radioactive Waste Management Advisory Committee, and presented by Prof Curtis to the Nuclear Free Local Authorities Annual Conference, at Caernarfon in October 1998

Introduction

I am here today to make this presentation on behalf of the Radioactive Waste Management Advisory Committee (RWMAC for short). The RWMAC, as most of you will know, is a national advisory committee that provides independent advice to the Government on issues relating to the management of radioactive waste.

The presentation that I shall be giving has been prepared jointly with Sir Gordon Beveridge, the chairman of RWMAC, who is unable to be here today. What I shall be talking about primarily is how, in the longer term, the United Kingdom should deal with its stocks of intermediate level radioactive waste, but I shall also be touching on one or two high level waste issues, most notably in the context of possible co-disposal.

Types of waste

Before moving on, perhaps if would help if I said something more about the three mainly UK categories of radioactive waste.

Waste with the lowest levels of contamination, or radioactivity, is referred to as low level waste. This consists of items such as workers clothing, laboratory waste etc. which can already be disposed of at the existing UK near surface disposal facilities at Drigg and Dounreay.

The next level up is intermediate level waste which comprises, for example nuclear reactor components and the irradiated metal cladding for nuclear reactor fuel. There are already about 70,000 cubic metres of intermediate level waste and the current UK nuclear programme will ultimately increase this volume to somewhere between 250,000 and 300,000 cubic metres. (Most of this is already ìcommittedî: if all NPPs were to shut down immediately and all reprocessing cease - except old magnox fuel which is chemically very unstable - some 230,000 cubic metres would constitute the ILW inventory).

Finally, there is a small volume of high level waste from the reprocessing of spent nuclear fuel. This are currently about 700 cubic metres of high level waste, which the current UK nuclear programme will eventually increase to between 2,000 and 2,500 cubic metres.

The current situation

When the then Secretary of State for the Environment, John Gummer, rejected an appeal by UK Nirex last March for permission to build its Rock Characterisation Facility beneath Sellafield in Cumbria, he effectively brought 15 years of research to an abrupt end. UK Nirex, for those who do not know, is the company formed in 1982 to develop a disposal route for intermediate level waste. That exercise cost the nuclear industry £450m and the taxpayer further substantial sums in planning inquiry bills. It also effectively left the UK back at square one in respect of its plans for the disposal of intermediate level radioactive waste.

The new Labour Government, elected shortly afterwards has yet to say, in light of Mr Gummer's decision, how it wishes to tackle the longer term management of radioactive waste. It will not do so until the House of Lords Select Committee on Science and Technology has reported the outcome of its enquiry into Nuclear Waste Management. This enquiry was announced at the end of last year. The Select Committee is expected to report around the end of this year and thereafter it is likely to take Government Ministers some months to assess the outcome.

The RWMAC was one of the organisations invited to submit written evidence to the Select Committee. This was provided at the end of January. Sir Gordon Beveridge and I give additional oral evidence probably in July and also submitted additional written evidence. What I shall do this morning is to provide you with a summary of the main points of RWMAC's submission to the Select Committee, elaborating on some of the more important points.

The Select Committee requested evidence under a number of specific question headings. I shall start by explaining the overall message that the RWMAC sought to convey and then talk about some of the points made under the specific question headings.

Overall message

The RWMAC's overall message in respect of the long-term management of intermediate level radioactive waste was that:
  • the Committee sees eventual deep disposal of such waste as the only tenable solution within a policy of sustainable development (sustainable development being essentially societal development that does not leave a legacy of problems for future generations)

  • the RWMAC therefore believes that the Government should reaffirm a policy of eventual deep disposal of this waste so as to remove current uncertainty following the failure of the Nirex RCF planning application

  • development of a new planning programme for securing such disposal will take time, and interim storage will be necessary for this period: what is important is that such interim storage is part of a properly-constructed and clearly-stated national management plan rather than essentially a ploy to put off difficult or potentially controversial political action

  • the overall aim should be to avoid unnecessary and accountable delay in the process for securing an eventual deep repository solution

Why deep disposal?

So why does RWMAC consider that eventual deep disposal is the only tenable solution within the context of sustainable development? It is because storage for decay is implausible, as no store, or indeed waste packaging, can be produced such that it will last for the time necessary for the radioactivity to diminish to safe levels, which can take ten thousand years or more (i.e. indefinite storage - requiring regular re-packaging with consequent operator risk. Making the conservative assumption that re-packaging would be required, say, every hundred years, this means that waste would have to be repackaged 100 times within a ten thousand year interval).

A period of interim storage will be necessary but this, RWMAC believes, can be undertaken safely and should be for the minimum period necessary to achieve a deep disposal solution.

Ratification of solution

So if a deep disposal solution is ultimately favoured by the current Government, how should it be ratified?

The RWMAC believes that there must be public acceptance of the chosen solution, and that this requires that the alternative strategies, with their merits and disadvantages, be fully exposed to public scrutiny through consultation processes. It is important that repository development is based on proven science, engineering and technology that is properly evaluated. Secondary questions, such as the extent to which the waste should be monitorable and retrievable once in the repository, also need to be resolved.

Careful thought also needs to be given to the presentation of inherently difficult information to the public. Openness and transparency to allow the UK public to understand what is going on and why, are essential throughout the future planning and development of any deep repository. The RWMAC does not believe that these principles have been fully applied in the past.

Adequacy of knowledge

Do we have adequate knowledge to build a repository? The RWMAC believes that the industry will have the necessary methodologies to develop an acceptable repository safety case by the time final case preparation becomes due. The great majority of these methodologies are already developed, and ongoing research is continuing to fill in the remaining gaps. For example, some further work is required to develop a better understanding of generic transport processes (the role of colloids and the potential for groundwater to be driven by gas) and retardation processes (notably sorption and rock matrix diffusion).

However, the most difficult part of the process is likely to be in persuading other parts of the scientific community and the public of the adequacy of the science, particularly those who may be directly affected by the siting of the repository (even accepting radiological safety, public perception imposes blight through diminished property values - see compensation).

The adequacy of current arrangements

The House of Lords Select Committee asked whether respondents were satisfied with the current institutional responsibilities for nuclear waste in the United Kingdom and, if not, how they might be improved? That is, are the bodies with responsibility for the implementation and regulation of waste management the right ones, and do they have appropriate remits?

The RWMAC believes that the short-term institutional responsibilities for day to day management and regulation of nuclear waste (that is the power generators and BNFL working under the supervision of the Environment Agencies and the Nuclear Installations Inspectorate) are generally acceptable. However, as with any management and control process, these must be subject to periodic review to ensure quality and cost-effectiveness.

Where, however, the RWMAC does have concerns is with the arrangements for the long-term management of such waste, in particular those for securing the development and operation of a deep national repository. In the RWMAC's view, the RCF experience has shown that the current arrangements with UK Nirex operating under existing UK planning laws, are not conducive to the development of a national repository.

Future needs

So how can matters be improved in future? The RWMAC sees the key future needs to be:
  • a more appropriate organisational structure and planning framework

  • greater Government commitment to dealing with the long-term problems of radioactive waste than previous governments have shown in the past, notably to securing a deep repository solution

  • more openness and transparency at every stage of the planning process

  • more clearly defined responsibilities and accountabilities

The RWMAC feels that these might be achieved by:

  • First, the national process for developing a repository would be enshrined in an Act of Parliament. This would give the process more backbone than it has had in the past. If a future administration does not have the same political enthusiasm for either the process or objective of achieving a repository solution, it will have to justify itself and go through the process of amendment to national legislation.

  • The second requirement suggested by the RWMAC is what it has termed a Quality Plan. This would flesh out the processes enshrined in the Act. It would fully define the role of the players and their remits against the top level decision-making process defined in the Act. It would therefore provide the yardstick against which implementation of the Act can be monitored.

  • The third requirement would be the creation of a Statutory Repository Board to provide independent oversight of repository development. The Board would be accountable to Parliament.

    The Chairman and members of the Repository Board would be appointed by the Secretaries of State for the Environment, Transport and the Regions, for Scotland and for Wales. (The Board would comprise independent experts with specialisms such as radiation protection, earth, environmental, physical and social sciences, ethics, planning law, and economics, together with representatives from Government departments, regulators, nuclear operators and the public.

  • The final piece in the jigsaw would be an Executive Disposal Agency. This Agency would be charged with repository development, for which it would be answerable to the Statutory Repository Board. In undertaking this work, the Executive Disposal Agency would follow a process for repository site selection and investigation that had been defined by the Statutory Repository Board.

These arrangements, the RWMAC believes, would offer a much better chance of successful repository implementation than those currently in place. They would, of course, take some time to set in place. In the meantime, the RWMAC believes that the Government should reaffirm a policy of eventual deep disposal for intermediate and high level waste as soon as possible, to fill the policy void created by the RCF decision, and begin formulation of revised arrangements for securing repository development at the earliest reasonably achievable date.

The planning process

The overriding requirement of the repository planning process is that it should make clear who takes what decision at what times on the basis of what remit and in light of what evidence. Once a particular decision is taken, it should not be revisited other than on a clearly defined and pre-specified basis. The current repository planning arrangements are not of this nature.

There is also potential conflict between national and local decision-making. For example, the mechanisms of a local planning procedure were appropriate to the issues of building a Rock Characterisation Facility, but only if considered in isolation from the possibility of future development of the site to provide a national repository, It must also be questionable whether a local planning inspector has the expertise necessary to evaluate adequately the issues relating to the safe siting of a national radioactive waste repository.

That having been said, the Government issued a policy statement in January 1998 called Modernising Planning, which appears to recognise that special arrangements are likely to be needed for the planning of national projects. The RWMAC hopes that this will lead to improvements of the kind necessary for successful repository development.

Site selection

Set in term of an appropriate site selection process, there appears to be no reason in geological terms why a suitable repository site cannot be found somewhere in the UK. The selection process itself will successively filter down through potential sites throughout the country, until a final site is located.

There is, of course, no such thing as absolute safety (zero risk): thus a good site is one that can meet the risk target defined by the regulator. The requirement should not be for the "best" site, rather one that satisfies that specified risk target.

The way in which a site is selected needs careful thought. Acceptability of a site cannot be viewed solely in terms of individual geological (or, more significantly, hydrogeological, since groundwater is the likely escape pathway) attributes. The bottom line is that the repository must be able to meet all regulatory requirements taking into account both natural and engineered barriers. There is a potential danger in the hard-listing of required site features in advance of the selection process, as these may be seized upon in isolation as individual "disqualifiers".

Additionally, the RWMAC believes that the possibility of compensation/incentive payments, that are envisaged in some other countries, for example Switzerland, are worthy of consideration in the UK context for communities that might ultimately be called upon to accommodate the national repository. The possibility of seeking volunteer repository sites, a process which has again been employed overseas, is also worthy of consideration, particularly if compensation/incentive payments can be made available.

Other issues

The Select Committee also posed questions on a number of other issues. Some of these are as follows.

Co-disposal: The first of these other issues concerns the possible co-disposal of intermediate and high level waste. When Nirex was set up in 1982, it was expected to establish disposal facilities for intermediate level waste reasonably quickly in contrast to high level waste which needed to be stored for a period of at least 50 years before disposal is considered, to allow the amount of heat produced to decay. This meant that the Nirex repository, when and as originally proposed, would have been available in the early part of the next century as opposed to the latter part, when high level waste disposal is currently envisaged.

Given the present, now inevitable delay to ILW repository development, there is the opportunity to consider the possible co-disposal of intermediate and high level waste. The RWMAC believes that this is a possibility that should now be explored more fully, preferably sooner rather than later.

An international repository solution? The House of Lords Select Committee posed the question as to whether an international solution to radioactive waste disposal might be sought. It has been suggested that some countries might deem it to be in their interests to offer a host site for a potential international repository, particularly if this allowed them to offset a large proportion of the costs of its construction.

The RWMAC believes that whilst there are arguments potentially in favour of seeking an international solution to the disposal of radioactive waste, there are equally major difficulties (for example transport issues, which may be related either to the radioactive waste being carried or simply the number of vehicle movements, and the large volumes of waste that it might be necessary to accommodate). The RWMAC view is that the possibility is something the UK might seek to explore further although, in the Committee's view, without any great expectation of a successful outcome

Deferring or reducing the requirement ? The Select Committee also asked whether the UK could simply postpone the search for a repository and simply maintain existing arrangements. It also asked whether more emphasis on waste partitioning could get used to defer and/or reduce the requirement for a repository.

The RWMAC believes that current waste stores and packaging containment can cope with a further period of interim storage of at least fifty years. However, they have not been designed for the very long term. The RWMAC does not believe that partitioning, either to support decay storage (separating short-lived from long-lived ILW) or as a precursor to transmutation, can significantly aid the UK's radioactive waste management ask.

To reiterate, the RWMAC view remains that a policy of eventual deep disposal should be reaffirmed and arrangements for securing this at the earliest reasonably achievable date should be set underway.

Retention of expertise

Finally, the Select Committee asked what measures the UK should take to sustain the long-term research base for the management of its nuclear waste.

The RWMAC perceives that while it is desirable to retain the expertise, experience and intellectual property built up, for example, by Nirex, as far as is possible, this will not be an easy task. It is likely to require moves to generic (as opposed to site-specific) and international collaborative work.

Such retention will become more difficult the longer the UK repository development programme is suspended.

Concluding remarks

What I hope I have been able to do is to give you some flavour of how RWMAC views the past and the conclusions to be drawn from it. This analysis permitted the committee to formulate ideas for the future and these have been put to the Select Committee. Clearly there is a lot of work to do to fill in the detail.

The Committee's recommendations may not, of course, ultimately be accepted by the Government. In that event, the RWMAC will offer the best advice it can on the delivery of the waste management policy decided.

But whatever happens, it is hoped that Government neither, on the one hand, attempts to go round the same old circle that has led to failure in the past, nor, on the other, puts the whole issue on hold because of its perceived political difficulty.