RWMAC's Advice to Ministers on the Radioactive Waste Implications of Reprocessing

10. CONCLUDING REMARKS

This review of the waste implications of reprocessing is different from the normal requests for work received by RWMAC, which usually ask for specific recommendations on a particular issue. However, the Committee recognises that UK policy on reprocessing will ultimately need to take into account a number of factors, some of which lie beyond its own remit.

Magnox reprocessing appears to have been effectively time-limited to around 2012 by BNFL’s revised Magnox business plan statement of May 2000. Closure of Magnox reprocessing is dependent upon the prior closure of Magnox reactors. However, RWMAC has questioned in this report whether, in light of the operating lives now foreseen for the remaining Magnox reactors, BNFL will be able to complete, in its B205 reprocessing facility, the reprocessing of all of the Magnox spent fuel that will have been generated by around 2012. Quite simply, the reprocessing throughputs achieved in the recent past coupled with the age of the facility call this into this question. It is for this reason that RWMAC has suggested that BNFL review its plan in this light and, in particular, declare what its strategy would be if the requisite throughput cannot be achieved. Given the sensitivity of the reprocessing issue, it is important that unrealistic expectations are not raised.

The lifetime of THORP reprocessing is dictated by BNFL’s ability to win commercial contracts for reprocessing either in the UK or abroad. RWMAC’s analysis suggests that currently contracted work would be completed by 2010. Statements made by British Energy to the House of Commons Select Committee on Trade and Industry suggest it will be difficult for BNFL to win new business within the UK. Recent developments abroad suggest that the acquisition of new overseas work will also not be easy. Indeed, some utilities both in the UK and abroad have indicated a wish to curtail existing reprocessing contracts although, as of the time of preparation of this report, none have actually done so. Hence, whilst the Committee was in no position to judge whether or not new overseas contracts might emerge, it notes the possibility that THORP reprocessing may also be a time-limited activity.

BNFL’s May 2000 business plan speculates on the possibility of the lives of the Oldbury and Wylfa Magnox reactors being extended through the use of Magrox fuel. The company envisages a decision on whether this is feasible sometime around 2003. In light of the above, it would seem sensible to contemplate this on the possible basis that THORP may no longer be operating, and that the spent Magrox fuel would need to be stored, as opposed to reprocessed.

RWMAC’s approach to this study has been to consider the full range of materials that would ultimately be held as a result of the reprocessing strategy in question, irrespective of whether they are formally regarded as resources or wastes. The reason for this is that they all have management and cost implications. This is the way RWMAC believes future policy development should address the issue. There need to be clearly-formulated, fully-justified and publicly-stated plans for all categories of materials: HLW (vitrified), HLW (spent fuel), ILW, LLW, reprocessed uranium and separated plutonium.

The effects of Magnox and THORP reprocessing will be limited on the amounts of ILW and LLW that the UK eventually has to manage. However, there will be more important impacts on the relative amounts of HLW, reprocessed uranium, separated plutonium and spent fuel that will need to be dealt with. These have been set out in this report. But to be clear, the difference will be in the relative amounts, rather than the spectrum, of materials that need to be dealt with. Substantial stocks of all the resulting materials already exist.

A particularly sensitive issue is the UK’s growing stockpile of separated plutonium on which a number of authoritative bodies have commented in recent years. The present study suggests that the eventual stock from the current UK nuclear programme will be of the order 120 t of plutonium oxide (allowing for BNFL’s revised Magnox business plan). RWMAC’s position remains³⁵ that there can only be a limited use for the stock in the foreseeable future, and the remainder of the plutonium should be declared a waste unless a credible reason for doing otherwise can be given. However, in this context, halving the amount held for future strategic purposes would not, in practice, halve the risk or management requirement. The Committee’s main call is for policy clarity in light of reasoned debate of the issues, and hopes this will be forthcoming as part of the Government’s radioactive waste management policy review.

Because of contracts with overseas customers there is inevitably handling of overseas spent fuel and reprocessing products in the UK. RWMAC believes that generally there is a lack of transparency in respect of this concerning the holdings of overseas material within the UK and the proposed schedule for, and progress made towards, their return. This can only encourage criticism that the UK is in effect a nuclear dumping ground. It is for this reason in particular that RWMAC sees such transparency and monitoring of declared policy and intent for the return of overseas materials to be important.

Reprocessing gives rise to radioactive discharges. The current work has shown that doses from these discharges, even to critical groups, are, under normal operations, well within the internationally accepted dose limit for members of the public, of one millisievert (1,000 microsieverts) per year. The Government’s recent UK radioactive discharge strategy consultation document² notes that doses to the local Sellafield critical group have fallen from about 2 millisieverts per year in 1981 to a current level of less than 0.2 millisieverts (200 microsieverts) per year.

But, in practice, this may not be sufficient reassurance for some groups of the public, who may look to historical problems or possible future abnormal occurrences or accidents in formulating a view. Seeking to continue to apply downward pressure on radiation doses, through application of the ALARA principle, continues to be important, although the definition of this principle³ acknowledges the need for a balance between radiological and other factors, including social and economic considerations. Worker dose is one of the factors that need to be taken into account.

RWMAC has argued the case for seeking to produce a full and operational definition of the concept of passivity in earlier sections of this report. The Committee believes that, as well as being important from an operational and regulatory point of view, it could also potentially provide an important means of providing additional reassurance to the public. However, the Committee acknowledges that this may not be easy in practice given possible considerations of not foreclosing future options for the management of materials. More consideration therefore needs to be given to this issue. But the earliest practicable reduction of HAL stored on the Sellafield site to appropriate buffer levels is clearly key in this context.

RWMAC welcomes the issue of the UK Strategy for Radioactive Discharges 2001-2020 Consultation Document² and the Ministerial guidance to the environment agencies on the regulation of discharges that it understands will follow. The Committee has argued for a number of years now (see, for example, reference 36) that the principles behind the regulation of discharges needs to be made clearer for the benefit of those who are required to apply them, those who are regulated and the public whom it is designed to protect and are expected to participate in consultation exercises. The Committee will be responding in detail to the consultation document in due course and is likely to welcome, in particular, the central emphasis that appears to have been put on critical group dose, through the criterion that by 2020 no member of the public should receive a dose in excess of 0.02 millisieverts (20 microsieverts) per year as a result of authorised discharges. As section 7.1 has shown placing a different emphasis on different measures can lead to different conclusions concerning the radionuclides that are most important, but it is the dose to an individual that is the most important determinant of health impact.

Finally, the Committee believes, there are a number of important issues that have been raised in the course of this report that BNFL might usefully consider taking on board as indicators of their future operational performance. These include: progress with Magnox reprocessing so as to allow closure of B205 by around 2012; progress towards the achievement of passive storage of materials (assuming a suitable operational definition can be agreed with the regulator); progress with the reduction of HAL stocks; progress with the return of products from overseas reprocessing, progress with reducing discharges so as to meet OSPAR objectives (including identification of needs and progress towards development of any necessary abatement technology); explanation as to how any new THORP contracts will be allowed for in this overall picture (given, for example, that it could place additional pressure on vitrification lines and add to or extend discharges). Clear and specific annual reporting against these kinds of indicators by BNFL is therefore recommended by RWMAC.