The o2.8 billion plant is designed to reprocess spent uranium oxide fuel from advanced gas-cooled reactors (AGRs) and pressurised water reactors (PWRs), extracting uranium and plutonium. It was completed in 1992, but commissioning has been stalled until radioactive discharges from the works have been authorised by HM Inspectorate of Pollution (HMIP) and the Ministry of Agriculture, Fisheries and Food (MAFF).
Draft authorisations were sent out for consultation last November (ENDS Report 214, pp 19-22 ). Over 64,000 of the 83,000 responses expressed opposition to the plant - and 58,000 called for a public inquiry to be held.
The first round of consultation was limited to the direct environmental impact of THORP and the rest of BNFL's operations. However, on 28 June Environment Secretary John Gummer announced that although "no point of substance" had been made which would cause HMIP and MAFF to reconsider their draft authorisation conditions, a second round of consultation would be held to address wider issues that had been raised but which fell outside HMIP's brief (ENDS Report 221, pp 29-31 ).
Chief among these wider objections is the fundamental justification for the plant. THORP won planning approval after the 1977 Windscale inquiry - but since then the arguments for the plant have dropped away one by one. Research into fast breeder reactors has ground to a halt, removing the main future market for plutonium. Similarly, reprocessed uranium is now considerably more expensive than the virgin material. Further doubts have spread over the waste management implications of reprocessing - indeed, many countries have already chosen to store their spent fuel in dry stores prior to final disposal (ENDS Report 214, pp 19-22 ).
The nature of the second consultation round has become clear with the publication of the consultation documents. These consist of a statement on Government policy on THORP, HMIP's report on the first round of consultation, further material on THORP's environmental impact, and a paper on the economic and commercial justification for THORP. The last two documents were supplied by BNFL.
Government support for the project has hardened in recent months. Launching the documents, it announced that it is now "minded" to authorise THORP - and does not consider that the wider issues of justification and economics are relevant to its decision. And "even if the wider issues had been relevant, Ministers would still have been minded" to give the go-ahead.
The Government's policy statement goes on to say that "there is a policy presumption that plants, such as THORP, which have been built in accordance with planning permission and meet the relevant technical and regulatory standards, should be allowed to operate."
Opponents of the plant have condemned the consultation as a sham. Certainly, it is hard to see what it will achieve if the authorities regard its scope as irrelevant to the final decision. A senior Department of the Environment official suggested that perhaps it will "give interested parties an opportunity to put up compelling reasons why THORP should not be commissioned."
The handling of the affair supports the view that the latest consultation is an attempt to head off Greenpeace's threat of a legal challenge. The group argues that the wider issues of justification, economics, nuclear weapons proliferation and alternative disposal routes can only be addressed at a public inquiry. Throughout, the Government has been careful not to rule out the possibility of an inquiry - but appears to be hoping that the latest consultation round will get it off the hook.
If this interpretation is correct, the strategy appears to have failed. Greenpeace has written to Mr Gummer warning that if he fails to call a public hearing by 31 August it will commence proceedings. The group's case is based on the requirement under official guidelines on the Radioactive Substances Act 1960 which say that "all practices giving rise to radioactive wastes must be justified, i.e., the need for the practice must be established in terms of its overall benefit."
ICRP principle disregarded
The guidelines stem from a key principle established by the International Commission on Radiological Protection (ICRP), and firmly endorsed by the Government over the years, that "no practice involving exposures to radiation should be adopted unless it produces sufficient benefit to the exposed individuals or to society to offset the radiation detriment it causes."
In its response to the first consultation, the official Committee on Medical Aspects of Radiation in the Environment (COMARE), backed by the Department of Health, pointed out that no estimate of this "detriment" had been made. COMARE warned that uncertainties in discharge estimates and biological models meant that it could not be sure that the dose to "critical groups" in the population would be below recommended limits. It also refused to rule out the possibility that the increased discharges "could result in an increased risk to the general public living in Seascale".
Despite these concerns, Mr Gummer says he is satisfied that the terms of the authorisations "would effectively protect human health, the safety of the food chain, and the environment generally." But there is no evidence that the ICRP principle requiring a cost-benefit analysis has been followed.
The issue of detriment to the environment is still not settled, but the Government's case is equally compromised in its assessment of THORP's benefit to society. As other justifications have been discredited, the debate has focussed increasingly on the potential financial benefits of operating THORP.
BNFL's economic case
The only information provided on this matter has come from BNFL, in the form of edited highlights of a report by management consultants Touche Ross commissioned by the company. This claims that in its first ten years' operation THORP will make some o1.8 billion for BNFL, and some o900 million for the UK, when compared to the options of returning fuel to customers or retaining it at Sellafield for storage and eventual disposal. The Government says that it "sees no reason to dissent" from BNFL's cost projections, and has no plans to commission an independent analysis of the findings.
However, as the Government has refused to require the publication of the full Touche Ross report it is hard to assess the reliability of BNFL's figures. Even the edited version reveals at least one major flaw. If THORP was blocked, it is highly likely that BNFL would offer a replacement fuel management service based on constructing dry stores, either at Sellafield or in the country of origin. The report includes the costs of building replacement storage facilities - but fails to allow for any income that BNFL would receive from providing such a service to its overseas customers.
Other inconsistencies emerge. In recent months BNFL has claimed, with backing from Energy Minister Tim Eggar, that scrapping THORP would expose it to compensation claims from customers of up to o5 billion. The company's report lowers this to o4 billion - and then makes the crucial admission that there is "robust legal protection in the contracts" against such claims.
Another key issue to emerge from BNFL's document is that over 90% of the AGR fuel in storage at Sellafield has already been dismantled in preparation for reprocessing. BNFL's cost estimates for the dry storage alternative include an undisclosed sum to cover new facilities to prepare this dismantled fuel, some of which has already started to corrode.
Greenpeace is "very concerned" to learn of this dismantling, and is demanding to know how it was authorised and justified. ENDS understands that the process was authorised by the Nuclear Installations Inspectorate in 1987. Greenpeace is likely to argue that the granting of permission to dismantle the fuel was prejudicial to the final decision on THORP.
Friends of the Earth has suggested that both BNFL and its customers would actually be better off if THORP was scrapped in favour of storage. Customers would avoid the costs for storing plutonium and reprocessing waste, and BNFL would avoid incurring some o3.2 billion in operating and decommissioning costs. The Government is dismissive of the scenario, arguing that if customers felt this way, "it would be possible for them, collectively if necessary, to make BNFL an attractive offer not to operate the plant."
ENDS understands that the terms of the contracts are already favourable towards BNFL - so it is hard to see why customers should volunteer to pay even more simply to persuade BNFL to switch to a cheaper waste management option. Equally, while BNFL is well protected by the contracts, its customers are believed to face substantial penalties if they withdraw.
The Government's repeated policy that "it is for the owners of the spent fuel to make their own commercial choices as to whether to reprocess" seems rather inadequate to cope with this deadlock. However, the Government "sees no wider policy reasons" for initiating a renegotiation of the contracts.
Shift away from reprocessing
Meanwhile, it is clear that despite public expressions of support, BNFL's customers are increasingly viewing THORP as a short-term option for their spent fuel. Japan - the only country with an active fast breeder programme - is building its own reprocessing plant which will remove its reliance on BNFL within ten years. Germany, the other main overseas customer, is redrafting its radioactive waste legislation to make dry storage a permissible option.
In the UK, Scottish Nuclear is awaiting a planning decision on a dry store at its Torness station and is now looking to build a similar store at Hunterston. If these stores are built, the company expects to save o45 million per year - a reduction in spent fuel management costs of over 50%. THORP will only be used to process wastes arising before 1996.
Similarly, Nuclear Electric is moving away from reprocessing. Waste from its Sizewell B PWR will be stored on site. The company admits that its existing policy for AGR fuel is based chiefly on an "attractive commercial package", under which its contract for THORP is explicitly linked to the ongoing reprocessing of the company's Magnox fuel.
THORP's unwanted product
Yet neither of the UK nuclear utilities has any plans to use THORP's products. According to Nuclear Electric, the uranium arising from reprocessed AGR fuel is contaminated with neutron-absorbing isotopes, and so needs an unusually high level of enrichment. This makes it more costly than virgin fuel. Similarly, neither company is taking seriously the option of using mixed oxide (MOX) fuel - BNFL's suggested method of burning up recovered plutonium.
BNFL is now seeking planning permission for a commercial plant at Sellafield to produce 100 tonnes of MOX per year. The company is convinced that demand for this fuel will rise - though its reasons are far from clear. MOX is considerably more expensive and radioactive than conventional fuel, and existing stations can only accommodate a small proportion of MOX in their fuel. But BNFL's hopes for the fuel vividly illustrate the circular logic that underpins THORP. If customers choose to burn MOX, it will simply be because it is the least expensive way of managing unwanted plutonium arisings - yet that could have been avoided in the first place.
The consultation period ends on 4 October, and the Government hopes to reach a verdict by the end of the year. BNFL says that each week of delay is costing it over o2 million - and has been pressing for permission to begin commissioning tests.
Challenge on commissioning tests
In July, HMIP and MAFF announced that they were "minded" to let BNFL begin its commissioning tests, and confirmed the decision on 25 August. These tests, which would partially contaminate the plant with depleted uranium, were blocked last November. The change of stance reflects the increasing likelihood that THORP will now get the green light.
HMIP has now varied Sellafield's existing consents to allow the testing to start on 2 September. If THORP is eventually blocked, BNFL will be required to meet the o250,000 bill for decontamination. Greenpeace claims that the announcement prejudices the consultation process. As ENDS went to press, the group was seeking an injunction to halt the commissioning and also applying for a second judicial review.