Reprocessing of spent nuclear fuel for Japanese and European customers forms a mainstay of BNFL's operations at Sellafield. Contracts with such customers require recovered materials and radioactive waste products to be returned to the country of origin.
BNFL has been keen to meet these obligations through waste "substitution", in which overseas intermediate level waste (ILW) is disposed of in the UK and much smaller quantities of high level waste (HLW) are returned instead. Environmental groups have claimed that the plan will make the UK the "dustbin of the world".
In 1995, a White Paper concluded that ILW substitution was dependent on progress towards a waste repository in the UK (ENDS Report 246, pp 31-33 ). This policy was left in tatters in 1997, when Nirex failed to win planning permission for work leading towards an ILW repository at Sellafield (ENDS Report 266, pp 13-14 ).
The Government is now half way through a consultative programme to develop a long-term strategy for ILW, HLW and other radioactive wastes (ENDS Report 320, pp 41-42 ). However, it commissioned NAC International - a consultancy which numbers BNFL among its clients - to assess the case for permitting ILW substitution in advance of any agreed way of dealing with the waste. The DTI now appears minded to accept the consultant's recommendations.
NAC concludes that the environmental consequences of substitution would be "negligible" if overseas ILW is eventually placed in a repository in the UK, and "very small" if long-term surface storage is pursued. It says that the quantity involved - the volume of four detached houses - represents only 1.4% of the total UK inventory of ILW, and that the environmental impact would be small regardless of the method of calculating radiological equivalence between ILW and HLW.
The main attraction of substitution is financial. NAC says that the total benefit to the UK could be £200-650 million, while overseas customers would avoid expenditure on ILW handling, storage and disposal facilities.
BNFL's reprocessing business will shortly be transferred to a new Nuclear Decommissioning Authority - and the DTI says that the savings from substitution will help the Treasury to foot the organisation's massive bill for nuclear clean-up activities.
Moreover, NAC says that substitution would reduce the number of international waste transports by ship and rail from about 225 to 38. It argues that this should minimise international opposition, even though the waste being moved will be more hazardous.
Substitution would also speed up the process of returning wastes. BNFL says that HLW returns could start within a year or so. However, NAC says that if substitution is not permitted, ILW shipments could not start until 2013-15, and could take up to 24 years to complete.
The precise timing of ILW returns is, however, dependent on the interpretation of the contracts. These require return of the waste 25 years after it is generated - but BNFL claims that this time window does not start until it has completed "baseload" reprocessing in 2007-8, meaning that ILW shipments could extend to 2033 and beyond.
The move to allow substitution is certain to arouse a hostile response from environmental groups. They are unlikely to be convinced by NAC's arguments that substitution will not extend the operating life of the controversial THORP reprocessing plant, and that it does not breach the principle of self-sufficiency in dealing with nuclear waste.
One of the key principles of radiological protection, established by long-standing international agreement, is that no practice involving exposures to radiation should be adopted unless it produces sufficient benefit to society or the individuals affected.
Environmental groups have used this justification requirement as a major weapon in their campaign against the nuclear industry.
In 1994, the High Court rejected Greenpeace's challenge to the controversial THORP reprocessing plant. However, it ruled that a 1980 Euratom Directive required that justifications was needed on a site-by-site basis before an activity could be authorised (ENDS Report 230, pp 43-44 ).
Since then, the most prominent debate over justification concerned BNFL's MOX fuel plant. Environment groups again challenged the justification for the plant in the courts, largely on the grounds that the Government's case ignored very large sunk costs (ENDS Report 323, pp 54-55 ).
In 1996, however, the Euratom Directive was replaced with a new Directive. According to the Government, this "clearly requires a generic, rather than a site-specific, assessment of justification". In 2000, the Government moved towards this interpretation by placing generic justification decisions in England and Wales in the hands of the Secretary of State rather than the Environment Agency.
In late January, the Environment Department consulted on a new framework to implement the 1996 Directive and formalise future decisions on justification.
DEFRA proposes to a "one-stop shop" in which justification decisions would be taken jointly by the Westminster Government and the devolved administrations. It will create a central register of applications and determinations.
Any "new class or type of practice" which was not carried out before 13 May 2000 will need to be justified. Transitional arrangements will mean that some generic decisions taken since then - including the controversial approval for MOX - will stand.
"Existing" practices will be regarded as already justified. The regulation will allow anyone to apply for a review whenever "new or important evidence" about the efficacy or consequences of such practices comes to light.
However, DEFRA has yet to explain how it will define a a "new" practice. At one extreme, a new programme of nuclear reactors could be nodded through on the basis that nuclear power is an "existing" practice. On another interpretation, any new reactor design might need to be justified. ENDS understands that an advice note will be issued later this year setting out broad-based categories of existing practices.
A variety of regulators, including the Environment Agencies, the Health and Safety Executive, the Food Standards Agency and trading standards officers will oversee the system. They will be able to serve a contravention notice prohibiting operators from operating an unjustified process. Failure to comply will be a criminal offence.
During the row over the MOX plant, the Environment Agency urged the Government to legislate to ensure that justification is secured before construction begins and costs are sunk. However, DEFRA's consultation is silent on the matter.