Assessments of the environmental impact of the Thermal Oxide Reprocessing Plant (Thorp) have not been carried out, according to Professor John Knill, chairman of the Radioactive Waste Management Advisory Committee.
BNFL had hoped to get the plant started before Christmas 1992, but is still awaiting permission from HM Inspectorate of Pollution. The company estimates that the delays are costing it pounds 2m a week.
The committee has been investigating BNFL's plans to bury plutonium- contaminated wastes from foreign countries at Sellafield rather than shipping them back to their country of origin. Although the committee submitted its conclusions last October and recommended that they be published, the Government has kept the report secret.
Professor Knill refused to divulge its contents but he conceded yesterday that 'the full range of evaluations has not yet been done. We have asked for them and have not seen them. It is necessary that this should be done before Thorp goes into operation.'
Instead of repatriating all the wastes that will arise from reprocessing overseas fuel at Thorp, BNFL wants to send back a smaller volume of waste but whose radioactivity is equivalent to that contained in the original fuel. This procedure, known as 'substitution', would greatly reduce waste transport costs and thus greatly increase the profitability of BNFL's operations.
Substitution means that wastes contaminated with plutonium and americium would have to be buried in Britain, at the repository which the nuclear waste disposal company UK Nirex is proposing to build deep underground near Sellafield. However, the Nirex repository is not yet built and the case that it can be safe in the long term has not been proven yet.
According to Professor Knill: 'The principle behind substitution is that it should carry no environmental penalty. But before you can say it is environmentally neutral, you need to know the safety case behind the deep underground repository.'
The committee, in its annual report which was published yesterday, questions whether the Sellafield site will be safe enough. It warned that, at present, 'it is an open question as to whether . . . the stringent hydro geological conditions required for a deep radioactive waste repository can be met at this site.'
The annual report warns that underground water - which would carry radioactive material dissolved in it - might be flowing vertically upwards from the site of the proposed repository into aquifers used as a source of drinking water. The radioactivity could re-enter the environment before it had a chance to decay to safer levels.
About 5,000 tons of spent nuclear fuel are being held in storage at Sellafield, pending approval for the start-up of Thorp. About two-thirds of the reprocessing over the next 10 years will be of fuel from overseas
A spokesman for BNFL said that the company's policy was for highly radioactive wastes to be returned to their country of origin as soon as practicable. 'Other options are worthy of study for less radioactive wastes,' he said.
Writing in the Independent on Monday, another member of the committee, Professor Andrew Blowers, called on the Government not to put Thorp into operation.
Writing in a personal capacity, he warned that 'if substitution takes place, the UK will be irrevocably committed to managing foreign waste in perpetuity. This prospect alone should be a major reason for the Government to abandon the project.'Reuse content