CLAIMS BY the nuclear industry of a fourfold reduction in the radioactivity of reactors over 85 years do not add up, a new report said this week.
The report, by independent nuclear engineer John Large, criticises the approach of British Nuclear Fuels (BNFL) to its 85 year long 'safe store' programme.
This involves removing fuel from the reactor and then allowing the core and its containing structures to stand for 85 years. BNFL says radioactive decay will reduce enough to allow direct worker access to the core.
Safe store ahead of future demolition will enable work to be carried out more quickly and cheaply than using remotely controlled robotic equipment now.
BNFL, which owns most of the UK's ageing magnox reactors, recently submitted evidence supporting its safe store strategy to the Magnox Decommissioning Dialogue Timescales Working Group, run by the Environment Council (EC).
However, BNFL's calculations do not take account of the wide variation in the decay rates of different materials, says Large.
Some isotopes will remain active, he says.
NCE understands BNFL has applied to amend and re-submit evidence to the EC.