The UK Atomic Energy Authority will spend at least £500m on two projects to clear up nuclear waste at Dounreay early next century.
One will involve dealing with the notorious shaft at the Caithness site, which holds over 1,000m3 of hazardous material, including pieces of spent nuclear fuel.
The UKAEA submitted two proposals to the Government late last year – one to recover the waste and the other to stabilise it in situ – and expects a decision within two months.
The cost of retrieving the contents of the shaft are estimated at £200m. An equivalent sum will need to be spent on building a plant to treat and package it.
This plant will also process the contents of a wet silo at Dounreay which holds nearly 700m3 of waste in water.
The UKAEA is committed to stop putting waste into the silo by 1999 and begin removing its contents shortly thereafter. The cost of this operation is put at £100m.
The organisation would not disclose estimates for the in situ confinement proposals for the shaft.