On 20th April 2005 a fractured pipe was discovered in the Feed Clarification Cell of the Thorp Reprocessing Plant at Sellafield. The pipe is a feed pipe to a Head End Accountancy Tank and the fracture has led to a significant release of dissolver liquor to the Cell, leading to some corrosion of in cell steelwork. The liquor volume is around 83m3 of nitric acid containing dissolved irradiated uranium and associated plutonium and fission products.
There has been no exposure of workers and no abnormal discharge of radioactivity to the environment. The cell is designed to contain any spilled liquor and there is no evidence of any leakage from the cell. There is no risk of criticality in the cell and the situation in cell and on plant is stable.
A Board of Inquiry has been convened and is investigating the cause of the pipework failure along with a project group which has been set up to examine the failed pipework and to agree how the facility will recommence operations. Work is progressing well and recovery of the liquor is anticipated within several weeks.