Just weeks after handing over the THORP reprocessing plant to the Nuclear Decommissioning Authority (NDA) on 5th April 2005, BNFL has confirmed that leaking pipes in the Head-End section of the plant, where fuel is sheared and dissolved in nitric acid, is likely to keep THORP out of action ‘for weeks, if not months’.
Managing Director of the Sellafield site Barry Snelson has said “I have asked for the front end of the plant’s reprocessing operations, including shearing, to be closed down. The plant is in a safe, quiescent state”. The NII has been informed and will be carrying out its own investigation of the leak.
Whilst details of the incident remain sketchy as yet, the leak and pipework involved is located in THORP’s Feed Clarification Cell through which the already dissolved oxide fuel, in highly radioactive liquor form, is fed on its way to the Chemical Separation area of the plant. In 1998 leaking pipes in the same area of the plant resulted in an almost 5-month closure [see CORE Briefing 11/98].
The current closure will not be good news for the NDA who were counting on the revenues from a fully operational THORP ‘asset’ to help offset Sellafield’s clean-up costs for the current and future financial years. Whilst BNFL/NDA have refused to divulge an individual revenue figure for THORP, the total revenues expected from all comercial operations at Sellafield have been put at around £800M. The unquantified THORP revenue component for 2005/06 is already at some risk by the refusal of one German customer to pay its dues because of BNFL’s failure to reprocess the customer’s fuel on time [see CORE Briefing 5/05].
Now in its 12th year of operation and at least two years behind schedule, THORP has reprocessed a total of 5644 tonnes of oxide fuel from an initial 10-year (Baseload) target of 7000 tonnes. Last year, largely as a result of the extended failure of an evaporator in the High Level Waste complex, THORP fell 125 tonnes short of the 725 tonne target published in BNFL’s ‘Near Term Work Plan’ for Sellafield. For 2005/06 the work plan projects that THORP will reprocess 772 tonnes of oxide fuel though this is clearly now unachieveable as a result of both the current leak and the continuing restriction put on the plant’s annual throughput by the failure of Sellafield’s Vitrification plant to operate to specification.