Sellafeild’s Thorp reprocessing unit to shut down for seven months for planned maintenance

Atomanlegget Sellafield

Publish date: June 7, 2009

Written by: Charles Digges

Sellafield’s Thorp reprocessing facility will be shutdown by the site’s operator for seven months for “planned engineering and maintenance” while workers at the site check one of the three evaporators that feed the plants that reprocess spent nuclear fuel, officials said.

Environmentalists who have been pushing for the sites closure following a 2005 leak of radioactive liquor in Thorps clarification cell, were mildly encouraged the site would be out of commission for some time, but also disappointed that an eventual restart is planned.

There will be no impact the site’s 1,500 workers who will remain working while the engineering evaluations progress, said Sellafield, Ltd, the site’s operator, in a statement.

The main thrust of the work will focus on Evaporator C, one of three units at Sellafield that condense highly radioactive liquid.

The high level waste streams from the Thorp and Magnox Reprocessing facilities are fed to storage tanks via evaporators that concentrate the waste liquid, reducing storage volumes and providing a feed stock to the Waste Vitrification Plant, Sellafield, Ltd, the site’s operator, said in a statement.

Late last month, Sellafield workers found a fault in Evaporator B, which led to a staff-initiated shut down occasioned by an excess of activity in the evaporators upper coils .

Sellafield, Ltd,, said that the 50-year-age of the unit had led to a build up of activity in the evaporator and that it was not the result of any technical deficiency discovered in the equipment.  Evaporator B is currently working at full capacity.

Yet, environmental groups, particularly Bellona, which has worked with Sellafied for many years to improve its safety, have nonetheless called for the permanent closure of the Thorp reprocessing facility.

Speaking about the closure of Evaporator B late last month, Bellona nuclear physicist Nils Bøhmer said the age of the facilities involved make them very difficult to run safely.

“This latest incident (with Evaporator B)  is another nail in the coffin for the Thorp facility,” said Bøhmer.

“This incident shows exactly that – this is not a top notch facility but an old one that needs lots of maintenance,” he said.

Sellafield, Ltd. in announcing the closure of Evaporator C has taken care to disassociate it from the closure of Evaporator B, and indicated that the shut down of the C unit had been planned for months, and that it closure is related to a planned shutdown to carry out assessments and reapply for the Evaporator’s operational licence from the Nuclear Installations Inspectorate.

“Recent media speculation surrounding the future of  Thorp has focussed on Evaporator B which was taken temporarily off-line as a precautionary measure after an operational anomaly,” said Sellafeild, Ltd.

“The planned engineering shutdown in Thorp is not related to what happened with Evaporator B and we are disappointed that a planned maintenance period is being presented as a closure that threatens the future of the plant and its workers,” the group said.

Sellafield, Ltd. continued to say that Evaporator C is in good working condition and will continue to operate over the next  month to complete Thorp’s current efforts to reprocess 300 tonnes of spent nuclear fuel.