Whitehaven News

The Whitehaven News


Thursday, June 21, 2001

BNFL has been left with a 1 million bill due to the enforced shutdown of one of its Calder Hall nuclear reactors at Sellafield.

Reactor N.2 - 45 years old - had to be shut down for two months after experts came across what has been described "as some unusual features" in duct welding.

Safety was not at risk but the cost of the totally unexpected investigations piled on the financial agony for a company also having to bear the heavy costs associated with its Mox fuel data falsifications.

Because of the surprise finding BNFL were also instructed to carry out investigations on Calder One reactor to make sure there were no similar problems.

Reactor Two was already shut down for its annual maintenance checks in March when the fault came to light. These took five weeks but the reactor has just started to operate again, with a massive loss of production.

A BNFL spokesman said: "During this 'outage' some unusual features were detected in a weld associated with a reactor duct. The Nuclear Installations Inspectorate were immediately informed and a programme of work was drawn up to investigate further, and assure both the NII and ourselves that they were not indicative of any developing problem.

"The evidence of these investigations is that these features were present on the day the welds were made and have remained unchanged ever since. Overall reactor safety was not affected by the presence of these anomalies."

Calder Hall's station manager Peter Gallie revealed that the shutdown resulted in production loss of about 1,000,000 but added: "Safety is our top priority and the teams on the reactors have worked very hard to resolve this issue to the satisfaction of both ourselves and the regulator."

BNFL stresses that the reactor was kept shut down until everybody was satisfied before being brought back into production at the beginning of June.

And as a precautionary measure the ducts on Reactor 1 were also investigated and cleared during a two-week shutdown.

The NII's inspector for Calder Hall, Steve Lewis, confirmed it was not a safety issue.

The problem was in the material used to form the reactor's pressure vessel but was not load-bearing and did not affect the vessel's strength.

It was a design fault dating back to the reactor's manufacture in the 1950s.

"BNFL dealt with the problem successfully and quickly and then we asked them to check Reactor 1 as well."

Calder Hall has four reactors employing about 300 people but they are due to close in six years time.

All four reactors have to be given rigorous checks on top of the routine annual maintenance to make sure there is no safety threat.

Many of BNFL's major emergency exercises are based on simulated Calder reactor accidents.