A statement on incidents at nuclear installations in Britain and during the transport of radioactive material which meet Ministerial Reporting Criteria (MRC), is provided to the Secretary of State for the Department of Energy and Climate Change and the Secretary of State for Scotland, and is published each quarter by the Office for Nuclear Regulation.
For the period, 01 July 2014 to 30 September 2014, there was 1 incident which met the MRC.
During a routine inspection by EdF Energy Nuclear Generation Ltd (NGL) on one of the boilers at the Heysham 1 Reactor 1, NGL identified an unexpected crack near an important weld. The area of the failure is called the boiler "spine"; an item that provides support to the boiler.
There has been no release of radioactive material and no persons have been injured.
EDF has taken the decision to shutdown the similarly designed reactors at the Heysham 1 and Hartlepool sites. Inspections are currently being undertaken on all of the boilers in each of the reactors at Heysham 1 and Hartlepool and equipment is being fitted that will enable monitoring of the condition of the boiler spines.
Although inspections continue, a number of boilers have already been inspected and no further cracks have been identified.
Investigations into the cause of the crack continue.ONR will require acceptable safety cases from EDF Energy before granting permission for the planned return to service of these four reactors.