Office for Nuclear Regulation

Fourth quarter 2009 statement of nuclear incidents at nuclear installations

A statement on incidents at nuclear installations in Britain which meet Ministerial reporting criteria is reported to the Secretary of State for the Department of Energy and Climate Change and the Secretary of State for Scotland and is published every quarter by the Health and Safety Executive.

For the period 1 October 2009 to 31 December 2009 there were no incidents at nuclear licensed installations that met the reporting criteria.

For the period 1 July 2009 to 30 September we said there was one incident that may meet the reporting criteria. An update on this is below.

Sellafield Ltd - Capenhurst

Sellafield Limited - Capenhurst Works reported on 24 July 2009 the leakage of radioactive liquor from one of the uranium hexafluoride ("Hex Tails") cylinders, currently stored inside a building.  The leak was discovered during routine plant surveillance.  The hole in the leaking cylinder was promptly sealed by the site fire brigade. Subsequent investigations determined that the amount of radioactivity in the leaked liquor was in excess of column 4 schedule 8 of the Ionising Radiations Regulations 1999, which resulted in the event meeting the reporting criteria.

There was no significant personal radiation exposure or contamination and no release to the environment of airborne radioactivity.

The licensee promptly removed the majority of the radioactive contamination from the floor of the building.  The sealed cylinder is being monitored within a bunded area inside the building pending more work to secure the safe emptying and autopsy of the cylinder to determine the cause of the leak.  Testing of other similar stored cylinders has been undertaken to assess the integrity of those cylinders.

NII will continue its investigation once the autopsy work has been completed to determine the cause of the event and to decide if enforcement action is warranted.

Single copies of statements are available free from the Health and Safety Executive, Nuclear Directorate, Division 4, Building 4.N2, Redgrave Court, Merton Road, Bootle, L20 7HS,