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 January 2015 to 31 March 2015, there was one incident which met the MRC.
Ministerial Reporting Criterion - Dangerous occurrences reportable under the Nuclear Installations (Dangerous occurrences) Regulations 1965; that is to say-any occurrence on a licensed site involving the emission of ionising radiations or the release of radioactive or toxic substances in such circumstances as to cause or be likely to cause the death of, or serious injury to the health of, persons on the site at the time of the occurrence.
Shortly after midnight on 16 March 2015, EDF Nuclear Generation (NGL) declared a site incident at Heysham 1 Power Station. The incident was declared following the release to atmosphere of approximately 30 tonnes of clean Carbon Dioxide (CO2) from a failed pipe.
There was no immediate nuclear safety or radiological risk as a result of the event, but it has highlighted NGL's failure to adequately maintain its Carbon Dioxide storage and distribution system, which provides the coolant gas for the Heysham 1 reactors. Although no one was injured, CO2 is a substance that can be hazardous to health and the quantities released could have had serious implications if workers had been in the vicinity, including potential fatalities. ONR immediately commenced an investigation into the event and, on 25 March 2015, served an Improvement Notice on NGL for its failure to maintain its Carbon Dioxide storage and distribution plant at Heysham 1 power station. The improvements are required by 30 September 2015 and before the CO2 plant is allowed to return to service.
The two reactors remained operational at steady load during the event and continue to operate safely.