HSE announces conclusions on continued operation of Wylfa Nuclear Power Station

HSE Press Release: E138:04 - 4 October 2004

The Health and Safety Executive's Nuclear Installations Inspectorate (NII) has completed its independent assessment of the Periodic Safety Review (PSR) undertaken by Magnox Electric plc for the Wylfa nuclear power station.

On the basis of this assessment, the safety improvements Magnox Electric has made at Wylfa and a follow-up programme, NII has concluded that there is an adequate basis to allow continued operation of the reactors up to the company's declared end of generation in 2010 and subsequent final defuelling of the reactors, subject to continued satisfactory performance.

Nuclear licensees are required to carry out PSRs as a condition attached to their nuclear site licences and to satisfy NII that their sites remain adequately safe for continued operation. Topics addressed by these reviews include reactor pressure circuit and internals, fault studies and probabilistic safety assessment, human factors, internal and external hazards and radioactive waste management.

Safety improvements already implemented by Magnox Electric at Wylfa in the last twelve months are in line with the intent of the PSR requirements and build on other improvements made since the Long Term Safety Review for the station (see Notes for Editors). They include post trip cooling enhancements, the addition of a back-up feed system and improvements to enhance protection against hot gas release.

The main elements of the follow-up programme are:

• An annual review of the graphite safety case by the licensee;
• Maintenance of satisfactory progress on continuing improvements; and
• Demonstrating continued satisfactory results from the regular test and inspection programme that underpins the normal operation of the station.

Notes to editors

1. Wylfa nuclear power station is situated on Anglesey, North Wales.

2. Wylfa is the last of the UK Magnox design of stations and incorporates a pre-stressed concrete pressure vessel with a steel membrane liner. The pressure vessel contains a graphite core and the fuel is uranium in the form of metal rods contained within magnesium alloy (Magnox) cans. Cooling of the core and the fuel is provided by CO2 gas. Wylfa commenced operation in 1971.

3. The Wylfa PSR is a continuation of a series of reviews at all nuclear licensed sites. These reviews are carried out every ten years, in line with international practice. This represents the first PSR for Wylfa and follows on from the Long Term Safety Review completed in 1994. The results of previous PSRs for Magnox stations have been announced in press releases, the last of which covered Oldbury in 1998.

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