The Nuclear Decommissioning Authority

26 April 2012

One of Wylfa’s twin reactors ceased generating electricity yesterday after 41 years of safe operation. Originally planned for the 30th April, the reactor shut down five days earlier than planned after an issue was identified with the plant.

Normally, the reactor would have returned to service within a few days following an investigation. The decision has been taken, however, not to restart the reactor due to the closeness to the scheduled shutdown date.

The reactor’s turbines first synched with the grid in 1971 and have produced over 224TWh (terawatt hours) of electricity in its lifetime – the equivalent to two-thirds of the UK’s total electricity demand in a year.

The decision to finally close one of the site’s two reactors was taken proactively by the site’s operator, Magnox Ltd (a company owned by EnergySolutions) because limited fuel stocks do not allow both reactors to continue to operate. Wylfa received the final Magnox fuel delivery back in December 2011.

Efforts will now focus on optimising generation on Reactor 1, which is allowed to operate until 2014. Assessing Magnox's request and safety case, the Office for Nuclear Regulation (ONR)'s decision on permissioning the transfer of partially used fuel from Reactor 2 to Reactor 1 is expected in the summer.

Stuart Law, Wylfa Site Director, said:

“Today was a significant milestone in Wylfa’s history. Although it is the end of an era, we must now focus our efforts on safe generation with Reactor 1.”

Brian Burnett, Head of Programme for the Nuclear Decommissioning Authority, which owns the site, said:

“Wylfa has a long and proud history of safe electricity generation. The income it has generated has made an important contribution to our mission of decommissioning the UK’s first generation of civil nuclear sites. We continue to support Magnox in its efforts to optimise generation from the remaining reactor.”

Richard Waite, President, UK and Europe at EnergySolutions said:

“The 40 plus years of safe generation at Wylfa is a testament to the skill and dedication of the Magnox workforce and my congratulations go to all those, past and present, involved in its success. The life extensions secured at Wylfa and Oldbury were significant achievements and we are confident there is more to come at Wylfa, as we continue to generate both additional revenue for the NDA and clean power for the UK.”

Wylfa is the only Magnox site still generating electricity, following the closure of Oldbury Power Station on 29 February 2012. It is also the largest and last reactor of its type to be built in the UK.