Wylfa nuclear plant’s 2015 extension to help meet winter demand

The UK’s oldest nuclear reactor might otherwise have been taken offline at the end of this year, in a winter already dogged by nuclear outages, but the regulator said its “comprehensive assessment” of the site revealed “no issues of nuclear safety significance” that would derail the operator’s plans to run the unit a year longer.

Utilities analysts at Citigroup said the extension could help offset the recent loss of a quarter of EDF Energy’s nuclear fleet due to concerns over the boiler design of its Heysham-1 and Hartlepool plants.

The unexpected loss of 2.5 GW of nuclear capacity could result in the UK’s capacity margins falling to half what was expected for this winter, which prompted National Grid to open a tender for supply-side contracts last month in order to guard against the risk of blackouts.

EDF Energy plans a “phased return” of its units between the end of October and the end of December 2014 although further delays remain a possibility.

Wylfa’s safety review took into account a ten year period from 2014 and found that generation could continue at the site for another year, with early defueling and decommissioning work to follow until 2024.

The ONR’s deputy chief nuclear inspector Mark Foy said: “Although the periodic review will not be considered complete until the licensee has delivered an agreed programme of work to address certain areas identified for improvement, our assessment has identified no issues of nuclear safety significance that could impact power generation at Wylfa to the planned end date of December 2015, and the subsequent defueling and early decommissioning operations until 2024.”