The reactor was expected to return to service today, but by Wednesday afternoon National Grid data showed zero output from the site. The return of Wylfa-1 has been delayed twice already, but the Magnox spokesman said the company expects the reactor to return to service on Thursday.
The Wylfa-1 reactor is the oldest nuclear unit in the UK, and has already been granted a four year life extension, but Magnox hope to have its lifetime extended again until 2015.
However, power market traders speculated that the high cost of repairing and maintaining the aging plant might make it uneconomic to continue to run.
“It depends on whether it’s worth the investment to fix it,” the trader said.
The unit came to a standstill last week when a turbine in reactor one experienced a steam leak just two days after the generation site had re-opened following a five month period of maintenance work.
But the company spokesman brushed off any suggestion that the plant may no longer be economic to run, saying that all problems that the unit has encountered have been quickly fixed.
If the Office for Nuclear Regulation does not approve the extension, the plant will need to close this September. The approval would extend its lifetime until the end of 2015, the spokesman said.