LONDON (Reuters) - EDF Energy will be allowed to restart a reactor at its Hunterston plant in Scotland where cracks were found last year, for an initial four month period, Britain’s nuclear regulator said on Tuesday.
The Hunterston B nuclear plant on the west coast of Scotland is more than 40 years old and when operating can provide enough electricity to power more than 1.7 million homes.
It has two reactors, so called reactors 3 and 4, which were both taken offline last year after cracks were found on the graphite core during routine inspections at the facility.
Before either reactor could restart EDF Energy had to provide safety cases to the Office for Nuclear Regulation (ONR) to show they would be safe to operate even in the unlikely event of an earthquake.
“ONR is satisfied that Reactor 4 is safe to operate for the next period and can be safely shut down in all foreseeable circumstances, including that of a significant seismic event,” the regulator said in a statement.
The reactor will be allowed to operate for 16.025 terawatt hours, or approximately 4 months.
“Whilst we are content to allow operation for a limited period, the longer term condition of the reactor remains uncertain and the licensee will need to justify safe operation beyond this period,” the ONR said.
EDF Energy, British arm of France’s EDF, said it had invested more than 125 million pounds ($151 million) in research into the operations of the graphite cores used in most of its UK reactors.
“We have demonstrated that even in the most extreme conditions our reactors operate within large safety margins,” EDF Energy said in a statement.
The ONR said it would also start reviewing whether the other reactor at the plant can restart.
Reporting by Susanna Twidale; editing by Jason Neely and Jane Merriman