EDF Energy’s Sizewell B nuclear reactor is not affected by any of the flaws detected in the reactor pressure vessels (RPVs) of similar reactors in Belgium and France, Britain’s Office for Nuclear Regulation (ONR) said on 3 June.

Sizewell B has one pressurised water reactor with two turbine generators which has been offline since April for a statutory outage. During that time, EDF Energy examined the reactor to make sure it is in good condition. ONR is "satisfied that they demonstrate the continued integrity of the reactor pressure vessel and that the hydrogen flaking present in the Doel 3 and Tihange 2 reactors in Belgium is not evident at Sizewell B", it said in a statement.

Electrabel’s Doel 3 and Tihange 2 reactors were shut down in 2014 after hydrogen flakes were found in the walls of the reactor tanks. They were restarted last year, but Germany has called for them to be shut down again after its independent Reactor Safety Commission advised it could not confirm the reactors would be safe in the event of a fault.

ONR added it had reviewed reports that demonstrate Sizewell B reactor pressure vessel domes are not affected by a carbon segregation issue, subject of scrutiny at unit 3 of France’s Flammanville NPP. Last year, the French nuclear regulator Autorite de Surete Nucleaire said serious anomalies had been found in a reactor vessel at EDF’s Flammanville 3 nuclear reactor.