The Office for Nuclear Regulation (ONR) can confirm that EDF Energy Nuclear Generation Ltd (EDF Energy) has complied with an improvement notice.
The incident at Heysham 1 Power Station in Lancashire occurred on 23 December 2023, while Reactor 1 was being returned to service when a valve controlling the flow of superheated steam from the reactor failed, resulting in a steam leak.
Nobody was injured as a result of the incident, and there was no risk to nuclear safety, the public or the environment.
Mike Webb, ONR’s Superintending Inspector for Operating Reactors, said: “Since serving the notice we have worked closely with EDF and are satisfied that they have complied with the notice by addressing this safety shortfall.
“The work was completed before the return to service of the two reactors at Heysham 1.”
ONR issued the improvement notice to EDF under the Pressure Systems Safety Regulations 2000 (PSSR) Regulation 12 (Maintenance) and the Health and Safety at Work etc. Act 1974 Section 2(1).