An investigation has found a steam leak at Heysham 1 nuclear power station could have seriously injured staff.
The incident at Heysham was caused when a valve controlling steam from the reactor failed.
A report by the Office for Nuclear Regulation (ONR) found the valve system had not been maintained.
Now, the ONR has served an improvement notice on EDF Energy Nuclear Generation Ltd (EDF Energy) following the incident.
The incident occurred on December 23 last year 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.
However, ONR identified the potential for serious personal injury, if people had been present in the area near the valve.
Mike Webb, ONR’s Superintending Inspector for Operating Reactors, said: “Our investigation found that EDF had failed to ensure that the valve system was properly maintained and, by failing to do this, EDF had put at risk the safety of their employees.
“We will engage with EDF during the period of the improvement notice to ensure positive progress is made to address the shortfall.”
ONR has 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).
EDF has until 30 April to comply with the improvement notice.
In a statement, a spokesperson for EDF Energy said: ‘’We accept the ONR's findings and are working hard to ensure these are addressed.
We are also carrying out a full review to understand how this issue occurred and will share the outcomes and findings with the ONR.’’


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