Office for Nuclear Regulation

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LC11 Level 1 Emergency Exercise ‘Pluto’ (‘Beyond Design Basis’) and Annual Review of Safety and Security

Executive summary

Purpose of Intervention

The purposes of this week of interventions at EDF Energy Nuclear Generation Ltd’s (NGL) Torness power station were to:

The interventions were planned as part of ONR’s inspection strategy for operating reactors and the inspection plan for Torness.

Interventions Carried Out by ONR

I carried out this intervention in my capacity as nominated site inspector for Torness Power Station.

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

I observed Level 1 emergency exercise ‘Pluto’ with a team of ONR inspectors including the Head of Operating Reactors, the security inspector for the station, and three other safety inspectors.

The ARoS is an event where station management meet safety, security and environmental regulators (ONR and SEPA) to present a self-critical analysis of the performance of the site over the past twelve months and the priorities for further improvement. This included a walk-down of the plant, a series of presentations and an opportunity for the regulators to respond.

I also had routine meetings with a number key staff at the power station to exchange information.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

Exercise Pluto was designed to test the response to a severe (‘beyond design basis’) emergency, and the deployment of special equipment that is retained for such occasions offsite. As is normal, the shift team taking part were unaware in advance of the details of the exercise scenario, which in this case included multiple failures of power to the station and other simultaneous events. I judged that the scenario was suitably testing and that the station would have coped adequately with the emergency.

I found that the analysis presented in the ARoS was balanced and fair.

Conclusion of Intervention

Findings were discussed with station management. There are no findings from this inspection that could significantly undermine nuclear safety.  At present, no additional regulatory action is needed over and above the planned interventions at Torness.