Date(s) of inspection:
- April 2023
Aim of inspection
The aim of these interventions at EDF Energy Nuclear Generation Ltd’s (NGL) Torness power station are to observe a ‘Level 1’ emergency exercise to ensure Licence Condition (LC)11 arrangements are adequately implemented.
The EDF NGL Torness’s Annual Review of Safety, Security and Environment (ARoS) will also be attended where Torness present a self-critical analysis of the performance of the site over the past twelve months and the priorities for further improvement.
Subject(s) of inspection
- LC11 – Emergency arrangements – Rating: GREEN
Key findings, inspector’s opinions and reasons for judgement made
The purpose of this week’s interventions at EDF Energy Nuclear Generation Ltd’s (NGL) Torness power station was to:
- Observe ‘Level 1’ emergency exercise ‘LYRA’ the purpose of which was to demonstrate that arrangements for emergency response, required by Licence Condition (LC) 11 are adequately implemented
- Attend and participate in EDF NGL Torness’s Annual Review of Environment, Safety and Security (ARoS)
The interventions were planned as part of ONR’s inspection strategy for operating reactors and the 2023/24 inspection plan for Torness.I carried out these intervention in my capacity as nominated site inspector for Torness Power Station. My inspections were informed by ONR technical guidance.
I observed the Level 1 emergency exercise ‘LYRA’ with a team of ONR inspectors including the Head of Operating Reactors, 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 plant walk down, and a series of presentations where regulators have the opportunity to ask questions and respond to the material presented.
Exercise “Lyra” was a safety related exercise and was designed to test the response of site to an abnormal plant condition initiated by incorrect plant being worked on, leading to increased radiological conditions coincidental with a major valve failure and involved four casualties being identified. There were also security aspects to consider, mainly around a normally secured door being open and the arrival of media at the station main gate, requesting permission to deploy a drone. The incident resulted in an “off site nuclear event” and full site muster.
As is normal, the shift team taking part was unaware in advance of the details of the exercise scenario.
I judged that the scenario was suitably testing, I observed significant improvement from previous demonstrations including casualty handling and extraction, clear focus and action board management in the command centres, integration of external emergency services and consideration of security risks.
However, there was one identified shortfall in station meeting one of their objectives set out for this Level 1 emergency exercise. This objective was associated with achieving Reactor 1 blowdown to ensure public protection. This is achieved through a filtered blowdown route which requires use of instructions and manual intervention to reconfigure valves.
There was some confusion on whether a filtered blowdown had been achieved. The control room believed a filtered blowdown had been carried out, however it was observed that a valve between the bypass gas plant and reactor 1 was not in the correct configuration to achieve this.
Torness informed ONR that they would investigate this shortfall and identify improvement actions to prevent a recurrence. ONR will monitor the output from the investigation through a regulatory issue and will observe a future shift exercise to ensure improvements have been adequately implemented.
I considered the Torness ARoS to be well attended, the plant walk down was very informative and covered a wide range of improvements which had been undertaken to improve safety and reliability. Stations presentation and analysis of the past year was balanced and fair, acknowledging the challenges ahead to maintain safe and secure operations.
Level 1 exercise “LYRA”
Station’s own feedback self-identified most of the key findings following the level 1 exercise demonstration. ONR acknowledged that there have been real improvements observed compared to previous exercises in the areas of casualty handling/extraction, sense of urgency, board management and consideration security implications. There are no findings from this inspection that could significantly undermine nuclear safety and an adequate demonstration of the Torness emergency arrangements was observed. ONR will monitor stations output form the investigation to further improve exercise performance through a level 4 regulatory issue and will observe a future control room simulator shift exercise to ensure improvements have been adequately implemented. The Torness site inspector will write to the station summarising ONR’s observation findings and any forward actions required.
I considered the Torness ARoSS to be well attended, the plant walk down was very informative and covered a wide range of improvements which had been undertaken to improve system safety and reliability. Stations presentation and analysis of the past year was balanced and fair, acknowledging the challenges ahead to maintain safe and secure operations. The Torness ARoSS presentation is attached to this IR in the document section.