- Site: Heysham 2
- IR number: 21-159
- Date: February 2022
- LC numbers: 24
Executive summary
Purpose of Intervention
The main purpose of this intervention was to undertake a themed inspection related to extended loss of grid (ELOG) at EDF Energy Nuclear Generation Limited’s (NGL) Heysham 2 power station in line with the planned inspection programme contained in the Heysham 2 Integrated Intervention Strategy (IIS) for 2021/22.
The inspection was undertaken by a multi-disciplinary team of ONR inspectors, including the site inspector, fault studies and Probabilistic Safety Analysis (PSA) specialist inspectors.
The aim of the themed inspection was to review the updates made to the station operating procedures due to the ELOG safety case and the implementation of these changes against Licence Condition (LC) 24. NGLs overall response to ELOG is being tracked under level 2 issue 5547.
Interventions Carried Out by ONR
The inspection sampled the implementation of the licensee’s arrangements at Heysham 2 power station against LC24 (operating instructions). The objective of the inspection was to determine whether the licensee’s arrangements were adequately implemented and in accordance with the ELOG safety case requirements (Engineering Change 363183 version 3). The safety case is being assessed as part of NGLs response to RI 5547.
The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.
Explanation of Judgement if Safety System Not Judged to be Adequate
Not applicable – no system based inspections were completed during this intervention.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
The key findings of this inspection were that the implementation of the safety case was found to be adequate:
- The changes made within the engineering change (EC) had been adequately implemented in the technical specifications. Surveillance records and check sheets demonstrated that the technical specifications were adhered to during operations.
- The control room procedures had been updated to improve guidance to the operators during an ELOG fault and the control room operators were familiar with the changes to the procedures
- Training records for one of the operations shifts were confirmed to be up to date for ELOG training
- The ELOG ‘grab pack’ was present in the emergency control centre and emergency control staff were aware of the requirements of the safety case
- Plant walkdowns of the diesel generators, diesel transfer pumps and diesel bowser found no significant issues.
Conclusion of Intervention
Overall, based on the sample, we judge that the standard of compliance against the ELOG safety case requirements was consistent with relevant good practice and we are satisfied that the licensee is complying with its legal duties.
There are no findings from this inspection that could undermine nuclear safety at this time. At present, no additional regulatory action is needed over and above the planned interventions at Heysham 2 Power Station. It is our opinion that an inspection rating of Green (no formal action) is therefore appropriate for LC24.