Date(s) of inspection:
- February 2023
Aim of inspection
The aim of the system based intervention (SBI) is to establish whether the EDF Energy Nuclear Generation Ltd (EDF NGL) Heysham 1 (HY1) power station reactor safety circuits (RSCs) are able to fulfil their safety duties (safety functional requirements) in line with the safety case (the HY1 Living Safety Case Document (LSD) – System Based View (SBV) – Part 3.17.01 – Primary (Main) Guardline System). This will be achieved through a sample based inspection of associated arrangements, a plant walkdown, and discussions with various stakeholders, (e.g. operators, maintainers, engineers, and training administrators).
This SBI will be undertaken as part of the HY1 integrated intervention strategy (IIS) plan.
Subject(s) of inspection
- LC10 – Training – Rating: Green
- LC23 – Operating rules – Rating: Green
- LC24 – Operating instructions – Rating: Green
- LC27 – Safety mechanisms, devices and circuits – Rating: Green
- LC28 – Examination, inspection, maintenance and testing – Rating: Green
- LC34 – Leakage and escape of radioactive material and radioactive waste – Not rated
- Overall Inspection Rating: Green
Key findings, inspector’s opinions and reasons for judgement made
The key findings of our system based inspection (SBI) of the Heysham 1 (HY1) reactor safety circuits (RSCs) are:
LC 10 – Training: We examined the training records of a number of personnel involved with the oversight, maintenance, and operation of the RSCs and judged that they were suitably qualified and experienced personnel (SQEP). We also reviewed RSC training material and found its scope and contents to be appropriate. We therefore assigned an integrated intervention strategy (IIS) rating of Green (no formal action) for LC 10.
LC 23 – Operating rules: We reviewed technical specification (tech spec) 4.2.1 (reactor safety circuit settings) and the associated commentary (C4.2.1) and discussed their application with operators. As a result, we judged that the tech spec and commentary were clear and straightforward to follow. We also confirmed that the associated surveillance requirements (SRs) were being undertaken as required. A couple of shortfalls in the associated paperwork were identified; however, we do not consider that these present an immediate risk to nuclear safety and will track their progress to resolution as part of normal regulatory business. We therefore judged that compliance was being achieved with the RSC operating rules specified in the safety case. We therefore assigned an IIS rating of Green (no formal action) for LC 23.
LC 24 – Operating instructions: We examined the main station operating instructions (SOIs) associated with the RSCs and discussed their application with operators. As a result, we judged that adequate operating instructions were in place to support RSC operations. We therefore assigned an IIS rating of Green (no formal action) for LC 24.
LC 27 – SMDCs: During the SBI we reviewed several engineering, operating, and maintenance documents, undertook a plant walkdown and spoke to a number of stakeholders. As a result, we judged that the RSCs were connected correctly, were in working order, and were being adequately maintained. We also judged RSC configuration was being adequately controlled and that adequate numbers of spares were available. We therefore assigned an IIS rating of Green (no formal action) for LC 27.
LC 28 – EIMT: We reviewed a number of RSC maintenance work instructions (WIs), and associated work order cards (WOCs) and checksheets. As a result, we considered that the associated maintenance tasks had been adequately defined and had been carried out as specified. We also found that each of the sampled maintenance tasks had been completed in line with the periodicity specified in the maintenance schedule. We therefore judged that the RSCs were being adequately examined, inspected, maintained, and tested. We therefore assigned a IIS rating of Green (no formal action) for LC 28.
SBI 27 Conclusions
From the evidence sampled during this SBI against LC 10, 23, 24, 27 and 28, we judged that the RSCs were able to fulfil their safety duties (safety functional requirements) in line with the safety case.
There are no findings from this intervention that could significantly undermine nuclear safety at HY1. At present, no additional regulatory action is needed over and above the planned interventions at HY1, as set out in the HY1 IIS, which will continue as planned.
We therefore judged the overall IIS rating for the SBI to be Green (No formal action).