Office for Nuclear Regulation

Licence Condition Inspection of LC19, 21 and 22 – Secondary Shutdown System (SSD) Upgrade Project

Executive summary

Purpose of Intervention

The purpose of this inspection was to undertake compliance inspections at EDF Energy Nuclear Generation Limited’s Torness power station as part of the ONR Torness Integrated Inspection Strategy (IIS) for 2020/21.

Inspections Carried Out by ONR

License condition compliance inspections examine evidence to determine compliance against key license conditions (LCs). The license conditions assessed in this inspection were: LC 19 (Construction or Installation of New Plant), LC 21 (Commissioning) and LC 22 (Modification or Experiment on Existing Plant).

The Torness nominated site inspector, together with specialist mechanical, fault studies and external hazards inspectors conducted a license condition compliance inspection of the Nitrogen Secondary Shutdown System (SSD) Upgrade Project. The Project was ongoing at the time of the inspection, and some of the associated documentation was still to be progressed through the EDF approval process. ONR sampled the documents that were completed thus far. For brevity in this inspection report all ONR representatives are referred to as “I”.

The inspection comprised of discussions with the licensee staff, physical viewing and inspection of new and modified plant, and a desktop review of the licensee’s records and other associated safety submissions. The inspection was carried out remotely by the fault studies and external hazards specialist inspectors, with the site inspector and mechanical specialist carrying out the inspection on site.

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

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

From the areas targeted and the evidence I examined during the inspection, I consider the licensee has adequate arrangements for oversight and control of the Nitrogen Secondary Shutdown System Enhancement Project. I am satisfied the areas of the arrangements I sampled for LC 19, 21 and 22 are sufficiently robust. The ratings I have assigned for each of the Licence Conditions and any shortfalls are detailed below.

LC 19 (Construction or Installation of New Plant) I reviewed the appropriate safety submission and evidence of adequate documentation to justify the safety of the proposed construction. I examined quality records for new plant and conducted a plant walkdown of the new plant that had been constructed and installed.

I consider the licensee is undertaking the construction and installation of the new plant with adequate arrangements which have thus far been adequately implemented. The safety submission clearly identified the requirements for new plant with adequate substantiation and appropriate project stages were identified for construction and installation. I judged therefore, that a rating of Green (No formal action) was appropriate for License Condition 19.

LC 21 (Commissioning) I reviewed the compliance arrangements and evidence demonstrating implementation of the arrangements. I reviewed the Test and Commissioning Schedule and evidence that Suitably Qualified and Experienced Persons were appointed for the purpose of controlling, witnessing, recording and assessing the results of any commissioning activities. I examined the process for raising, tracking and resolving technical queries and concessions throughout the project phases.

I noted a minor shortfall in the appropriate sign off an Inspection and Test Plan. I consider this to be a minor shortfall to implement specific administrative requirements and provide adequate clarification on the associated processes. I therefore intend to raise a regulatory issue to resolve this shortfall.

Although I identified a minor shortfall, I was satisfied the arrangements and evidence of implementation were adequate in the other areas sampled. I consider the licensee demonstrated that appropriate controls and adequate arrangements are in place for commissioning the upgrades to the Secondary Shutdown System. I judged therefore, that a rating of Green (No formal action) was appropriate for License Condition 21.

LC 22 (Modification or Experiment on Existing Plant) – I reviewed the licensee’s relevant safety submission, control and compliance arrangements. I sampled the arrangements for modifying the existing nitrogen storage and distribution pipework, including details on substantiation and evidence that modifications are being effectively controlled. I reviewed the application of operational experience and learning for the modifications. I am content that the licensee has adequate arrangements for controlling the modification to the existing nitrogen secondary shutdown system, which have thus far been adequately implemented.

From the areas I sampled, there are adequate arrangements that are being adequately implemented to justify the safety of the proposed modifications. I judged therefore, that a rating of Green (No formal action) was appropriate for License Condition 22.

Conclusion of Inspection

Based on the evidence reviewed prior to and during the inspection, I am satisfied that the licensee’s arrangements for compliance with LC19, 21 and 22 are adequate for the Nitrogen Secondary Shutdown System Enhancement Project and are being adequately implemented. I judge that no formal regulatory action is required over and above the planned inspections at Torness.