Executive summary
Date(s) of inspection:
March 2024
Aim of inspection
ONR conducted an inspection at Trillium Flow Technologies (Trillium) in Alloa, Scotland to support the regulation of the Hinkley Point C (HPC) supply chain.
The inspection covered manufacturing and testing activities for the essential service water system (SEC) pump. The SEC pump was selected for inspection by ONR based on its importance to nuclear safety and taking account of operational experience from other EPR plant.
The aim of the inspection was to gain confidence in the implementation of the NNB Generation Company (HPC) Limited’s (NNB GenCo) arrangements for oversight of manufacturing activities and that the components delivered to site will be fit for purpose in terms of fulfilling safety case requirements.
The inspection included discussion with the licensee NNB GenCo, Trillium’s managers and workers, observation of testing, workshop and machine shop activities and a sample review of documentation. As part of this, the inspection considered relevant implementation of Licence Conditions (LC) 17 and 19 by NNB GenCo to gain confidence in:
- the project’s oversight of the manufacturing of the SEC pump by Trillium, including activities undertaken by sub-suppliers;
- the components delivered to site will be fit for purpose in terms of fulfilling the safety case requirements;
- management of factory acceptance testing, including licensee oversight; and
- the adequacy of NNB GenCo’s gate controls for shipping to site.
Subject(s) of inspection
- LC17 - Management systems - Rating: GREEN
- LC19 - Construction or installation of new plant - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
Prior to the inspection NNB GenCo provided ONR with a SEC pump technical briefing. This informed ONR on the safety functions, relevant operational experience (OPEX) and the role that Trillium has in the procurement of the SEC pump and any concerns. Based on a review of the information provided by NNB GenCo prior to the inspection, ONR did not identify any significant shortfalls in the licensee’s arrangements for compliance with LC 17 and LC 19.
During the inspection ONR considered the following evidence to judge the adequacy of NNB GenCo’s oversight arrangements:
- findings from a comprehensive walkdown of the service centre;
- a sample review of documentation;
- discussion with the NNB GenCo staff and Trillium managers and workers; and
- technical presentations from the NNB GenCo and Trillium.
Based on the evidence sampled we concluded that:
- NNB GenCo is providing adequate oversight of the manufacturing activities carried out by its supplier;
- we gained sufficient confidence that the pumps manufactured by the supplier will be fit-for-purpose in terms of fulfilling safety case requirements;
- there was an adequate cascade of culture and learning from the licensee into its supply chain for the components sampled; and
- NNB GenCo is maintaining sufficient oversight of factory acceptance testing for the SEC pump.
Conclusion
On the basis of the intervention evidence sampled relation to LC 17 and LC 19, ONR judged that NNB GenCo has adequate arrangements in place. ONR considers relevant good practice to be generally met in comparison to the appropriate benchmarks. Therefore, ONR has assigned an inspection rating of GREEN.