Executive summary
Date(s) of inspection: March 2024
Aim of inspection
ONR conducted an inspection at Sempell GmbH in Korschenbroich, Germany as part of the regulation of Hinkley Point C's (HPC) supply chain. The inspection sample covered manufacturing and testing activities for the pressuriser safety relief valve (PSRV). ONR selected the PSRV because of its importance to nuclear safety and taking account of operational experience from other EPR plant.
The aim of the inspection was to seek evidence that the implementation of NNB Generation Company (HPC) Limited's (NNB GenCo) arrangements for oversight of manufacturing activities is adequate 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, and representatives from Sempell and Framatome. ONR observed representative valve manufacturing and carried out a sample review of PSRV documentation. This inspection considered NNB GenCo’s implementation of its Licence Condition (LC) 17 and 19 arrangements to gain confidence in:
The aim of the inspection was to seek evidence that the implementation of NNB Generation Company (HPC) Limited's (NNB GenCo) arrangements for oversight of manufacturing activities is adequate 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, and representatives from Sempell and Framatome. ONR observed representative valve manufacturing and carried out a sample review of PSRV documentation. This inspection considered NNB GenCo’s implementation of its Licence Condition (LC) 17 and 19 arrangements to gain confidence in:
- the project’s oversight of the manufacturing of the pressuriser safety relief valves by Sempell, 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
In advance of the inspection NNB GenCo provided ONR with a PSRV technical briefing. This informed ONR on the safety functions, relevant operational experience (OPEX) and the role that Sempell has in the procurement of the essential service water system (SEC) pump and any concerns. ONR undertook a review of the information provided by NNB GenCo prior to the inspection and did not identify any significant shortfalls in the licensee’s formal 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:
During the inspection ONR considered the following evidence to judge the adequacy of NNB GenCo's oversight arrangements:
- observations from a comprehensive walkdown of Sempell’s service centre;
- a sample review of Sempell’s documentation;
- discussion with the NNB GenCo staff and Sempell’s representatives; and
- technical presentations from NNB GenCo, Framatome and Sempell.
Based on the evidence sampled we concluded that:
- NNB GenCo is providing adequate oversight of the manufacturing activities carried out by Sempell and the associated sub tier supplier;
- based on the confidence we gained, the PSRV supplied by Sempell 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;
- there was clear evidence of Sempell having a positive nuclear safety culture which appeared to be embedded within the organisation; and
- NNB GenCo is maintaining sufficient oversight of factory acceptance testing for the PSRV.
Conclusion
Based on ONR observations during the walkdown and office based discussions, ONR considered Sempell to be a capable supplier.
On the basis of the inspection evidence sampled in relation to LC 17 and LC 19, ONR judged that NNB GenCo has adequate arrangements in place and relevant good practice to be generally met in comparison to the appropriate benchmarks. Therefore, ONR has assigned an inspection rating of GREEN (no formal action).
On the basis of the inspection evidence sampled in relation to LC 17 and LC 19, ONR judged that NNB GenCo has adequate arrangements in place and relevant good practice to be generally met in comparison to the appropriate benchmarks. Therefore, ONR has assigned an inspection rating of GREEN (no formal action).