NSSS 18 - LC 19 Management of NSSS non-conformances

• Site: Hinkley Point C
• IR number: 20-013
• Date: September 2020
• LC numbers: 19

Executive summary

Purpose of Intervention

This intervention was conducted remotely with staff from NNB Generation Company (HPC) Ltd (hereafter referred to as NNB GenCo) and Framatome's manufacturing facility at St Marcel France. It was undertaken as part of the ONR intervention plan, HPC Project Intervention Plan beyond J0.

Interventions Carried Out by ONR

I conducted a Licence Condition (LC) 19 (Construction or installation of new plant) compliance inspection targeted on the nuclear steam supply system (NSSS). This involved sampling evidence of NNB GenCo’s management of manufacturing non-conformances at Framatome St Marcel to inform judgements regarding the adequacy and effectiveness of NNB GenCo's oversight arrangements relating to the NSSS.

I assessed NNB GenCo’s LC arrangements against relevant good practice, which included ONR regulatory guidance.

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

NNB GenCo’s implementation of the CCIS tool to process non-conformances is a positive development and based upon the evidence observed during this intervention it is providing the required traceability of the relevant decisions and actions. The Framatome process for manufacturing non-conformances is well established and mature.  However, I have noted the following shortfalls:

The extant NNB GenCo procedures are obsolete as they refer to an organisational structure that no longer exists. While the revision of these procedures is recognised in the management of change procedure for the reorganisation of the quality function, these procedures have yet to be issued and are currently around nine months late. Since these procedures assign specific activities to roles that no longer exist there is a risk that treatment of manufacturing non-conformance reports (NCRs) may not have been performed adequately.

NNB GenCo’s procedure for manufacturing non-conformances requires that NNB GenCo performs a formal review of the list of highest quality class nuclear pressure equipment deviations with a view to escalate internal deviations to external if deemed necessary. While it appears that some review may be performed, it has not been performed routinely.

The non-conformances are assessed at the end of each year and used to inform the surveillance offer for the following year. However, it does not appear that NCRs are used in a structured manner to modulate the surveillance within the year. Consequently, opportunities to strengthen quality control in particularly weak areas may be missed.

Conclusion of Intervention

Overall, based upon the judgements described above, I have concluded that an inspection rating of ‘AMBER is appropriate for LC19 Construction or installation of new plant.

An appropriate regulatory issue will be raised to reflect the shortfalls identified during this intervention. The findings described above will also inform the progress of other related regulatory issues.