Executive summary
Date(s) of inspection:
- October 2025
Aim of inspection
The aim of the inspection is to assess application of NNB Generation Company (HPC) Ltd's (NNB GenCo) Licence Condition (LC) 17 and LC19 arrangements for controlling the release of the Hinkley Point C (HPC) unit 2 reactor pressure vessel (RPV). ONR intervention IIS-51676 considered NNB GenCo's arrangements with the release of the Unit 1 RPV, and subsequently undertook IIS-51686 to understand the preparations of the End of Manufacturing Record (EoMR) for the unit 1 steam generator SG#428 before its “ex-works”, both from Framatome. With that backdrop and applying ONR's Risk Informed Targeted Engagements (RITE) policy, this is a follow-on activity to understand what lessons have been learnt since and how the identified improvements have been implemented in the activities demonstrating readiness for the U2 RPV “ex-works”, whilst recognising that there are no associated ONR permissioning activities.
Subject(s) of inspection
- LC 19 - Construction or installation of new plant - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
The reactor pressure vessel RPV is identified by the Licensee, NNB GenCo Limited at Hinkley Point C (HPC), as a high integrity component (HIC) whose failure could lead to large unmitigated consequences. Therefore, in addition to compliance with the HPC design referential RCC-M requirements there are additional requirements to be met to demonstrate HIC compliance. To minimise the nuclear safety risks post shipment of HPC Unit 2 RPV from the manufacturer’s premises, known as ‘ex-works’, evidence demonstrating compliance to the design code and HIC requirements are needed.
Considering that the U2 RPV has several constituting parts and that for each part the evidence pack is significantly detailed and voluminous due to the compliance requirements as discussed above, I judged that targeting one of the eight representative outlet/inlet nozzles including the safe ends (S/E) for sampling purposes would be proportionate.
I have examined how the licensee has managed the Gateway Passport process for the “ex-works” of the U2 RPV along with the supporting evidence, which included the implemented improvements, the activities undertaken by several contributory stakeholders at different steps of the process, the leadership demonstrated by the licensee in controlling the process and collaboratively arriving at the final decision that the component is fit for release to site.
Conclusion
Based on the evidence sampled I am content that:
- the improvements have been made to the process from the previous samplings and the licensee has demonstrated continuous improvement
- I have managed to establish the golden thread in the supporting evidence for manufacturing and testing including the traceability of parts
- there is adequate evidence of surveillance activities undertaken by the licensee and various stakeholders as warranted by the process
- the compilation of the end of manufacturing record (EoMR) for the sampled inlet/outlet nozzles including the safe ends is satisfactory
- there is robust evidence of ITPIA activities and demonstration of compliance with the NPE policy requirements for the sampled part
- the summary evidence document for the U2 RPV provides sufficient demonstration of compliance with evidence against the relevant nuclear safety claims
- there is sufficient evidence to demonstrate the sentencing for the “ex-works” of the U2 RPV via the licensee's Gateway Passport process
I have judged that the licensee, NNB Generation Company Ltd's (NNB GenCo) has demonstrated compliance with Licence Condition (LC) 17 and LC19 arrangements for controlling the release of the Hinkley Point C (HPC) unit 2 reactor pressure vessel (RPV). I have therefore concluded to assign the GREEN rating for the intervention.