Office for Nuclear Regulation

Hinkley Point C - Planned compliance inspection - LC19

Executive summary

Purpose of Intervention

In accordance with the Office for Nuclear Regulation (ONR) Hinkley Point C Construction Intervention Plan, ONR performs a series of planned compliance inspections of identified licence conditions. This is to ensure that the licensee, NNB Generation Company (HPC) Ltd (NNB GenCo), is adequately developing and implementing its licence condition compliance arrangements in a manner commensurate with the stage of the project under consideration.

The purpose of this intervention was to assess the improvements made by NNB GenCo in response to its internal Quality in Engineering supporting Construction (QiC) inspection, supporting report and subsequent improvement plan.

Interventions Carried Out by ONR

This intervention was carried out to assess the licensee’s compliance with licence condition 19 (LC19) Construction or Installation of New Plant. LC19 requires that where the licensee proposes to construct or install any new plant, which may affect safety, the licensee makes and implements adequate arrangements to control the construction or installation.

ONR carried out a remote intervention over two days with two ONR inspectors. The objectives of which can be summarised as follows:

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

The engagement with NNB GenCo on the QiC topic and this intervention has been informed primarily though the NNB GenCo Independent Technical Assessment (ITA) team. ONR commended the quality of the investigations, and the three associated reports, led by the ITA team.

NNB GenCo appears to have improved control of design delivery and the revised arrangements within the supporting organisations appear to be having a positive impact on design quality. Communication between design, management and construction stakeholders appears to have improved substantially.

Delivery oversight managed by the NNB GenCo Plant Integration team appeared positive and metrics were being proactively used to make decisions to manage the project schedule.

ONR recognised the importance of the design assurance barrier review which was undertaken by NNB GenCo. Whilst most of the emphasis was placed on improving the Responsible Designer assurance barriers, ONR acknowledged increased NNB GenCo surveillance on design work packages, using the Design Engineering Team to perform model surveillance.

The totality of the QiC improvement measures appears to have resulted in a reduced number of significant design Non-Conformance Reports over the last 12 months. However, this metric needs to be viewed with caution given the small sample size and it would be naïve to use this as a single source to assess the success of improvements. 

The relatively new Post-Handover Open Point arrangements appear robust and can be used to address a wide range of emergent design issues. ONR noted that historically it appears that design issues identified once the design package had been released to site were managed through ad-hoc instructions via the NNB GenCo project manager. Whilst this achieved a suitable outcome, the decision making process was unclear.  All NNB GenCo staff questioned separately during the intervention had a consistent understanding of the Post-Handover Open Point principals which suggested NNB GenCo’s internal systems supported the new arrangements.

There was one remaining open point on the QiC action plan, which related to implementing learning outside civil engineering. ONR was satisfied in how this is to be closed.

Conclusion of Intervention

Given NNB GenCo’s progress in implementing the activities in the QiC improvement plan and the evidence gathered during this intervention relating to improvements in the delivery and quality of the design, action 2 of Regulatory Issue #7445, NNB GenCo to demonstrate adequate progress against the improvement plan to resolve the overarching issue, can be closed.

On the basis of the evidence gathered during this inspection, I judge that an inspection rating of GREEN, with no formal action, is appropriate against Licence Condition 19.