Office for Nuclear Regulation

Hinkley Point C – Inspection ID: 51702

Executive summary

Date(s) of inspection:

  • April 2023

Aim of inspection

The purpose of this inspection was to assess the effectiveness of NNB Generation Company (HPC) Ltd’s (NNB GenCo’s) Licence Condition 7 improvement plan implementation in returning it to compliance. This improvement plan was created in response to the findings of an earlier ONR inspection, carried out in quarter 1 2022.

This inspection assessed the adequacy of organisational learning across the Hinkley Point C (HPC) site. It focused on the improvements made to the learning and improvement arrangements and on their implementation by the site centric teams, such as civils and mechanical, electrical and heating, ventilation and air-conditioning (HVAC) (MEH) installation. The inspection was performed in collaboration with NNB GenCo’s Independent Nuclear Regulation.

Subject(s) of inspection

  • LC7 – Incidents on the site – Rating: Green

Key findings, inspector’s opinions and reasons for judgement made

The deployment and use of the ‘Insight’ learning tool has significantly improved; arrangements are now up-to-date and available; investigation priority criteria are clear; investigation reports are consistent with existing templates; the investigation process is now strengthened by introduction of effectiveness reviews and sponsoring managers; and the management of competency and related number of competent and trained investigators keeps improving as well as the management of adverse trends.

There was evidence of effective learning between unit 1 and unit 2. There was also evidence of effective external learning. NNB GenCo revised its Corrective Action Review Group (CARG) terms of reference to our satisfaction. We observed a CARG meeting and concluded that NNB GenCo has made significant improvement in its effectiveness since February 2022.

Screening meetings and daily investigation screening meetings were found to be adequately managed. However, we found that the screening meeting process does not sufficiently support consideration of future nuclear safety impact of the incidents in a systematic way.

Overall, we consider NNB GenCo’s Licence Condition (LC) 7 improvement plan has been effective as it led to a significant evolution of NNB GenCo’s learning process.


This inspection was narrowly focused on improvements made to the site LC7 reporting and investigation arrangements, and has been rated GREEN, with only minor observations/areas for improvement identified. A regulatory issue has been raised to monitor resolution of the shortfall identified in NNB GenCo’s consideration of future nuclear safety aspects of its incidents in a systematic way.

We observed significant improvements in implementation of the site arrangements for compliance with LC7, including identification of a number of good practices. Self-evaluation by the NNB GenCo internal regulator demonstrated good alignment with observations and assessment by the ONR inspectors.