Skip to content

CD36 – IRWST Unit 1 Construction Assurance (Level 2)

  • Site: Hinkley Point C
  • IR number: 21-046
  • Date: February/March 2022
  • LC numbers: 19

Executive summary

Purpose of Intervention

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

This intervention was an inspection carried out to assess NNB GenCo’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.

Intervention Aim

The aim of this intervention was to assess the adequacy of NNB GenCo’s construction management arrangements, together with its application of relevant good engineering practice, in the installation of the stainless-steel liner to the inner containment refuelling water storage tank (IRWST). This intervention has arisen as a result of NNB GenCo’s notification to ONR that it was implementing a change to the originally conceived method of prefabrication and installation for the Unit 1 IRWST, and is a follow-on intervention to CD37, which focussed on design substantiation and installation readiness.

Explanation of Judgement if Safety System Not Judged to be Adequate

This section is not applicable as this was not a safety system inspection.

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

Responses to questioning were forthcoming, constructive, and provided confidence that the planned operations were being adequately managed with due consideration of the risks involved, at this stage of the installation process.

Overall, I was satisfied with the adequacy of NNB GenCo’s installation management and its application of relevant good engineering practice associated with the stainless-steel liner to the IRWST for Unit 1 at HPC.

Conclusion of Intervention

On the basis of the evidence sampled, and in recognition of progress to date, I was satisfied that arrangements in place comply with LC19. Accordingly, I assign an inspection rating of GREEN (No formal action) to this intervention. No regulatory issues were raised.