Office for Nuclear Regulation

LC19 inspection, CD12 - Readiness for Unit 1 Inner Containment Liner Cup Placement

Executive summary

Purpose of Intervention

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

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

This intervention is led by ONR civil engineering construction assurance (CECA) and seeks to assess the Licensee’s (i.e. NNBGenCo’s) application of relevant good practice in the area of construction planning for the placement of the steel inner containment liner of Unit 1 upon the Unit 1 common raft (referred to as CRX).

Intervention Aims

ONR wishes to gain oversight of the licensee’s construction planning activities for the following purposes:

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

The intervention was well managed and NNB planned for attendance by the appropriate personnel. Responses to questioning were forthcoming, informative and provided me with confidence that the planned operation was being adequately managed, with due consideration of the risks involved.

Overall, I was satisfied that the licensee’s current arrangements will ensure that all relevant surveys and inspections will be in place prior to the planned lifting operation.

I was satisfied that the licensee’s arrangements for controlling the contractor’s planning activities were adequate.

There was an observed omission from the works specification pertaining to one aspect of the permissible gap beneath the cup once installed. Given the status of the works, I was satisfied with the licensee’s proposal to address this point in a manner that will ensure that the compliance of the works with the design intent will be assured. Furthermore, I am satisfied that the risk of non-conformance of the works with the design intent is being adequately managed for this specific aspect.

Conclusion of Intervention

On the basis of the evidence sampled, I was satisfied that the proposed arrangements met relevant good practice.

I judge that an inspection rating of GREEN (No formal action) is appropriate for Licence Condition 19 in respect of the planned cup lift for the Unit 1 inner containment.