Office for Nuclear Regulation

Heysham 2 - LC28 inspection - Graphite Core

Executive summary

Purpose of Intervention

The intervention took place at Heysham B (HYB) on 12th February 2020 during its periodic reactor 8 shutdown as part of the licensee’s, EDF Energy Nuclear Generation Limited’s (NGL), compliance with Licence Condition (LC) 30.  The purpose of the intervention was to inspect the adequacy of the licensee’s examinations and inspections of the graphite core and determine compliance with LC 28(1).

Purpose of Intervention

In relation to the graphite core I carried out the following inspections in order to determine compliance with LC 28:  Examination, inspection, maintenance and testing.

Interventions Carried Out by ONR

For this intervention, I was accompanied by another graphite specialist inspector and I have met with NGL personnel in charge of the graphite core inspections. During this intervention, I performed the following tasks:

Explanation of Judgement if Safety System Not Judged to be Adequate


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

At the time of the site intervention, the graphite inspections had only just started. NGL had completed the inspections of 2 of the 16 channels, with no reported defects. However, this was consistent with the planning of the inspections. There was no apparent issue which could prevent the scope of the graphite inspections from being completed.

According to the documentation that I sampled during the intervention, the licensee appeared to comply with the Quality Assurance requirements. The quality of the video footage I observed appeared to be of sufficient quality to allow for appropriate detection and sentencing of any defects that could be observed. The training records I sampled were up-to-date and relevant to the tasks carried out by the operators. The station staff I spoke to during the intervention appeared to be knowledgeable and suitably experienced. The graphite core inspection that I observed during my intervention appeared to have been carried out with appropriate rigour.

In my view, the licensee’s arrangements for the graphite core inspections appeared to be appropriate. I did not observe any shortfall in these arrangements.

Conclusion of Intervention

Overall, from the activities I sampled during my intervention, I found that the licensee, EDF Energy Nuclear Generation Limited, was complying with LC 28 with respect to the graphite core inspections. I consider that an inspection rating of ‘Green’ is warranted.

A forthcoming assessment report will consider whether the results from the examinations and inspections are consistent with the graphite safety case in order to support ONR’s return to service consent activities.

A separate site intervention is planned on 26th February to determine the adequacy of the graphite peripheral brick inspections.