Date(s) of inspection:
- February 2023
Aim of inspection
This inspection will consider the electrical isolation of reactor control rods at the Dungeness B (DNB) power station. This was a planned intervention and part of the 2022/2023 ONR integrated intervention strategy for operating reactors.
Subject(s) of inspection
- LC 22 – Modification or experiment on existing plant – Rating: Green
Key findings, inspector’s opinions and reasons for judgement made
The inspection activities undertaken at Dungeness B (DNB) focused on the implementation of the arrangements established for DNB de-fuelling aspirations and included the work activities undertaken to electrically isolate the reactor (R)21 and R22 control rods. The inspection considered the arrangements for electrical isolation of the R21 and R22 control rods in compliance with licence condition 22 and their implementation.
From the sample inspected:
- EDF Energy NGL adequately demonstrated the implementation of the arrangements established for the electrical isolation of the DNB R21 and R22 control rods, including inspection and observation of control rod isolations, a demonstration of the complete auditable trail of documentary evidence from a single isolation and positive confirmation that R21 control rods cannot be electrically withdrawn from the reactor, in accordance with licence condition 22.
On the basis of the evidence sampled at the time of the inspection, for the electrical isolation of reactor control rods inspection, I judge that EDF Energy NGL were able to adequately demonstrate the implementation of the arrangements in compliance with licence condition 22 at DNB. Noting ONR guidance on inspection ratings, it is my opinion that an inspection rating of GREEN – no formal action is merited here.
On the basis of this inspection and the evidnce sampled at the time of the inspection, I judge that the action named ‘ONR Arrange Intervention on Control Rods’ associated with regulatory issue RI-11114 can be closed.