Office for Nuclear Regulation

Hinkley Point C – Inspection ID: 52467

Executive summary

Date(s) of inspection:

June 2023

Aim of inspection

The aim of this inspection was to gain assurance that the licensee’s arrangements for management and implementation of fabrication activities in the bunkers at Hinkley Point C (HPC) are adequate. This included sampling the internal arrangements of the licensee, its arrangements for controlling contractors on site and then sampling the implementation of those arrangements on site. Of specific interest were the operations and activities in bunkers where there has been repurposing of the area between materials types. A specific objective of this inspection was to gain assurance that a change from a carbon-steel to a stainless-steel fabrication environment was well understood and implemented in terms of understanding the risks involves and mitigating actions needed.

Subject(s) of inspection

  • LC 19 – Construction or installation of new plant – Rating: GREEN

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

This inspection centred around the repurposing of a bunker from the production of carbon steel liner sections for the main containment, to stainless steel pools, tanks, sumps and liners. This is an area where commercial changes have been made, the components involved have a significant nuclear safety function, the technical risk is high and a good understanding of the technical and cleanliness requirements of the different fabrication types is needed.

I performed an inspection into the arrangements for the control of contractors, cascading of requirements and execution of technical activities surrounding repurposing of facilities on site. I sampled the processes and procedures across the licensee, as well as those of the tier 1 contractor (Bylor). This included direct discussions with the licensee, with Bylor senior staff and with operatives recently re-trained as part of the repurposing project. For the sample taken, I have sufficient confidence that this project is being performed in a way that understands and controls the risks that the activities present.

I judge that processes, procedures and how they applied to the repurposing of the facilities sampled was adequate.


The arrangements for the repurposing of facilities between dissimilar materials and dissimilar components on the HPC site were, from the sample taken, adequate. The level of engagement and understanding from the licensee and contractor staff was good and the activities were well controlled. I judge that this inspection should be rated green (no formal action) against Licence Condition 19, construction or installation of new plant.