Office for Nuclear Regulation

Sizewell A Site – Inspection ID: 52765

Executive summary

Date(s) of inspection:

  • July 2023

Aim of inspection

The aim of the inspection is to undertake a regulatory compliance inspection against all duties imposed by the Fire Safety Order 2005, (Articles 8 to 22), or by regulations made under Article 24, to ensure that the licensee is compliant in respect of the premises: Specifically, to provide assurance that the Licensee’s arrangements associated with all applicable articles are suitable and adequate, and that the licensee is working to those arrangements.

Subject(s) of inspection

  • Fire (Life Safety) Compliance Inspection – Rating: Green

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

The inspection assessed Sizewell A’s arrangements to support Life Fire Safety (LFS) and sampled the implementation of those measures on site.  The inspection consisted of examination of the licensee’s and Principal Contactor (PC) Erith’s arrangements regarding LFS focusing on the Turbine Hall and Reactor Building – Boiler House areas where the PC are engaged in the removal of legacy scaffolding boards in an asbestos contaminated area. Meetings to assess the implementation and management of LFS and walkdowns of the focus areas were conducted. Supporting documentation in the form of the licensee’s and PC’s Fire Risk Assessments (FRA) and other supporting documentation were reviewed.

The areas inspected were targeted because of the potential for challenges to LFS due to the fire and life risk associated with the removal scaffolding boards, the complexity of the building, the requirement for coordination of fire safety management across multiple responsible persons and as a result of regulatory intelligence from similar inspections.

The intervention was rated Green for this topic, with a Level 4 Regulatory Issue (RI 11609) raised to address the minor issues raised.


This was a planned inspection at the Magnox Sizewell A site undertaken as part of the intervention strategy for the Decommissioning, Fuel and Waste (DFW) Sub-Division.

The inspection covered the fire safety arrangements, under the Regulatory Reform (Fire Safety) Order 2005, of both Magnox Sizewell A and it’s Principal Contractor Erith in the Turbine Hall and Reactor Building- Boiler House areas of site through walkdowns, discussion or assessment of documentation provided e.g., fire risk assessments.
Compliance was assessed using relevant ONR inspection guidance, specifically Technical Inspection Guide (TIG) NS-INSP-GD-073 Issue 2 – The Regulation of Life Fire Safety Provision on GB Nuclear Sites.

It was noted during inspection that PC’s fire risk assessment quantified escape travel distances against relevant good practice (RGP), in the form of the applied standard HSG 168 (Fire Safety in Construction), and that this process enables a clearer understanding of any potential risk gap that may exist between RGP and conditions encountered and thus enables clearer decisions to be made regarding any potentially required mitigations.

An adequate level of fire safety management was demonstrated in terms of general fire precautions, combustible fire load management and cooperation and coordination, between Magnox Sizewell A and the PC Erith.

I considered that the arrangements made under the Regulatory Reform (Fire Safety) Order 2005 were adequate. I judged the rating to be Green for this topic. I did however identify issues regarding the availability and suitability of escape routes and the management of authorisation for door wedges for which I require review of arrangements and the provision of further information. I have considered this, in line with ONR’s Enforcement Management Model, and have raised a Level 4 Regulatory Issue (RI 11609) requiring Magnox Limited’s (ML) Sizewell A to address the issues raised.