Office for Nuclear Regulation

Sellafield – Inspection ID: 52725

Executive summary

Date(s) of inspection:

  • October 2023

Aim of inspection

In October 2021, a fall from height occurred within the low active cell in B205. During the investigation and subsequent prosecution, shortfalls were identified in relation to safe systems of work for cell entries; confined space working and permit to work procedures.

The purpose of this inspection is to seek assurance that Sellafield Limited’s arrangements for compliance against the Confined Space Regulations (CSR) 1997 are adequately implemented at Magnox Reprocessing Facility (MRF) and comply with the relevant expectations of ONR. In particular this inspection will focus on entry into confined spaces including cell entries.
This inspection is one of a number of planned confined space inspections which will inform ONR’s view of compliance across the Sellafield site.

Subject(s) of inspection

  • Confined Spaces – Rating: Green

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

This was a planned intervention to provide regulatory confidence in the management of nuclear site health and safety (NSHS) hazards associated with confined space working at Sellafield’s Magnox Reprocessing Facilities (MRF).

The intervention was conducted in-line with the planned inspection programme for Magnox Reprocessing.

This intervention forms part of a wider series of interventions regarding the management of confined space working across Sellafield. The interventions result from the findings of an accident within a confined space in October 2021 and to which Sellafield were subsequently prosecuted in March 2023.

This intervention was conducted by two ONR Nuclear Site Health & Safety Inspectors, the ONR site inspector and an observer on 12 and 13 September 2021. An agenda was prepared for the intervention and shared with Sellafield before the intervention.

The intervention comprised:

  • discussions with Sellafield staff;
  • site walk-down accompanied by Sellafield staff;
  • sampling of documents and records;

Regulatory advice and judgement were based on determining compliance with sections 2 and 3 of the Health and Safety at Work etc. Act 1974 and the relevant statutory provisions made under the Act ie The Confined Spaces Regulations 1997. ONR also consulted the relevant good practice such as:

  • Approved Code of Practice and guidance L101 Safe Work in Confined Spaces

For the intervention ratings we referred to the ONR General Intervention Guidance ONR-INSP-GD-064.

The inspection began with a discussion around how B268 personnel plan and undertake work within confined spaces. Topics discussed included:

  • B268’s management of confined spaces;
  • identification and planning of confined space work;
  • implementation of confined space work;
  • training requirements for confined space operatives;
  • emergency procedures; and
  • supervision and oversight of confined space operations.

The walkdown aspect of the inspection was limited to reviewing confined space entry into the thermal denitration (TDN) plant area within B268. No walkdown of B205 was undertaken during the inspection due to time constraints. No confined space working was observed during the inspection.

The risks associated with confined space working are well understood within the B268 and in particular associated with the TDN plant. Employees involved in confined space working (supervisors, management and doers) were well informed and the arrangements for managing the confined space entries were well developed.

Hundreds of entries into the confined space are made every year, ONR sampled safe system of work documentation from 2 of these entries. The documentation generally identified the specified risks well and associated control measures including roles, responsibilities and training requirements. ONR identified that whilst the risk assessment forms were not always completed fully, significant risks and control measures were sufficiently identified; this gap is more of an administrative one and Sellafield Limited should review the risk assessment forms for confined spaces to ensure usability.

Sellafield Limited’s confined space management arrangements are heavily dependent on two particular job roles – that of the Confined Space Supervisor (CSS) and that of the Safe System of Work Controller (SSC). Both are highly skilled roles requiring a high degree of knowledge, experience, control and management. Sellafield Limited should satisfy itself that it has sufficient skilled & experienced resource relevant to these roles across site where confined space entries are made.

Since there was not enough time or personnel available from Sellafield Limited Fire & Rescue Service (SFRS) to make a valid judgement on certain aspects of emergency arrangements these areas have not been rated. ONR will follow up these aspects with SFRS as part of the wider Confined Space Inspection Strategy.

Based on the evidence sampled during the inspection, I judged that there were no significant shortfalls against the Confined Space Regulations 1997 and associated relevant good practice. For this reason I have rated this inspection as green.


​​​​​​On the basis of the evidence sampled during the inspection, facility B268 has complied with the requirements of Regulation 3 (risk assessment) of the Management of Health & Safety at Work Regulations relating to work in confined spaces; and Regulation 4 (safe working in confined spaces) of the Confined Spaces Regulations 1997.

On the basis of the evidence of the limited sample of emergency arrangements for working in confined spaces, facility B268 appear to have complied with the requirements of Regulation 5 (emergency arrangements) of the Confined Spaces Regulations 1997. ONR inspectors will follow up emergency arrangements with SFRS and wider Sellafield Limited at a future intervention.

Management of Health and Safety at Work Regulations 1999, Regulation 3 – Risk Assessment. Rating green

Confined Spaces Regulations, Regulation 4 – Work in Confined Spaces. Rating green

Confined Spaces Regulations, Regulation 5 – Emergency Arrangements. Rating green

No Regulatory Issues raised