Office for Nuclear Regulation

Sellafield – Inspection ID: 50532

  • Site: Sellafield
  • Inspection ID: 50532
  • Date: September 2022
  • LC numbers: 35, 36

Executive summary

Purpose of intervention

In accordance with the Office for Nuclear Regulation’s (ONR) Sellafield Strategy, each year ONR performs a series of planned inspections to seek assurance of compliance of selected licence conditions (LC), targeted at those facilities with significant importance to nuclear safety.

The aim of the inspection was to confirm compliance with LCs 35 (Decommissioning) and 36 (Organisational capability) within the Highly Active Liquor Evaporation and Storage (HALES) facility and the High Level Waste Plants (HLWP) that make up the Highly Active Liquor (HAL) Programme within the Sellafield Ltd Spent Fuel Management (SFM) value stream.

The inspection was focussed on the ongoing and future activities in the facilities in support of post-operational clean out (POCO) with some coverage of future decommissioning. This included:

  • the plans, timescales, and justification (e.g. in respect of ongoing LC compliance, ALARP etc.) of these activities;
  • the control and governance of these plans, and the engagement between facilities within and beyond the HAL Programme and at the corporate level;
  • the human resources, capability and organisation structure needed to support the work.

This inspection was conducted jointly with the Environment Agency and with the involvement of the Sellafield Ltd internal regulator: Nuclear Independent Oversight (NIO).

Subject(s) of inspection

  • LC35 – Decommissioning (Rating – Green)
  • LC36 – Organisational capability (Rating – Green)

Key findings

The inspection comprised discussions with Sellafield Limited staff and a review of the records and documents relevant to compliance with LCs 35 and 36.

For LC35 (Decommissioning) we noted that HALES was three years from entering POCO (due in 2025) and that the Waste Vitrification Plant (WVP) was not due to enter POCO until 2030.We reviewed the POCO plans and decommissioning mandates, POCO leadership and governance, and on the current approach to the managing medium and high activity wastes that will arise as a result of POCO and the eventual decommissioning of the facilities.We were content that HALES and WVP are planning and preparing for POCO in line with the Sellafield arrangements which apply to their stage in the facility lifecycle. We noted the risks to developing a POCO delivery schedule if an expected end state cannot be defined and gave Sellafield regulatory advice on this matter.

For LC36 (Organisational capability) we discussed the maintenance and management of the nuclear baseline, sampled the application of organisation change management processes and inspected the implementation of the minimum safe manning level (MSML) arrangements, including confirming that the MSML was satisfied on the day of the inspection with the exception of a mitigated shortfall (in line with Sellafield Ltd processes) relating to one post at WVP.

Some regulatory advice was provided and we recognised theenterprise-wide challenges that the licensee is facing in respect of its wider organisational capability.


On the basis of evidence sampled during the inspection, the inspection team judged that Sellafield Limited is compliant with the requirements of LCs 35 and 36 in the HAL Programme facilities: HALES and HLWP. We assigned an inspection rating of GREEN in respect of both LCs for both facilities.