Office for Nuclear Regulation

Sellafield – Inspection ID: 50538

Executive summary

Date(s) of inspection:

  • November 2022

Aim of inspection

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 this inspection was to sample evidence of implementation of the Sellafield Limited arrangements for compliance with LCs 10 (Training), 12 (Duly authorised and other suitably qualified and experienced persons), 24 (Operator instructions), and 26 (Control and supervision of operations), specifically within the High Level Waste Plant (HLWP) at the Sellafield site in West Cumbria, in order to inform a regulatory judgement regarding the licensee’s compliance with its legal duties under the nuclear site licence. The inspection allowed ONR to test the dutyholder’s progress with related open corporate regulatory issues (RI), as applicable.

Subject(s) of inspection

  • LC10 – Training – Rating – Green
  • LC12 – Duly authorised and other suitably qualified and experienced persons – Rating – Green
  • LC24 – Operating instructions  – Rating – Amber
  • LC26 – Control and supervision of operations – Rating – Green

Key Findings, Inspector’s Opinions and Reasons for Judgement Made

The inspection comprised discussions with Sellafield Limited staff and a review of the records and documents relevant to compliance with LCs 10, 12, 24 and 26.

For LC10, we identified no shortfalls requiring regulatory attention. We found evidence that, for the personnel sampled, the required training was found to be in date. We   noted the recent introduction of the electronic SQEP periodic review process and confirmed that the facility has achieved the target of less than 5% overdue.

For LC12, we identified no shortfalls requiring regulatory attention. We found evidence that SQEPs had been duly appointed, which were supported by appropriate records.

For LC24, we sampled some operating and maintenance instructions and found these to be suitable and we noted good progress with an ongoing review of these instructions. We also saw evidence of the appropriate use of operator instructions, and the identification and amendment of errors using the ‘red pen’ process, during tasks such as a plant walkdown. However, we identified multiple examples of instructions with steps important to safety not being completed including sign off by the DAP or others as appropriate. Whilst we are satisfied that there is no immediate safety risk to plant personnel or the public, HLWP is not fully compliant with the licensee’s corporate arrangements for LC24. We consider this to represent a significant shortfall against relevant good practice which we intend to consider within the framework of ONR’s Enforcement Management Model in order to determine the appropriate level of enforcement action to be taken.

For LC26, we identified no shortfalls requiring immediate regulatory attention. We found that SQEP personnel had been appointed and were effectively controlling and supervising operations. We sampled several Conservative Decision Making (CDM) and Operational Decision Making (ODM) records and were satisfied that, in the main, management appears to be following the required due process. We noted, however, that in some cases, the required wet signatures were absent and that there was no evidence of ‘electronic’ signatures. It was further observed that the timing and recording of periodic reviews was variable. The requirement for improvements to management of ODMs and CDMs was raised as an observation at the previous inspection in March 2022. Only limited progress appears to have been made in this area since then and we therefore consider it proportionate to raise a Level 4 (i.e., the lowest level) regulatory issue to ensure the licensee makes the required improvements here.


On the basis of evidence sampled during the inspection, the inspection team judged that Sellafield Limited is compliant with the requirements of LCs 10, 12 and 26 at HLWP. We assigned an inspection rating of Green in respect of these LCs. We judged that Sellafield Limited is not compliant of the requirements of LC 24 at HLWP. We assigned an inspection rating of Amber in respect of LC24.