Office for Nuclear Regulation

Sellafield – Inspection ID: 22-016

  • Site: Sellafield
  • IR number: 22-016
  • Date: May 2022
  • LC numbers: 22

Executive summary

Purpose of Intervention

The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with the Sellafield site licensee (Sellafield Ltd) against a strategy defined by the ONR Sellafield, Decommissioning, Fuel and Waste (SDFW) Division. The planned inspection schedule for 2022/23 identifies the Licence Conditions (LCs) and regulations that will be inspected during this period.

The purpose of this intervention was for ONR to determine the adequacy of implementation of Sellafield Ltd’s arrangements for compliance with LC22 ‘Modification or experiment on existing plant” at the Thermal Oxide Reprocessing Plant (THORP).

The overall adequacy of Sellafield Ltd’s site-wide arrangements for LC22 is considered separately in other ONR interventions.

Interventions Carried Out by ONR

I, the Site Inspector for THORP and Spent Fuel Services undertook an inspection against compliance with LC22 ‘Modification or experiment on existing plant’.

I also undertook a walk down of the Advanced Gas Reactor Fuel Route with the Sellafield Compliance Intelligence and Enforcement Delivery Lead Superintending Inspector and a Nuclear Liabilities Regulation Specialist Inspector, and a review of regulatory issues with the Spent Fuel Services Operating Unit.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable since these were not safety system-based inspections.

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

I found that THORP is mostly compliant with the site’s LC22 arrangements, with some minor shortfalls identified. THORP’s Engineering Manager has a good overview of the modifications on or planned for the plant and was able to demonstrate control of plant in relation to LC22.

THORP has driven down overdue plant modification proposals (PMPs) to zero and is now focussed on reducing overdue temporary plant interventions (TPIs), temporary software modifications (TSMs) and software modification requests (SMRs). The status of modifications presented to me was accurate and this was evidenced by the walk down of the THORP Central Control Room and the sampling of logs there, and then comparing it to the central logs.

There were also some minor observations from the sampled PMPs, and I am satisfied that THORP has already started to action these. Regulatory advice was also provided in relation to the non-compliances identified.

Conclusion of Intervention

Based upon the evidence sampled for the implementation of the LC22 ‘Modification or experiment on existing plant’ arrangements at THORP, an inspection rating of Green is considered appropriate. No regulatory issues have been raised.