Office for Nuclear Regulation

Sellafield – Inspection ID: 50658

Executive summary

Date(s) of inspection:

  • January 2023

Aim of inspection

The purpose of the inspection was for ONR to examine whether the licensee’s safety case claims in respect of Civil Assets and Bridges under the control of the Utilities organisation had been adequately implemented.

Subject(s) of inspection

  • LC10 – Training – Rating: Green
  • LC23 – Operating rules – Rating: Green
  • LC24 – Operating instructions – Rating: Amber
  • LC27 – Safety mechanisms, devices and circuits – Not rated
  • LC28 – Examination, inspection, maintenance and testing – Rating: Green
  • LC34 – Leakage and escape of radioactive material and radioactive waste – Not rated

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

ONR’s System Based Inspection (SBI) process examines evidence to determine compliance against six licence conditions (LC). These LC’s, listed below, have been selected in view of their relevance to ensuring nuclear safety and provide a structured approach to determining whether the safety case has been implemented adequately through the system being inspected.

LC 10 requires Sellafield Limited to make and implement adequate arrangements for suitable training for all those on site who have responsibility for any operations which may affect safety.

LC23 requires Sellafield Limited to produce an adequate safety case to demonstrate the safety of its operations, and to identify the conditions and limits necessary in the interests of safety.

LC24 requires Sellafield Limited to ensure that all operations which may affect safety are carried out in accordance with written instructions.

LC27 requires Sellafield Limited to ensure that a plant is not operated, inspected, maintained or tested unless suitable safety mechanisms, devices and circuits are properly connected and in good working order.

LC28 requires Sellafield Limited to make and implement adequate arrangements for the regular and systematic examination, inspection, maintenance and testing of all plant which may affect safety.

LC34 requires Sellafield Limited to ensure, so far as is reasonably practicable, that radioactive material and radioactive waste on the site is at all times adequately controlled or contained so that it cannot leak or otherwise escape from such control or containment.

The inspection was performed in accordance with ONR guidance (detailed in ONR inspection guidance) available at:

The inspection was focussed on civil structures, therefore LC27 was not directly relevant and hence not rated. Also, the implemented LC24 arrangements did not allow an assessment of LC34 which is therefore not rated.

I identified minor shortfalls in relation to LC10, 23 and 28. I provided regulatory advice and will follow up with a level 4 (lowest level) regulatory issue.

I identified a shortfall in the written instructions (LC24). I provided regulatory advice and will take this shortfall through ONR’s Enforcement Management Model to decide on any further follow up action.

On the basis of the evidence sampled at the time of inspection, I judge that Infrastructure Utilities has adequately implemented those safety case claims that relate to the civil structures or roads, bridges and pipebridges.


Overall we judged that the Structures (Roads, Road Bridges and Pipebridges) adequately fulfil the requirements of the safety case.

The inspection was focused on civil structures and therefore LC27 and LC34 were not directly relevant and were not rated.

We were broadly satisfied with implementation of LC10, LC23 and LC28 which were rated GREEN. A number of deficiencies were noted which have been incorporated into either observations/advice or level 3 (Pipebridges)/ level 4 (Roads & Bridges) regulatory issues.

We judged that the absence of the implementing instruction (SEL/176/6/SSS/CIVIL/003) is a specific significant weakness identified in implementation of pipebridge safety case requirements and therefore an AMBER (seek improvement) rating is appropriate. We are satisfied that the complimentary local and house rules provide sufficient prompt to produce and implement an adequate risk assessment for breaking containment and halting liquor transfers. We provided regulatory advice in relation to this shortfall and will take this through ONR’s Enforcement Management Model to decide on any further follow up action.