Office for Nuclear Regulation

Sellafield – Inspection ID: 50328

Executive summary

  • Inspection date(s): 4/10/22

Purpose of inspection

In accordance with the Office for Nuclear Regulation’s (ONR’s) Sellafield Strategy, each year ONR performs a series of planned compliance inspections of selected licence conditions, targeted at those facilities with significant importance to nuclear safety. One such system based inspection (SBI) was undertaken to assess the Magnox Encapsulation Plant (MEP)’s compliance with Sellafield Limited’s corporate arrangements for Licence Condition 10 (training), 12 (Duly authorised and other suitably qualified and experience persons), 23 (operating rules), 24 (operating instructions), 27 (safety mechanisms, devices and circuits), 28 (examination, maintenance, inspection and testing) and 34 (leakage and escape of radioactive materials and radioactive waste) on 4 and 5 October 2022.

The primary objective of this inspection was to enable ONR to form a view on the adequacy of the safety performance of the ventilation systems within the Magnox Encapsulation Plant (MEP), and the demonstrable achievement of a sampled set of safety related claims identified from the relevant parts of the safety case, to gain assurance that the ventilation system fulfils its safety function and that MEP has adequately implemented the safety case.

The inspection comprised discussions with Sellafield Limited staff, a targeted plant walkdown and a review of plant records and other documentation.

Subject(s) of inspection

The following actives were the subject of this inspection:

  • LC10 – Training
  • LC24 – Operating instructions
  • LC23 – Operating rules
  • LC34 – Leakage and escape of radioactive material and  radioactive waste
  • LC27 – Safety mechanisms, devices and circuits
  • LC28 – Examination, inspection, maintenance and testing

Key findings

ONR’s 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).

I identified minor shortfalls in relation to LC 10, 23 and 24. I provided regulatory advice and will follow up as part of normal business.

On the basis of the evidence sampled at the time of inspection, I judge that MEP has adequately implemented those safety case claims that relate to the ventilation system.

Judgements made

The Licensee has demonstrated that the Structures, Systems and Components (SSCs) which have been inspected as part of the MEP ventilation system are able to fulfil their safety function requirements adequately, in line with the requirements of the MEP safety case.

On the basis of the evidence sampled at the time of the inspection, I judge that the Magnox Encapsulation Plant (MEP)has adequately implemented the safety case for the ventilation system and the ventilation system currently fulfils its safety function. Noting the ONR guidance on inspection ratings, it is my opinion that an inspection rating of Green (no formal action) is appropriate for compliance with LC10, 23, 24, 27, 28 and 34.