Office for Nuclear Regulation

Sellafield – LC21 inspection of D-Bay commissioning

Executive summary

Purpose of Intervention

This inspection was undertaken on 11 September 2018 at the Sellafield Limited nuclear licensed site in Cumbria.

The purpose of the inspection was to examine the arrangements for commissioning as applied to the First Generation Magnox Storage Pond D Bay sludge retrieval project. This was to verify that the Licence Condition 21 arrangements are adequate, and have been adequately implemented on the project. This intervention supports ONR’s assessment related to giving permission to SL to commence commissioning and operation of D bay Retrievals.

Interventions Carried Out by ONR

I carried out an inspection of the Licensee’s arrangements for compliance with Licence Condition 21 on the FGMSP D Bay project. Licence Condition 21 requires the licensee to make and implement adequate arrangements for the commissioning of any plant or process which may affect safety.

This inspection was carried out against the requirements of Licence Condition 21 and ONR’s relevant inspection guidance as defined in NS-INSP-GD-021. The inspection was conducted through office-based examination of procedures and records, interviews with staff and observation on the plant. The inspection was undertaken by the Site Inspector supported by an ONR Human Factors specialist inspector. Human Factors specialist support was selected for the inspection, to inspect operator controls, training and procedures against relevant good practice.

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A – This was not a Systems Based Inspection.

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

The licensee presented its arrangements for compliance with Licence Condition 21, and how these have been applied to the D-Bay sludge retrievals project. Although the Plant Modification Proposal and safety case for active commissioning of the sludge system is a Category C modification, SL has applied its arrangements as if the consequences were a higher category modification.

SL has appointed a number of Commissioning Team Leaders (CTLs) to Control, witness and record tests carried out in accordance with 21(5), and also a Commissioning Manager and Pre-Operations Manager to oversee and assess the results of any tests in accordance with LC21(5). I reviewed the arrangements for supervising tests and managing records and these arrangements were found to be adequate when compared to ONRs inspection guidance.

I reviewed the key documents for planning and conducting commissioning activities, including the commissioning strategy, inactive commissioning plan and commissioning schedule, as well as the commissioning work sheets (CWS) and instructions used on the plant, and I found these all to be applied appropriately on the project. I judged these to meet the requirements of ONRs inspection guidance.

I observed commissioning activities on the plant and reviewed the supervision and permit to work arrangements, and found these to be well controlled and compliant with SLs own arrangements.

I sampled a number of commissioning records for commissioning of the gantry and camera systems, and found these to be in order with SLs arrangements, and compliant with the expectations detailed in ONRs inspection guidance for LC21(6).

SL demonstrated that the Commissioning Sub-Committee (CSC) considers both the inactive and active plant commissioning reports (IPCR & APCR), and also considers the safety case, in-line with LC21(7) I & II expectations. A defined set of acceptance criteria links the safety case to the commissioning reports. I reviewed these arrangements as applied to the project and judged these to be adequate when compared to ONRs inspection guidance.

I checked the Suitably Qualified and Experienced Person (SQEP) evidence for the commissioning team, supervisors and managers, and I found these to be in compliance with Sellafield Ltd. Licence Condition 12 arrangements. 

I reviewed the arrangements Fault Observations (FOBs) for controlling issues, technical queries and plant changes during commissioning and found these to be adequately controlled.

I reviewed the access control arrangements through the sub-change room, which were adequate for the current hazards, however these will need to be updated to consider the revised hazards before active commissioning commences. SL clarified the process it will go through to consider any revisions required to the access arrangements. SL agreed to send a copy of the updated arrangements that will be in place prior to active commissioning. These will be reviewed by ONR prior to releasing the permission for active commissioning of the D-Bay sludge retrievals system.

Conclusion of Intervention

Overall I judged compliance with LC21 to be green based on the inspection scope and sample of evidence examined. The licensee demonstrated compliance with its legal duties in this context, and no significant shortfalls were identified. Minor actions were agreed for the licensee to provide additional documentation to ONR in support of the assessment to release the hold point for active commissioning. These will be reviewed by ONR before ONR releases the hold point.