- Site: Sellafield
- IR number: 19-056
- Date: July 2019
- LC numbers: 22
Executive summary
Purpose of Intervention
On the 17 July 2019 the Office for Nuclear Regulation (ONR) undertook an intervention on the Sellafield site to inspect Sellafield Ltd’s (SL) readiness to commence the operation of the Finishing Line 4 (FL4) Repack Glovebox Facility for the over-packing of Type 1 Packages within SNM North.
Within SL’s SMN inventory there is a population of multi-layered packages currently stored within a bespoke SNM store. The store is located in a facility within the SNM-North (SNM(N)) complex.
Operation of the store and the new Finishing Line 4 (FL4) repack glovebox facility within SNM(N) is key to SL being able to meet its objective of risk reduction and continued safe storage of the nuclear material until a new treatment facility becomes available to prepare the material for safe longer term storage. The purpose of the intervention was to inspect SL’s implementation of its safety case under its Licence Condition (LC) 22 arrangements for this project and gain assurance that, SL is in a state of readiness to safely commence the proposed modification. The findings of the intervention will be used to inform the regulatory decision on SL’s request for ONR’s agreement to commence the proposed modification - FL4 Repack Glovebox Facility for the over-packing of Type 1 Packages within SNM North.
Interventions Carried Out by ONR
The scope of this intervention was to inspect FL4 Repack Glovebox Facility from a people, plant and processes perspective and assess the licensee’s readiness to safely commence active commissioning and operation of FL4. The scope of ONR’s intervention was outlined and agreed prior to the inspection.
The readiness inspection was undertaken against LC 22 ‘Modification or experiment on existing plant’, which requires the licensee to make and implement adequate arrangements to control any modification or experiment carried out on any part of the existing plant or processes which may affect safety.
The inspection comprised desktop-based discussions and facility inspection. It was undertaken against LC 22 in accordance with ONR guidance Technical Inspection Guide (TIG) NS-INSP-GD-022, LC22: Modification or experiment on existing plant, Revision 4, January 2018.
Explanation of Judgement if Safety System Not Judged to be Adequate
N/A – This was not a safety system inspection.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
Based on the evidence sampled during this intervention, I judge that SL’s implementation of its safety case under its LC 22 arrangements as Green (no formal action). With respect to ONR’s TIG NS-INSP-GD-022, SL adequately demonstrated:
- The modification is under the control of plant management and being managed in accordance with the established arrangements. Operational learning has been reviewed and used to inform the modification’s implementation. This was evidenced by the use of previous similar repacking operations and trails to inform how the cans will be processed.
- A systematic approach has been taken to the identification and delivery of personnel competence including assurance of this competence. This was evidenced through review of training materials, discussion with SL Training team, and Duly Appointed Person (DAP) and Operators.
- Suitable and sufficient instructions have been written and validated to support reliable human performance of the operations and there is an adequate system for the validation and verification of important operator actions. This included the adequacy of arrangements for off normal/fault/emergency situations. This was evidenced by plant walk-throughs and discussion with DAP’s and Operators of the steps identified in the Operating Instruction for FL4.
- Suitable and sufficient operational controls and safety measures are in place and available; this was evidenced by a detailed walk-down of the FL4 Transfer Table and Transfer Trolley arrangement with castell key security. SL provided adequate assurance to ONR that once FL4 operations commence, the Transfer Trolley and Castell Key will be maintained under SL’s existing asset management arrangements.
- Adequacy of the existing facility ventilation system to support FL4 operations. This was evidenced through discussions on the ventilation System Health Report and the EIM&T strategy with the SL System Health Engineer.
- That recording the amount of any PVC remaining on the legacy inner cans is adequately managed and will be used to inform the package EIM&T strategy during storage.
- Command and control arrangements including responsibilities are clearly defined and recognised, with adequate control and supervision. This was evidenced through discussion with DAP’s and Operators who articulated the arrangements for enhanced supervision during initial operation of FL4.
No shortfalls were identified during the inspection that would prevent permission being granted for the proposed modification.
In relation to SL’s overall state of readiness to commence the proposed modification; ONR observed that SL needs to close out a number of findings identified in its Hazardous Area Readiness Review (HARR) conducted by the SL Nuclear Independent Oversight (NIO) prior to commencing Active Commissioning and Operations of FL4. Based on this intervention, ONR is satisfied that SL is in control of the closure of these findings, and there is a robust hazardous activity readiness review process in place to confirm completion prior to active commissioning and operations. These include, completion of the safety case readiness review by the Safety Case team, correction of inconsistencies / misalignments of the Clearance Certificate, completion of the security door/camera commissioning test documentation, completion of operator training and submission of NIO’s observation record.
Conclusion of Intervention
Based on our findings from the available evidence, we judge that SL’s implementation of its safety case under its LC22 arrangements, and related to the Plant Modification Proposal process, is adequate in this instance. From the evidence sampled, no shortfalls were identified that would prevent permission being granted for SL to commence the proposed modification.
In relation to SL’s state of readiness, this inspection identified some areas that remain to be completed. ONR is satisfied that none of these are safety significant and that SL has plans in place to complete prior to active commissioning and operation of FL4. This intervention provided ONR confidence that SL is in control of the completion of these planned activities and there is a mature HARR process in place to confirm completion of identified findings prior to active commissioning and actual FL4 operations being authorised by the duty holder. I judge that an inspection rating of GREEN is merited.