- Site: Sellafield
- IR number: 19-073
- Date: August 2019
- LC numbers: 15
Executive summary
Purpose of Intervention
The Office for Nuclear Regulation (ONR) undertakes all regulatory interactions with the Sellafield Site Licensee (Sellafield Limited, SL) against a strategy defined by the ONR Sellafield, Decommissioning, Fuel and Waste (SDFW) Division. Objective 12 is concerned with the proportionate assessment of Periodic Safety Reviews (PSR). At Sellafield PSR are referred to as Long Term Periodic Review (LTPR).
The fundamental purpose of a PSR is to ensure that at any stage in its operational lifecycle, the facility remains adequately safe, whilst operating in compliance with a current and cogent safety case.
The purpose of this intervention was for ONR to assess the adequacy of the SNM (N) storage facility1 LTPR and to ensure that SL is taking the necessary steps to continue to operate and maintain the plant in a manner that ensures that the plant risks are as low as reasonably practicable (ALARP).
The three broad objectives of this intervention were to:
- Gain confidence that SL has undertaken an adequate LTPR, which takes into account lessons learnt and future foreseeable challenges.
- Gain confidence that the extant facility arrangements and the safety case are suitable and sufficient, and mitigate shortfalls awaiting improvements.
- Establish if SL has credible resolution plans to implement improvements identified by the LTPR.
The inspection also provided an opportunity for ONR to gather information on the storage facility and the contribution that the plant could make to ONR’s strategic priority at Sellafield (high hazard risk reduction).
Interventions Carried Out by ONR
On 20-21 August 2019, ONR carried out a one and a half day inspection of Licence Condition (LC) 15 compliance in the storage facility. The ONR inspection team was assembled following a review of the LTPR by the ONR Project inspector. Each ONR inspector reviewed the LTPR and developed lines of inquiry to inspect with SL:
- LTPR process and shortfalls management
- Safety case
- Plant and engineering
- Leadership and Management for Safety (LMfS)
The intervention comprised of:
- Sampling the process and technical aspects of the application of SL LTPR arrangements and associated documents.
- Discussions with appropriate members of SL staff with reference to the identified lines of inquiry.
- The LTPR inspection included a facility walk down of the main storage building and its extension, air supply plenum systems and air extract plenum systems. ONR was accompanied on the walk down by the Safety Case Manager, the Safety Case Lead and two System Engineers. This was useful as it allowed a good discussion of the facility function/challenges and also allowed the comments made by SL during the LTPR process to be better understood and appreciated.
LC 15 requires the licensee to make and implement adequate arrangements for the periodic and systematic review and reassessment of safety cases. The following ONR guidance was used:
- NS-INSP-GD-015, Revision 3, Periodic Review.
- NS-TAST-GD-050, Revision 7, Periodic Safety Reviews (PSR).
- ONR Safety Assessment Principles (SAP), 2014.
Explanation of Judgement if Safety System Not Judged to be Adequate
This was not a system based inspection; therefore no judgement has been made on the adequacy of the implementation of any specific part of the safety case.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
Based upon sampling of submitted documents, discussions with SL staff and a facility walk-down, ONR considers that SL has undertaken an adequate LTPR of the storage facility. The inspection did not reveal any matters of substantive concern that had not already been identified by SL as part of its own review or were already being progressed as part of its routine business. Closure of the shortfalls identified by SL will be monitored by the ONR LTPR inspector as part of normal, post inspection duties.
ONR considers that:
- SL adopted a suitably proactive approach to the storage facility LTPR
- Arrangements to address the actions identified during the LTPR are adequate.
As part of its LC15 arrangements SL will produce a Confirmation of Safety Letter to confirm that the facility has adequately implemented the LTPR and that risks have been reduced to ALARP.
Overall ONR is satisfied that:
- SL has carried out an adequate LTPR, which has taken into account lessons learned and foreseeable future challenges.
- The LTPR has identified issues that require attention, and arrangements are in place to address the outstanding actions.
Conclusion of Intervention
Based on the evidence sampled during the inspection, ONR considers that SL has effectively implemented its arrangements for compliance with LC15. ONR therefore judges that an inspection rating of Green (no formal action) is appropriate for compliance against LC15 (periodic review).