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Sellafield - Licence Condition 35 (LC35) arrangements inspection

  • Site: Sellafield
  • IR number: 21-040
  • Date: June 2021
  • LC numbers: 35

Executive summary

Purpose of Intervention

The Office for Nuclear Regulation (ONR) undertakes all its regulatory interactions with the Sellafield site licensee, Sellafield Limited (SL), against a strategy defined by the ONR Sellafield, Decommissioning, Fuel and Waste (SDFW) Division.  In accordance with this strategy, a planned inspection of SL’s corporate site-wide arrangements for compliance with Licence Condition 35 (LC35) “Decommissioning” was carried out on 15-16 June 2021.

The objectives of the inspection were to determine the adequacy, judged against the relevant expectations of ONR, of:

  • SL’s corporate site-wide arrangements to comply with LC35;
  • Experience and training of selected persons assigned responsibility under SL’s corporate site-wide arrangements to comply with LC35;
  • Records (Licence Condition 6 (LC6) “Documents, records, authorities and certificates” refers) made to demonstrate compliance with LC35;
  • SL’s means of gaining internal assurance of compliance with LC35, and;
  • SL’s learning from incidents related to decommissioning.

Clauses LC35(3), LC35(4), LC35(5), LC35(6) and LC35(7) each provide ONR with a basis to invoke selected primary powers (that is, Approval, Specification, Consent and Direction). A shortfall relating to SL’s arrangements for responding to ONR’s use of primary powers was identified during a previous arrangements inspection and captured in a Regulatory Issue (RI). To ensure a consistent approach, the scope of this RI was extended to cover all relevant LCs, including LC35. This residual matter was therefore not considered further during this inspection.

Interventions Carried Out by ONR

The inspection comprised discussions with Sellafield staff and reviews of a targeted sample of Sellafield’s documentation. The scope and priorities of the inspection took into account intelligence gained from other ONR interventions.

The inspection was carried out by the Sellafield Compliance Intelligence and Enforcement (SCIE) Corporate Arrangements Inspector with support from: a Nuclear Liabilities Regulation (NLR) Equivalence Inspector; a NLR Specialist Inspector; and, a Mechanical Engineering Specialist Inspector. The Environment Agency (EA) and a member of Sellafield’s Nuclear Intelligence and Independent Oversight (NI&IO) function also participated.

ONR expectations particularly relevant to the inspection included the extant revisions of:

  • Nuclear Safety Technical Inspection Guide (TIG) NS-INSP-GD-035, “LC35 Decommissioning”.
  • Safety Assessment Principles for Nuclear Facilities (SAPs), particularly DC.1-DC.9.
  • Nuclear Safety Technical Assessment Guide (TAG) NS-TAST-GD-026, “Decommissioning”.
  • TAG NS-TAST-GD-65, “Function and Content of the Nuclear Baseline”.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable, as this was not a System Based Inspection.

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

I considered that the engagement prior to and during the inspection allowed a meaningful inspection of SL’s corporate site-wide arrangements for LC35 compliance and all the inspection objectives were met.

On the basis of the evidence sampled before and during this inspection, I identified the following areas of good practice in respect of SL’s arrangements:

  • A relevant “Mandatory Standard” was in place, which enabled a top-down line of sight from SL’s legal obligations to the relevant arrangements. Further refinement was needed for this to recognise all the applicable obligations.  In addition, refinement is needed to improve the bottom-up line of sight from the arrangements to the legal obligations.
  • Collaborative working between SL and the Low Level Waste Repository (LLWR) to consider the potential opportunity for future near surface disposal of Sellafield’s decommissioning wastes.
  • A risk-informed and prioritised set of reviews are being undertaken of historic facility-level Decommissioning Mandates and Preliminary Decommissioning Plans to improve their quality and consistency.
  • Development of Decommissioning Engineering and the Decommissioning Engineer role, to strengthen the links between LC35 arrangements, lifecycle asset management, robustness of key dates in the site master schedule and facility safety cases.
  • Openness about the challenges faced, for example recognition that the baseline decommissioning ambition for Sellafield cannot be delivered by the site’s current waste management infrastructure.
  • Development of improved arrangements for Post Operational Clean Out (POCO) ahead of the transition of the Thermal Oxide Reprocessing Plant (THORP) out of operations.
  • Collation of lessons learned from the POCO of THORP and another plant and dissemination of the emergent learning to inform plans at other plants.
  • Given the joint regulatory interests of ONR and the EA in decommissioning, that SL is taking on board feedback from a recent EA desktop review of the Sellafield decommissioning strategy.

I identified the following areas of good practice relating to the delivery of this inspection:

  • The knowledge and professionalism of all those we spoke too.
  • Thorough preparation for the inspection and timely responses to ONR information requests.
  • Effective use of information technology to share information.
  • Good observation of COVID-19 protocols at the inspection venue.

On the basis of the evidence sampled during this inspection, I identified the following items of regulatory advice:

  • ONR noted that some terms [for example, Intelligent Customer (IC)] were not consistently used throughout relevant documents. SL was advised to review the terminology used in these documents and to also check for consistent use of relevant terms throughout all relevant documents (for example, documents used for compliance with other Licence Conditions which interface with the LC35 arrangements).
  • During discussion of SL’s definition for “Plant which may affect safety”, ONR advised that Licence Condition 16 (LC16) “Site plans, designs and specifications” was relevant since the Site Plan shows the location of every building or plant on site which may affect safety. ONR also advised that the LC16 Schedule contained relevant information. ONR further advised that LC35 should be integrated with the relevant aspects of Licence Condition 15 (LC15) “Periodic review”, noting that periodic reviews of safety should consider the whole of the remaining life of the facility, including future POCO and decommissioning.
  • ONR advised that the Decommissioning IC and the POCO IC roles should be renamed since they do not relate to IC responsibilities according to the widely accepted definition of IC.

On the basis of the evidence sampled before and during the inspection, I identified the following regulatory findings:

  • The Decommissioning Mindset Arrangements (DMAs) did not fit within the Sellafield Limited Management System (SLMS) document hierarchy and their relationship to the LC35 arrangements was unclear. In addition, it was not clear whether the DMAs were; comprehensive; quality assured; consistently applied, or; appropriately maintained.
  • Sellafield was unable to demonstrate that the information from the site master schedule that was used to populate the Decommissioning Integrated Strategic Plan (DISP) was adequately justified and quality assured.
  • Prior to the inspection SL identified a shortfall in that the Decommissioning Subject Matter Expert (SME), Decommissioning IC and POCO IC roles were not recognised on its nuclear baseline and that the responsibilities of the two ICs were not consistent with the accepted definition of an IC.  ONR considered this to be a gap against its nuclear baseline expectations.
  • Sellafield published detailed arrangements for POCO, which included a systematic approach to identifying the optimal end-of-POCO state while taking account of the principles of As Low As Reasonably Practicable (ALARP), Best Available Techniques (BAT) and alignment of the scope of POCO to the ambition for future decommissioning. However, only high-level arrangements were in place for the later stages of decommissioning that will follow POCO.

I concluded that the shortfalls identified were minor when taken individually or as a whole. In this respect the most significant finding was considered to be the need for SL to demonstrate that the quality of information in the site master schedule was adequate to comply with ONR’s expectations for LC35. I will monitor SL’s response to the identified shortfalls by raising four Level 4 RIs.

The representatives of NI&IO and EA whom participated in the inspection were in broad agreement with the above outcomes.

The above regulatory advice and findings were shared with SL in a hot debrief at the end of the inspection and were acknowledged and accepted by key SL staff. The LC35 Process Owner recognised the outcomes of the inspection and agreed to address the RIs in a timely manner.

Conclusion of Intervention

Taking the above into account, I considered that an inspection rating of Green (No Formal Action) was merited, having noted the guidance in ONR documentation.