Sellafield readiness inspection
- Site: Sellafield
- IR number: 19-093
- Date: September 2019
- LC numbers: N/A
Purpose of Intervention
On 24-25 September 2019 the Office for Nuclear Regulation (ONR) undertook an intervention (supplemented by a Conventional Health & Safety Intervention on 19 September 2019) on the Sellafield site to inspect Sellafield Ltd’s (SL) readiness to commence construction of Sellafield Product and Residue Store Retreatment Plant (SRP) base slab, main building and Sellafield Product and Residue Store (SPRS) to SRP elevated transfer tunnel.
On completion of spent nuclear fuel reprocessing in 2020 and national consolidation activities, SL will house a significant stockpile of Special Nuclear Material (SNM) held in a range of packages. Left untreated, these packages (consisting of various layered containment can systems) are at risk to loss of containment faults via a range of mechanisms and therefore need to be retreated and/or repackaged in alignment with their substantiated lifetime.
Construction of a new retreatment plant (SRP) is key to SL being able to meet its objective of risk reduction and safe storage of the nuclear material and will serve to provide treatment and re-packaging capability 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) 19 arrangements for this project and to gain assurance that, SL is in a state of readiness to safely commence the proposed construction activities. The findings of the intervention will be used to inform the regulatory decision on SL’s request for ONR’s agreement to commence the construction of SPRS Retreatment Plant (SRP) base slab, main building and SPRS to SRP elevated transfer tunnel.
Interventions Carried Out by ONR
The scope of this intervention was to inspect the SRP project from a people, plant and processes perspective and assess the licensee’s readiness to safely commence construction of SPRS Retreatment Plant (SRP) base slab, main building and SPRS to SRP elevated transfer tunnel. A team comprising the ONR Project Inspector, Civil Engineering Specialist Inspector and Supply Chain and Quality Assurance (QA) Specialist Inspector carried out the inspection.
Supplementary to this, ONR inspected SL’s arrangements from a conventional health & safety perspective via a separate intervention on 19 September 2019, the output of which, feeds directly into this intervention report.
The readiness inspection was undertaken against LC 19 ‘Construction or installation of new plant’, which requires that the licensee shall make and implement adequate arrangements to control the construction or installation.
The inspection comprised desktop-based discussions, construction site inspection and concrete batching plant inspection. It was undertaken against LC 19 in accordance with ONR guidance Technical Inspection Guide (TIG) NS-INSP-GD-019, LC19: Construction or installation of new plant, Revision 5, November 2018.
Explanation of Judgement if Safety System Not Judged to be Adequate
Key Findings, Inspector's Opinions and Reasons for Judgements Made
No matters were identified requiring immediate regulatory attention during the conduct of the inspection.
Based on the evidence sampled during this intervention, I judge that SL’s implementation of its safety case under its LC 19 arrangements as Green (no formal action) With respect to ONR’s TIG NS-INSP-GD-019, SL adequately demonstrated:
- The SRP project is under adequate control by SL management and being managed in accordance with the licensee’s established arrangements. Furthermore, adequate organisational and governance arrangements exist to manage the pour for the concrete raft foundation. This was evidenced through discussion with SL management who articulated clear reporting lines to senior management and external performance boards, internal performance measures, defined competency criteria for the construction team and supporting competency records with Intelligent Client (IC) requirements executed in the said roles.
- Operational learning has been reviewed and used to inform the implementation of the safety case. This was evidenced by SL’s inclusion of the Internal Certification Group (ICG) Quality Control Engineer early in the project design arrangements, as well as establishing an ICG team for quality control inspections so that supply chain manufacturing activities could be assessed in a timely manner.
- A systematic approach has been taken to the identification and delivery of personnel competence. This was evidenced through review of training records, discussion with SL management team and operators.
- The SRP project has adequate arrangements for the management of the safety case and design specification. The management of residual design risks is controlled using approved procedures, a design risk register and hosting meetings between relevant team members to agree a safe method of construction without compromise to the design.
- Safety case requirements with regard to the construction of the raft foundation have been implemented; evidenced through discussions with the SL management team and examination of the Project Specific Verification Schedule for the Slab Foundations.
- The SRP project has adequate arrangements for managing the execution of civil construction works including: the execution of SRP’s QA arrangements and supply chain oversight for concrete pours; ensuring materials used in the raft construction have the appropriate degree of QA certification and that sufficient testing will provide confidence that materials will meet the design requirements; the management of the on-site concrete batching plant. The above was evidenced through demonstration by SL that:
- SRP control arrangements for the execution of civil works is managed by a combination of pre-engineering reviews with the contractor (to set expectations and agree objectives), supported by the production of a series of contractor produced, SL approved method statements. Additional control consists of inclusion of key activities within QPs with appropriate verification codes / hold points. These act as internal permission points requiring SL sign off before commencement of the next activity.
- SL has contingency plans in place to ensure a continuous concrete pour in the unlikely event of an onsite batching plant failure.
- SL’s Quality Assurance arrangements, SL and suppliers Quality Plan (QP) for the concrete pour, and associated arrangements exist for cascading the specification through the supply chain and the incorporated operational experience / learning from experience (OPEX/LFE) to improved SRP’s project control and arrangements.
- Verification process are in place for defined certification criteria in accordance with accepted British standards, UKAS and SL expectations as well as proposed arrangements for targeted assurance activities on the manufacture of specific items.
- The relevant certification by independent third parties to international standards and industry criteria of the batching plant, segregation and verification of material from receipt inspection, monthly calibration conducted by an independent third party and a controlled process flow from initial concrete mix request to post mix design verification.
- The SRP project has adequate arrangements to effectively discharge its duties under the Construction Design and Management Regulations 2015. This was evidenced via discussions with site personnel and inspection of management system documentation and the actual construction operations that were taking place at the time of the visit.
Based on the evidence sampled I am satisfied that the licensee has adequate arrangements in place to manage the process of implementing the SRP safety case.
Overall, I am satisfied that SL has appropriate arrangements to enable it to commence construction of SPRS Retreatment Plant (SRP) base slab, main building and SPRS to SRP elevated transfer tunnel.
Conclusion of Intervention
Based on ONR’s findings from the available evidence, I judge that SL’s implementation of its safety case under its LC19 arrangements is adequate in this instance. No shortfalls were identified that would prevent permission being granted for SL to commence the proposed construction activities.
I am satisfied that SL has appropriate arrangements in place to enable it to commence construction of SRP and for implementing its safety case. I therefore consider, noting the ONR guidance on inspection ratings, that an inspection rating of Green (no formal action required) is merited here.