- Site: Sizewell B
- IR number: 21-118
- Date: November 2021
- LC numbers: 17, 36
Executive summary
Purpose of Intervention
The purpose of this intervention was to conduct an ageing management inspection of EDF Energy Nuclear Generation Limited (EDF NGL’s) Sizewell B (SZB) power station. In 2021-22, the Office for Nuclear Regulation (ONR) is carrying out a Chief Nuclear Inspector’s (CNI) themed inspection on the management of ageing assets. This comprises a series of inspections across nuclear site licensees, the purpose of which is to seek evidence of sustainable programmes for the management of ageing assets against four themes: strategy, organisational capability, management of obsolescence, and ongoing investment in people, plant and processes. This inspection was conducted on 16-17 November 2021 and covered themes 2 and 4. It complements an inspection of themes 1 and 3 carried out on 6-7 October 2021.
Interventions Carried Out by ONR
ONR’s inspection focussed on the following themes:
- Theme 2: Commitment to ensure the right level of organisational capability to sustain specialist safety case and other technical capability to substantiate on-going safe operation; and
- Theme 4: Sustained focus and commitment to ongoing investment in plant, people and processes concerned with ageing management
The inspection considered organisational capability at SZB as well as NGL’s Central Technical Organisation (CTO), part of the Central Supports Functions (CSFs). It also considered NGL’s fleet-wide management arrangements and their application to management of ageing assets at SZB.
The inspection comprised discussions with NGL staff (both at SZB and in the CTO), a walkdown of ongoing investment projects at the site relevant to ageing, and a review of plant records and other documentation. The specific topics for the inspection were informed by the self-assessment conducted by NGL ahead of the inspection.
The inspection team comprised specialist inspectors in Leadership and Management for Safety (LMfS), the site inspectors for SZB, ONR’s Executive Director of Operations and a specialist inspector in safeguards. The inspection was rated against Licence Conditions 36 (Organisational Capability) and 17 (Management Systems). The primary ONR guidance used in this inspection was:
- NS-TAST-GD-049, Licensee Core Safety and Intelligent Customer Capability
- NS-TAST-GD 065, Function and Content of the Nuclear Baseline
- NS-TAST-GD-098, Asset Management
Key Findings, Inspector's Opinions and Reasons for Judgements Made
I tested the following specific aspects of NGL’s organisational capability: implementation of the arrangements for handover of plant systems from one system engineer to another, management of organisational capability (at both SZB and in the CTO), and implementation of NGL’s arrangements for intelligent customer oversight of contractors and suppliers. On system handover I found that SZB has markedly improved its arrangements for handover based around a system handover document, with supporting information, which complements the information held within the site’s databases. The documents are used, and found useful, by system engineers we spoke to. I noted that, contrary to NGL’s arrangements, the system handover documents are not always maintained up-to-date and therefore advised station management to clarify its expectations in this regard, with a focus on the tacit knowledge that is not available elsewhere. On organisational capability I found that both SZB and the CTO are conducting regular reviews of organisational resilience and taking action where needed to maintain capability. CTO has work in hand to give greater clarity on the allocation of resource which is seconded to EDF’s Technical Support Organisation (TSO), which also supports other EDF licensees. This is particularly important for SZB as this capability is largely Pressurised Water Reactor (PWR) specific. On intelligent customer, I found that engineers and project delivery staff had a good understanding of the components of the intelligent customer role and could give examples of its application. However, I advised that NGL should consider clarifying its definition and expectations for the role to ensure that staff understand their contribution to NGL’s intelligent customer capability and act in a well-coordinated manner.
I tested specific aspects of NGL’s arrangements for the management of ageing assets. This included SZB’s risk-based strategy for the management of ageing assets and obsolescence, and the implementation of the strategy in terms of investment delivery. NGL has developed ageing management investment delivery programmes to aid their assessment and maintenance of ageing assets and the obsolescence of parts. I found that SZB is taking appropriate action to adequately manage the risks to nuclear safety significant plant based on the sample tested. I also found SZB’s participation in international, high-value control and instrumentation (C&I) projects was providing positive benefits. I advised NGL that further benefits could be realised by closer links with the French EDF PWR fleet and benchmarking with other international PWR stations.
Conclusion of Intervention
I judge from the evidence sampled that EDF NGL is maintaining adequate organisational capability to support management of ageing assets at SZB. I have therefore assigned an inspection rating of Green (no formal action) against LC36.
I judge from the evidence sampled that EDF NGL is maintaining adequate arrangements for management of ageing assets at SZB. I have therefore assigned an inspection rating of Green (no formal action) against LC17.