Executive summary
Date(s) of inspection:
August 2025
Aim of inspection
To judge the adequacy of implemented NNB GenCo arrangements to:
Monitor and manage safety significant structures, systems or components, where ageing management is identified as a risk, or where it is evident.
Obtain advice from experts or suitably qualified and experienced personnel to inform ageing and/or corrosion management strategies, risks and mitigations.
Plan, manage and monitor construction related plant, temporary structures and equipment installed on-site, and engagement with its contractors in this regard and how risks are identified and managed.
Subject(s) of inspection
- CDM 15 - Rating: Green
- LC19 - Construction or installation of new plant - Rating: Green
- LC28 - Examination, inspection, maintenance and testing - Rating: Green
- Lifting / LOLER - Rating: Green
- Provision and Use of Work Equipment Regulations 1998 (PUWER) - Rating: Green
- Working at Height - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
The inspection considered a wide range of equipment and temporary structures located across the construction site, from the concrete batching plant to mast-climbing work platforms. The inspection included a series of presentations by personnel from NNB GenCo (HPC) Ltd (NNB), Bylor Joint Venture (Bylor) and the MEH Alliance (MEH), together with visits to a range of areas on site.
The inspection covered the management of ageing in both temporary equipment and structures used during construction and permanently installed equipment, although this was less of a focus. I spent the majority of the inspection on site, observing various locations and work areas. These included:
- Concrete Batching Plant
- Unit 2 Heat Sink construction area
- Operational Service Centre (HBX) construction area
- Bylor's Maintenance Area
- Unit 1 Diesel Building construction area
- Unit 1 Safeguard Building (HL1) construction area
During the inspection I identified several areas of good practice. These included NNB's improved management and monitoring of cranes across the site, Bylor's management system for the control of assets, the MEH management system for scaffolding and, more generally, both NNB and Bylor's improved arrangements for the planning, management and monitoring of construction equipment.
I noted a number of points where I advised either NNB or Bylor to implement improvements, and raised a minor Regulatory Issue in relation to the inoperability of several self-closing gates around the site, in particular where they provide a barrier between people and plant or vehicles.
My inspection found that in relation to the sample undertaken, NNB with support from Bylor and other contractors has improved and is adequately implementing its arrangements for the ageing management of construction equipment and temporary structures. I found that NNB is engaging with suitably qualified and experienced personnel in order to derive and implement its arrangements, and that it appears to have appropriate arrangements to plan, manage and monitor the impact of ageing on construction related equipment and structures.
Conclusion
Following my inspection, I have made the following judgements:
- The crane maintenance meeting appears to enable suitable decisions to be made by the Principal Contractor, informed by its Contractors. It assists the Principal Contractor to effectively plan, manage and monitor crane usage and replacement, along with the maintenance of such.
- Following the incident with Crane 1L5, an extent of condition review has been undertaken by NNB and its key Tier 1 contractors. This review has been thorough and has fed directly into revised arrangements for ageing management.
- There is evidence of a focus on risk in relation to ageing within NNB and Bylor's arrangements. There is also a clear engagement with suitably qualified and experienced personnel and organisations in the development of ageing management strategies. This provides confidence that improvements have been made and that there should be visible improvements in construction equipment management across the site as a result.
- NNB has made and implemented improvements in its planning, management and monitoring of both temporary and permanent equipment and structures across the site and has engaged with its contractors accordingly. This provides confidence that it can demonstrate compliance with the requirements of the Construction (Design and Management) Regulations 2015.
- There were several areas where I noted that hazards required addressing. Following the inspection, NNB has provided sufficient evidence that these have been addressed.
The following items require follow-up by ONR with NNB. This will be done during future planned engagements:
- NNB could not provide care and maintenance records for the low-head safety injection pump that was currently being installed. The responsibility for care and maintenance has not yet been formally transferred to NNB. I will follow this up with the ONR Installation and On-site Fabrication inspector to ensure appropriate care and maintenance activities are being undertaken by NNB.
- Balfour Beatty could not demonstrate that maintenance personnel and thorough examination personnel were independent and committed to review its arrangements and management of contractors. The ONR site inspector will follow this matter up with NNB in relation to the extent of condition.
- Due to the corrosion observed on the outside of Bunkers LB5 and LB6, ONR intends to follow up on the outcome of the current engineering assessments at future CECA meetings.
In relation to the self-closing gates across the site, NNB's arrangements confirm that these should be in place and in working order. Therefore, I judge that NNB is currently not compliant with its own standards. I have raised a minor Regulatory Issue [RI-12690] to ensure NNB addresses this in a timely manner.
Although there were minor deficiencies in compliance arrangements, in particular in relation to the self-closing gates, I have rated this inspection GREEN in accordance with ONR TIG NS-INSP-GD-064 because relevant good practice was generally met and no significant issues were identified.