Executive summary
Date(s) of inspection:
February 2026
Aim of inspection
This intervention was undertaken across the AWE Nuclear Security Technologies Explosives Business Unit (XBU) and aligns with the Office for Nuclear Regulation (ONR) 2025/26 integrated intervention strategy for the weapons sub-division.
The activity supports Theme 2 'Improved Safety Leadership and Culture' as set out within ONR's sub-strategy and links with the below key sub-division objective (KSO) and desired regulatory outcomes (DRO):
- KRO.1 - AWE Plc to demonstrate effective implementation of adequate arrangements across key themes.
- KRO.4 - ONR holds AWE to account on behalf of the public for providing assurance that activities that may impact upon safety, are planned, and conducted in accordance with the appropriate legislative requirements and that all risks have been reduced to as low as reasonably practicable.
- DRO.2 - Operational Activities & Existing facility upgrades: Demonstration that AWE is implementing adequate strategies, plans and arrangements for safe delivery of current operations and existing facility upgrades.
The aims of this inspection were to:
- Assess the adequacy of arrangements and their implementation with respect to the control and supervision of high hazard operations.
- Obtain evidence of XBU’s approach to ensuring the suitable and sufficient personnel are appointed to control, supervise and undertake high hazard operations.
- Obtain evidence of how risks associated with high hazard operations are assessed and controlled as low as reasonably practicable.
Subject(s) of inspection
- IRR17 - Rating: Amber
- LC26 - Control and supervision of operations - Rating: Amber
Key findings, inspector's opinions and reasons for judgement made
The ONR inspection team attended the XBU, which is located on the AWE Aldermaston nuclear licensed site on 11 February 2026 to undertake this inspection of control of works and ionising radiation regulations (IRR) compliance. The inspection team comprised radiological protection and criticality, and human factors specialist inspectors, and the site inspector.
A number of documents were requested in advance of the inspection and these were received in a timely manner and were sampled as part of preparation activities. The inspection followed a high-level scope that had been proposed by ONR and shared with XBU in advance of the inspection.
The inspection targeted aspects of Licence Condition 26 compliance and sampled the adequacy of high-level and local arrangements and their implementation with a specific focus on high hazard radiography operations.
Elements of good practice were identified as part of the inspection. For example, the addition of the Search and Lock Up System (SALUS) in a radiography facility, to reduce the risks of exposing personnel to high levels of ionising radiation from X-ray operations.
An area for improvement was identified in relation to XBU ensuring alignment (as appropriate) with the company procedures and guidance, as part of the in-progress update of its Plan of the Week (PLoW) and Plan of the Day (PloD) Terms of Reference (TOR).
A number of shortfalls were identified and raised with the dutyholder in relation to the following areas:
Control of works:
- the competency and suitability of personnel responsible for undertaking high hazard radiography operations was not being adequately managed and controlled
- the implementation of the PLoW did not effectively consider high hazard tasks and adequately deconflict activities in the interest of ensuring safety
Ionising Radiation Regulations 2017:
- the risk assessments associated with radiography operations were not suitable and sufficient
- necessary steps to restrict exposure to ionising radiation had not been taken
Separate to the scope of this inspection, a concern was raised with the dutyholder in regard to the appropriateness of signage for a designated construction site. This will be followed up separately by the ONR site inspector.
Based on the areas sampled, significant shortfalls were identified during this inspection and an amber rating (Seek Improvement) was awarded. ONR Regulatory Issues have been raised to ensure that the identified shortfalls are adequately addressed by the dutyholder.
Conclusion
This inspection identified significant shortfalls with respect to compliance with Licence Condition 26 (Control and supervision of operations) and the Ionising Radiation Regulations 2017.
This inspection was rated amber (Seek Improvement).
This rating is in line with the established ONR guidance as follows:
- Significant shortfall against an identified relevant good practice when compared with appropriate benchmarks
- Inconsistent standards for managing risks to workers; with some key relevant statutory provisions not met.
- Deficient arrangements for compliance with legal requirements.
The shortfalls have been shared with the dutyholder as ‘Findings’ and two ONR Regulatory Issues have been raised.