Executive summary
Date(s) of inspection:
May 2026
Aim of inspection
In accordance with the Office for Nuclear Regulation’s (ONR’s) Sellafield Strategy, each year ONR performs a series of planned inspections to seek assurance of compliance against selected licence conditions, targeted at those facilities with significant importance to nuclear safety. One such inspection was undertaken at Special Nuclear Materials Value Stream South facilities (SNM (S)) within the Sellafield site in West Cumbria to sample evidence of implementation of Sellafield Limited's arrangements for compliance with Licence Condition (LC) 6 (Documents, records, authorities and certificates), 24 (Operating instructions), 25 (Operational records) and 26 (Control and supervision of operations) specifically to Residue to Waste (RTW) operations, in order to inform a regulatory judgement regarding the licensee’s compliance with its legal duties under the nuclear site licence.
In addition, to the above announced LCs inspection, and in response to incident BN2605A0166, I sampled evidence of LC 28 (Examination, inspection, maintenance and testing) implementation.
Subject(s) of inspection
- LC6 - Documents, records, authorities and certificates - Rating: GREEN
- LC24 - Operating instructions - Rating: GREEN
- LC25 - Operational records - Rating: GREEN
- LC26 - Control and supervision of operations - Rating: GREEN
- LC28 - Examination, inspection, maintenance and testing - Rating: AMBER
Key findings, inspector's opinions and reasons for judgement made
The inspection was undertaken on 6 and 7 May 2026 by the SNM site inspector and two human and organisation capability specialist inspectors. The inspection was also attended by a developing internal hazards specialist inspector.
The planned inspection targeted compliance against Licence Condition (LC) 6 (Documents, records, authorities and certificates), 24 (Operating instructions), 25 (Operational records) and 26 (Control and supervision of operations) specifically to RTW operations.
In addition, to the above announced LCs inspection, and in response to incident BN2605A0166, I sampled evidence of LC 28 (Examination, inspection, maintenance and testing) implementation of the safety mechanism required for the RTW operations.
The inspection involved a planning phase and a site visit, which included discussions with relevant Sellafield Limited personnel, review of records, sampling of information contained within electronic databases and other documentation, and a plant walkdown.
From a mixture of sampling records and discussions with Sellafield Limited personnel, I concluded the following:
No significant matters were identified that required immediate regulatory attention.
For LC6, I was satisfied with SNM's South implementation of the corporate arrangements for LC6. I provided regulatory advice relating to improvements of the local arrangements.
For LC24, I was satisfied with SNM's South implementation of the corporate arrangements for LC24 in relation to RTW Operator Instructions. I sampled completed Operator Instructions records for can transfers and these appeared in order.
For LC25, I was satisfied with SNM's South implementation of the corporate arrangements for LC25 in relation to RTW Operational records. I sampled records associated with completed can transfers and I was satisfied that, where appropriate, all requisite records have been adequately completed.
For LC26, I was satisfied with SNM's South implementation of the corporate arrangements for LC26 specific to RTW operations. I sampled the Control and Supervision Organisation Baseline and found that the document had completed its due process at properly constituted meetings of the local MSC. I sampled the certificates of assessment of those delivering control and supervision on the inspection dates and confirmed that those undertaking control and supervision activities have been appropriately competency assessed. I obtained confidence from the rostered duty DAP that all RTW operations are appropriately controlled and supervised. I also sampled the training record of the PCM coordinator and I found that the training record was in date.
For LC28, the examination, inspection, maintenance and testing of the neutron monitor (safety mechanism) has not been undertaken in a timely manner. I, therefore, am of the opinion that the required standard of compliance with the expectations of LC28 have not been met and I will seek improvement in this area.
Regulatory advice was also provided, as appropriate.
Conclusion
On the basis of the evidence sampled at the time of the inspection, I found that SNM South is compliant with the licensee’s corporate arrangements for LC6, 24, 25 and 26 specifically to RTW operations. I found, however, a shortfall against compliance with LC28, specifically to delivery of examination, inspection, maintenance and testing of the neutron monitor, which is designated as a safety mechanism in the safety case.
Taking all of the above into account, and noting the ONR guidance on inspection ratings, it is my opinion that, on balance, an inspection rating of Green (i.e. no formal action) for LC6, 24, 25 and 26, and an inspection rating of Amber for LC28 is merited here.
For the LC 28 Amber rating, I will raise an enforcement decision record to seek improvement in this area, see ENF-01059.