Executive summary
Date(s) of inspection
- April 2026
Aim of inspection
In support of ONR’s work to release the regulatory hold-point for Phase 1 of the Low Enriched Uranium Plus (LEU+) Project (PR-01643), this inspection is being undertaken to examine Urenco UK Ltd.’s (UUK) approach to implementing the necessary modifications for, and readiness to undertake, uranium enrichment operations beyond 6 wt.% U-235, as proof of concept for the LEU+ Project.
Subject(s) of inspection
- LC10 - Training - Rating: Green
- LC22 - Modification or experiment on existing plant - Rating: Green
- LC24 - Operating instructions - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
In response to demand from the nuclear fuel marketplace, UUK are intending to implement a modification to enrich U-235 up to 7.5%, which is a higher concentration than the 5% enriched U-235 currently produced by the dutyholder. In Phase 1 of the LEU+ project UUK will trial enriching U-235 to 7% with a 0.5% safety margin.
We completed a readiness inspection ahead of this trial focussing on ‘people’ and ‘process’, making judgements against Licence Conditions (LCs) 10 – Training, LC 22 – Modification or Experiment on Existing Plant, and LC 24 – Operating Instructions.
We targeted modifications made to the safety cases for E23 Enrichment Plant and Chemistry Services (Building 240), progress with safety case adoption activities, as per UUK Safety Case Assessment and Management Procedure (SCAMP) 930: Adoption of Safety Cases, and we examined UUK’s preparation for commissioning tests and plans for filling the LEU+ demonstration cylinder.
For LC 10, we noted that there are potential gaps in the training development process and that there is no evidence of formal competence assurance. However, given the relatively limited nature of the changes, and evidence that the changes and their implications have been understood widely within the facility, we considered the implemented arrangements to be acceptable.
For LC 22, we noted shortfalls regarding the OCC updates and requested UUK include an action in the forward action plan to complete these. Otherwise, we considered the updates for LEU+ have been adequately controlled.
For LC 24, we recognised that considerable effort has been made to update the Operating Instructions. Although further minor improvements could be made, they appear fit-for-purpose for this permission and are well understood by the relevant staff.
We considered that a Green inspection rating is appropriate for each of these LCs.
Conclusion
Based on our sample, we consider that UUK is ready to complete the LEU+ proof of concept trial.
For the scope of this readiness inspection we consider for LCs 10, 22 and 24 a Green rating is appropriate against ONR’s inspection rating guide.