Executive summary
Date(s) of inspection:
October 2025
Aim of inspection
ONR sought to draw an independent and informed regulatory judgement that the Physical Inventory Taking (PIT) arrangements at Urenco ChemPlants (UCP) are sufficient to meet regulatory expectations, to gain confidence in the Inventory difference and associated action level declared for the facility.
Inspection goals included:
- Verification of procedural compliance and procedure suitability.
- Identification of any shortfalls in the IDAL derivation based on plant observations.
- Gain independent confidence into the accuracy and suitability of the UCP PIT declaration.
Subject(s) of inspection
- FSE 9 Material Balance - Rating: Green
- NSR19 Reg15 - Material balance report and physical inventory listing - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
ONR carried out a Physical Inventory Taking (PIT) evaluation at Urenco Chemical Plants (UCP); focusing on The Nuclear Safeguards Regulations 2019 (NSR19) Regulation 15 and ONR Nuclear Material Accountancy, Control and Safeguards Assessment Principles (ONMACS) Fundamental Safeguards Expectation (FSE) 9: Material Balance; both were rated green. This was a reactive inspection based on the Material Unaccounted for (MUF) exceeded the inventory difference action level at the Feb-25 PIT, and Urenco planning an interim-PIT during a plant outage, which gave ONR an opportunity to inspect how Urenco carry out the PIT at UCP and gain confidence in their PIT results.
The inspection primarily consisted of task based observations of the on plant and office based activities undertaken as part of the PIT. As well as interviews with key members of staff, such as the Uranium Accountancy manager and Nuclear Material Custodian.
This intervention was performed in line with ONR's guidance as described in the relevant technical inspection and assessment guides, which can be found on ONR’s website (onr.org.uk).
During the inspection three minor shortfalls against the regulations were identified, for which two Regulatory Issues were raised. Eight items of regulatory advice were provided on how to improve the PIT, and two items were provided to independent assurance for potential follow up.
A number of items of good practice were identified, including the displayed NMACS culture of the PIT team, and the robustness of their anomalies investigations undertaken during the PIT.
The PIT arrangements were judged to be proportionate to both the safety of facility personnel and the facility described in the Basic Technical Characteristics declaration. The identified shortfalls were not judged to significantly challenges to the conclusions from the UCP PIT.
Conclusion
Based on the sample inspected, I judge that Urenco ChemPlants are adequately implementing procedures and are producing adequate operator records, accountancy records, and accountancy reports as part of a PIT. The implementation of these arrangements is supporting the accountancy and control of QNM in-line with regulatory expectations FSE9 and are compliant with regulations 15 and schedule 2 of NSR19.
Two regulatory issues have been raised to address minor shortfalls.
Upon consideration of the ONR guidance on inspection ratings, I judge that a rating of GREEN (no formal action) is appropriate.