Executive summary
Date(s) of inspection:
- January 2025
Aim of inspection
ONR nuclear safeguards inspectors conducted an Accountancy and Control Plan (ACP) compliance inspection of the Sellafield Ltd. THORP UO3 Drum Store (QS32) and THORP Product Finishing Line 6 (QS33) on 28 and 29 January 2025. The purpose of this inspection was to seek evidence in support of Sellafield Ltd.’s compliance with The Nuclear Safeguards (EU Exit) Regulations 2019 (NSR19).
These MBAs have been targeted for the following reasons:
- Finishing Line 6 (QS33) has recently completed final accountancy washouts of QNM from the plant’s liquor tanks, and is now transitioning operations towards routine POCO activities. This inspection will enable ONR to target accountancy and operating records for the recent washouts, and gain assurance that appropriate arrangements for POCO activities are in place at the MBA.
- Within THORP UO3 Drum Store (QS32), exports from this MBA must be remeasured upon export due to a known discrepancy between book and physical inventories. Although the THORP UO3 Store has recently unpacked a planned UO3 shipment and returned this to store, future shipments of QNM may take place which will require this remeasurement. The MBA has also received a set of QNM sample archives from MBA QS31 (THORP) in September 2024. The inspection will enable ONR to target accountancy and operating records for the recent sample transfers, and gain assurance that appropriate arrangements for the measurement of QNM prior to export are in place at the MBA.
Subject(s) of inspection
- FSE 4 Reporting, Anomalies, and Investigations - Rating: GREEN
- FSE 6 Measurement Programme and Control - Rating: GREEN
- FSE 7 Nuclear Material Tracking - Rating: GREEN
- FSE 8 Data Processing and Control - Rating: GREEN
- FSE 9 Material Balance - Rating: GREEN
- NSR19 Reg03 - Declaration of basic technical characteristics - Rating: GREEN
- NSR19 Reg06 - Accountancy and control of qualifying nuclear material - Rating: GREEN
- NSR19 Reg09 - Operation of an accountancy and control plan - Rating: GREEN
- NSR19 Reg10 - Operating records - Rating: GREEN
- NSR19 Reg11 - Accounting records - Rating: GREEN
- NSR19 Reg12 - Accounting reports - Rating: GREEN
- NSR19 Reg20 - Weight units and categories of qualifying nuclear materials - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
The inspection comprised of discussions with Sellafield Ltd staff, sampling and review of Sellafield Ltd operating, accounting records and other source documentation, and plant walkdowns to check the implementation of arrangements. It was carried out in line with the ONR Safeguards Technical Inspection Guide (TIG) and the ONR Nuclear Material Accountancy, Control and Safeguards Assessment Principles (ONMACS) which can be found on ONR’s website (onr.org.uk).
Based on the sampled evidence I judge that Sellafield Ltd. is implementing appropriate and proportionate arrangements for nuclear material accountancy at QS32 and QS33 and have met the requirements of Regulations 3, 6 (1-4) , 9, 10 (1) , 11(1-4), 12, 20 of NSR19 and ONMACSs FSEs 4, 6, 7, 8 and 9.
I made one Safeguards Observation relating to minor updates use of check weights during the calibration of one weigh balance within Material Balance Area (MBA) QS33.
I provided one piece of Regulatory Advice regarding capturing incremental additions to residue cans during POCO activities through the use of source documentation appended to an existing instruction.
Noting ONR guidance on inspection ratings, I judge that a GREEN rating for this inspection is suitable.
Conclusion
In line with the ONR Inspection Rating Guide, based on the sampled evidence during the course of the intervention at Sellafield Ltd, I consider a rating of GREEN against the following as identified within the scope of inspection:
THORP U03 Store (MBA QS32); NSR19 Regulations 6 (1-4) , 9, 10 (1) , 11(1-4), 12, 20 and ONMACS FSE 6, 7, 8 and 9
THORP Finishing Line 6 (MBA QS33); NSR19 Regulations 3, 6 (1-4) , 9, 10 (1) , 11(1-4), 12, 20 and ONMACS FSE 4, 6, 7, 8 and 9