Executive summary
Date(s) of inspection
- December 2025
Aim of inspection
This was a readiness inspection for Active Handling Facility (AHF) for the activity of receiving fuel from the Wet Inlet Facility (WIF) storage pond in the Single Module Flask (SMF) for import into the Active Handling Facility via a Horizontal Posting Port (HPP) to enable Post Irradiation Examination (2025/28427).
In 2012 a fuel failure occurred at the Shore Test Facility (STF) which was located at the Nuclear Reactor Test Establishment (NRTE) Vulcan. It is necessary to undertake Post Irradiation Examination (PIE) of the STF fuel as well as fuel from other platforms to better understand the extent and cause of any failure mechanism(s).
PIE of naval fuel is neither new or novel within AHF, however, the import of failed naval fuel introduces new hazards, and therefore risks to the facility. The (G and H core) fuel is longer than the fuel currently received at AHF and the SMF cannot be accommodated in the existing import caves due to its physical dimensions.
The SMF will be received dry and posted horizontally into cave 6. A tent system has been installed to manage the potential contamination hazard with enhanced mobility due to electrostatic charge build up, known as fleas. The HPP and associated interlocks prevent operator exposure to the fuel as well as the contents of Cave 6.
Readiness for following activities was considered:
- Receipt of the SMF from WIF at the B12 east compound
- Removal of the SMF impact limiters using a telehandler (and fitting during export)
- Lifting the SMF from the road vehicle and placing it on the AHF air bogies (and loading (empty) during export)
- Movement of the SMF on the AHF air bogies from the B12 East garage to AHF Cave 6 HPP (and return of the flask during export (empty)
- De-lidding the SMF and docking the flask to the Cave 6 HPP
- Posting of the flask contents into Cave 6
- Undocking and re-lidding the SMF
The inspection followed assessments undertaken by Fault Studies, Control and Instrumentation, and Mechanical Engineering. The assessing inspectors satisfied themselves:
- that a reasonably conservative approach had been taken regarding radiological consequences and that safety measures had been designated accordingly;
- that the safety interlock systems associated with the HPP and the posting operation were suitable and sufficient;
- that there was adequate substantiation of the mechanical features associated with the HPP through sampling of the tie bar and tie bar brackets.
- that the SMF would retain bulk shielding if dropped during lifting activities in AHF
The high-level aim of the inspection was to confirm that the facility was suitably ready to commence active commissioning related to the receipt and posting of naval fuel (G and H core) into cave 6. The objective was to gather evidence and assurance that the operators and supervisors were ready to undertake the activities. The key focus areas were:
- Had been suitably trained and that the training programme and content was derived and delivered in line with relevant good practice;
- Regarding operation of the interlocks and measures that assure their personal safety from contamination or high-dose rate events.
- In relation to the local rules and contingency arrangements.
- Had suitable and sufficient operating instructions which were consistent with the claims on the operators from both the safety case and radiation risk assessment;
- Evidence that inactive commissioning had been appropriately undertaken and that learning had been incorporated in procedures and instructions.
Subject(s) of inspection
- IRR17 - Rating: GREEN
- LC 23 - Operating rules - Rating: GREEN
- LC 24 - Operating instructions - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
In our opinion, based on the evidence gathered during the course of the inspection:
- UKNNL demonstrated that they have derived and delivered a training programme which is consistent with relevant good practice.
- Supervisors and operators demonstrated suitable and sufficient knowledge and an understanding of the continuous-use instructions for the activities associated with the modified fuel route.
- UKNNL evidenced that the inactive commissioning programme and associated learning have been appropriately incorporated in the operating instructions and that there is sufficient awareness and testing of contingency arrangements.
Conclusion
In our opinion, based on the evidence gathered during the course of the inspection:
- UKNNL demonstrated that they have derived and delivered a training programme which is consistent with relevant good practice.
- Supervisors and operators demonstrated suitable and sufficient knowledge of the tasks and and understanding of the continuous-use instructions for the activities associated with HP110.
- There is evidence that the inactive commissioning programme and associated learning have been appropriately incorporated in the operating instructions and that there is sufficient awareness and testing of contingency arrangements.
- From a radiological protection perspective UKNNL have suitable arrangements in place for the transfer
In summary, in our opinion, UKNNL are ready to undertake the activities associated with HP110 - import of naval fuel to AHF.
No compliance gaps or issues were identified during the inspection, therefore, there are no associated regulatory issues. However, some observations and advice were provided to UKNNL.