Office for Nuclear Regulation

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Readiness Review in advance of restart of Fissile Operations

Executive summary

Purpose of Intervention

Following a number of events across the Nuclear Fuel Production Plant (NFPP), Rolls Royce Submarine Limited (RRSL) took the conservative decision to suspend operations.  The site took the opportunity to review arrangements for the safe control and supervision of fissile activities.  This intervention  was undertaken in order to provide assurance  that the risk of recurrence is a low as reasonably practical prior to the resumption of these activities.

Interventions Carried Out by ONR

The intervention consisted of an inspection in relation to RRSL’s arrangements for criticality control, control and supervision of work in NFPP Contact Facilities.  It also included an on-plant demonstration of RRSL’s revised arrangements for fissile activities in the NFPP Chemical Plant.  The inspection sought to confirm that the licensee has made the necessary improvements to demonstrate that adequate arrangements are in place for the safe control of fissile operations. 

The inspection involved a focused readiness inspection informed by ONR’s expectations of Licence Condition (LC) 10 (Training), LC23 (Operating rules), LC24 (Operating instructions) and LC26 (Control and supervision of operations) as they are applied to fissile operations in NFPP. The inspection was undertaken by the ONR Nominated Site Inspector, supported by 3 specialist inspectors.  It involved examination of relevant licensee documentation and targeted discussions with relevant members of the licensee’s staff.  The scope of inspection was derived from relevant ONR Technical Inspection Guides (NS-INSP-GD-010 Revision 1, Revision 5, NS-INSP-GD-023 Revision 5, NS-INSP-GD-024 Revision 4, and NS-INSP-GD-026 Revision 3).

Key Findings, Inspector's Opinions and Reasons for Judgements Made

Using the inspection guidance, the ONR inspection team undertook a deep slice sample of the revised arrangements that have been implemented by RRSL.  This targeted  the planning, organisation, control and supervision of fissile operations in the chemical plant including the movement control of special nuclear materials.

The inspection team concluded that RRSL has resolved the shortfalls against relevant good practice that contributed to previous events and made the necessary enhancements to enable the restart of fissile operations in a safe and controlled manner.

Conclusion of Intervention

On the basis of the information provided and sample evidence obtained during this intervention, I concluded that the licensee has made the necessary enhancements to demonstrate that adequate arrangements are in place for the safe control of fissile operations.

There are no regulatory issues to address before site releases their own internal Hold Point to begin the restart of fissile operations in the NFPP Contact Facilities; however two regulatory issues were raised to enable ONR to follow up on two minor regulatory matters.