Office for Nuclear Regulation

Urenco UK Ltd - Systems Based Inspection

Executive summary

Purpose of Intervention

This Systems Based Inspection (SBI) was carried out as part of ONR’s permissioning strategy for the Tails Management Facility (TMF) at the URENCO UK Ltd licensed nuclear site at Capenhurst.

Interventions Carried Out by ONR

The by-product of uranium enrichment is depleted uranium hexafluoride, known as tails.  A new facility, the Tails Management Facility (TMF), is being constructed on the URENCO UK Ltd’s Capenhurst site to convert tails to an oxide of uranium, a chemical form more suitable for long-term storage.  The TMF is being constructed by, and will be operated by, Urenco ChemPlants Ltd (UCP), a tenant on the Capenhurst site, but owned by the parent company URENCO.

This inspection was carried out to determine the adequacy of implementation of the tenant’s safety case claims in respect of the Tails De-conversion Plant (TDP), and is part of an ongoing programme of inspections and assessment of UCP’s readiness to commence active commissioning of the TDP, which is subject to an ONR regulatory hold-point.  ONR examined evidence to determine compliance against six key Licence Conditions (LCs).  These LCs were selected in view of their importance to nuclear safety and in providing a structured approach to determining whether the safety case has been implemented adequately through the system being inspected.

ONR assessed compliance against the following LCs using applicable inspection guidance:

The inspection examined the applicable safety case claims, through a combination of document reviews, discussions with plant operators, internal nuclear assurance and plant inspections to determine compliance against the selected LCs.

The focus of this inspection was to ascertain whether the licensee’s and tenant’s licence condition arrangements would deliver nuclear safety when implemented and to ascertain whether further inspection may be required prior to giving regulatory permission to commence active commissioning of the TDP.

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

From the areas targeted and the evidence examined during the SBI, ONR considers that UCP is adequately implementing those safety case claims that relate to the Tails De-conversion Plant, or was able to demonstrate that implementation will be adequate once finalised (the TDP has yet to complete commissioning). 

Some minor observations were made during the inspection for the licensee and the tenant to consider.

Conclusion of Intervention

From the evidence sampled during this SBI, it was judged that there were no matters that have the potential to impact adversely on nuclear safety. Consequently, the inspection findings were shared and accepted by UUK and UCP as part of normal inspection feedback. ONR considers UCP adequately demonstrated ownership and implementation of the TDP safety case to ensure and maintain nuclear safety.

ONR’s conclusion from the findings of the inspection is that the implementation of the TDP safety case is adequate so far.  However further inspection will be required as part of the planned ONR readiness review for the commencement of active commissioning of the TMF.