- Site: Urenco UK Ltd
- IR number: 21-122
- Date: November 2021
- LC numbers: 8, 10, 12, 24, 28, 36
Executive summary
Purpose of Intervention
This inspection was undertaken as one of a series of planned cross-site criticality inspections across a number of GB licensed nuclear sites and focussed on the implementation of arrangements to manage criticality safety. It had three main aims:
- To examine the adequacy in the licensee’s management of criticality safety and to ensure rectification of any identified shortfalls;
- To identify areas of good practice across the licensees inspected and to share these across the UK nuclear industry; and
- To seek improvements in licensee’s management of criticality safety and to highlight and action areas where ONR’s own guidance may be improved.
To provide a consistent approach across each of the individual criticality inspections, it was deemed appropriate to conduct the inspection against a number of Licence Conditions (LCs) which were judged to have direct relevance to criticality safety, i.e. LC 8 “Warning Notices”, LC 10 – “Training”, LC 12 - “Duly Authorised and Other Suitably Qualified and Experienced Persons (DAP/SQEP)”, LC 23 – “Operating Rules”, LC 24 –“Operating Instructions”, LC 28 – “Examination, Inspection, Maintenance and Testing” (EMIT) and LC 36 – “Organisational Capability”.
Interventions Carried Out by ONR
The inspection was conducted through a walk-down of one of the UUK enrichment plants, by discussions with key plant personnel and by examining the licensee’s criticality safety documentation, training records, maintenance schedules / records and on-site signage (e.g. criticality notices).
Explanation of Judgement if Safety System Not Judged to be Adequate
Not applicable.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
The key findings against each LC are recorded below.
We were satisfied with the licensee’s arrangements for warning notices.
UUK’s arrangements for ensuring its operators are adequately trained were demonstrated to ONR. Some observations were made by the inspectors which UUK noted, however we were satisfied with the licensee’s arrangements for criticality safety training.
Throughout the inspection, ONR found that UUK had a satisfactory means for ensuring the adequacy of its operating rules and instructions, with clear involvement of operations teams in ensuring the usability of such instructions. UUK had also posted the OCC at the entrance/exit of the facility allowing for quick reference by the plant operators.
There were some good examples of engineering that helped reinforce operational safety requirements that rely on human agency, e.g. dedicated trolleys for storage of items (pumps, traps etc.) which ensure safe separation, painted floor areas detailing where trolleys should be placed and the use of detachable trolley handles which are limited in number in the entire plant preventing multiple trolleys being moved at any one time.
ONR sampled maintenance arrangements which had been conducted by UUK’s maintenance team and maintenance contractors for various items seen in operation during the plant walkdown including the facility Criticality Incident Detection and Alarm System (CIDAS), the Weigh Scales and Contaminated Pump-set Trolley.
From our overall sample, we judged that there is a clear and structured approach to EIMT and we were satisfied with UUKs arrangements against LC 28 as they relate to criticality safety.
UUK and ONR discussed the ongoing recruitment issue facing UUK with regards to its Site Criticality Assessor roles. UUK is currently advertising vacancies for these positions, however, despite competitive salary offers and additional incentives, they are unable to recruit anybody on a permanent staff basis. The assessment team is presently being bolstered by contractors, who currently operate on a one-month notice period. UUK noted the following further actions it has taken to manage this situation and mitigate the risks and other compensatory arguments.
Overall, it was considered that UUK have taken reasonable steps to ensure the availability of SQEP criticality safety resource which is hampered by an industry-wide shortage of criticality assessors. There was nothing identified during this inspection which pointed to a lack of adequate criticality safety resource.
The inspectors requested that UUK issue a formal response to the RI, asking they give mention to the steps taken and the problems they have had resolving it.
Conclusion of Intervention
This criticality inspection focussed on criticality aspects of LCs 8, 10, 12, 23, 24, 28 and 36. Overall, we judged UUK’s arrangements to be adequate, with no significant areas of concern.
Instances of Good Practice were also observed and recorded by the inspectors.
Some minor gaps to UK relevant good practice in respect of criticality were observed and these were drawn to the attention of the licensee who agreed to consider them.