Office for Nuclear Regulation

This website uses non-intrusive cookies to improve your user experience. You can visit our cookie privacy page for more information.

Control of Radiation Exposure (CORE) Inspection

Executive summary

Purpose of intervention

In line with an Office for Nuclear Regulation (ONR) planned intervention, to look at Control of Radiation Exposure (CORE) across all licensee sites, I and another ONR Radiological Protection (RP) specialist (referred to as we in this report) conducted an inspection of the control of radiation exposure during operations conducted by Urenco UK Ltd at their Capenhurst site.  Our inspection also included operations conducted by Capenhurst Nuclear Services - CNS (a UUK Ltd tenant on the Capenhurst Nuclear Licensed site), allowing us to make direct comparisons with the systems employed by both UUK Ltd and CNS to control operator radiation exposure.

Interventions Carried Out by ONR

This ONR intervention was conducted under Regulation 8 of the Ionising Radiations Regulations (IRRs) 1999.  To ensure consistency with previous ONR CORE inspections, the inspection was conducted using a standard questionnaire and follow up face-to-face question and answer session with key UUK Ltd representatives and representatives of CNS at the UUK Ltd’s Nuclear Licensed Site at Capenhurst.

During the intervention we took the opportunity to view the application of UUK Ltd’s and CNS’s arrangements for the control of radiation exposure, by visiting a number of process plants and some of the storage areas (Rafts) associated with these, as well as some of the CNS waste/residue storage areas.  We also took the opportunity to view CNS’s control of worker radiation doses in the context of known high dose operations i.e. during asbestos stripping (in a high background dose rate area) and during cylinder inspections (involving workers being in close proximity to large arrays of the cylinders, for significant periods of time, which have greater than background dose rate fields associated with them).

Explanation of Judgement if Safety System Not Judged to be Adequate

No safety systems inspection was undertaken during this intervention and hence this section is not applicable.

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

An extensive visit to a key UUK Ltd process plant, Uranium Hexafluoride (Hex) cylinder storage areas owned and operated by both UUK Ltd and CNS (termed “Rafts by both UUK Ltd and CNS), CNS high dose projects and a large CNS waste/residue storage facility, revealed generally good standards of dose and contamination control.  All staff interviewed were knowledgeable and enthusiastic about their work and there was, in our opinion, ample evidence of staff and management working closely together on initiatives to further reduce worker doses and contamination events.

One area of fenced off contaminated land fenced (the East Side Curtilage) was seen to be in a poorer condition than the rest of the Capenhurst site as a whole, but the ONR site inspector and the Environment Agency (EA) are already closely overseeing a CNS project (due to commence in 2016) to substantially remediate this land to facilitate the construction of another Raft.  We were content with this position.

During this part of the inspection we offered some advice to UUK Ltd about reconsidering the designation of “Process Areas” within the main enrichment process facility we visited (since this description lies outside the IRRs 1999 and has, in our opinion, a potential to cause confusion regarding potential radiological conditions).  It was also our view that control of inadvertent access to some of the Rafts (designated as “Controlled Areas Radiation” under IRR 1999) could be improved and that the arrangements to protect Rafts 11 and 12, effectively established relevant good practice on the site.  UUK Ltd readily agreed to consider our advice in both areas.

We held discussions with both UUK Ltd and CNS staff, regarding the evidence presented in response to the questionnaire forwarded by ONR in advance of the inspection.  In our opinion the evidence sets from both UUK Ltd and CNS were comprehensive and detailed.  In addition both companies gave robust and well underpinned answers to questions we raised around this evidence.  Additional documents were provided promptly and UUK Ltd facilitated access to a number of computer databases it uses to collate and interrogate data relating to radiological safety performance.

All information provided was of a good standard and the areas for improvement where we provided advice to UUK Ltd and CNS, were in our opinion, of a relatively minor safety significance.

Conclusion of Intervention

From our discussions with the staff who accompanied our inspection and additional conversations with the staff we encountered on the site during our inspections, we obtained a positive impression of radiological safety culture across both UUK Ltd and CNS.  Our observations in the main UUK Ltd process facility demonstrated marked improvements since an ONR” Improvement Notice” (issued against IRR 1999) some years earlier.  We also observed good radiological control across a wide cross-section of facilities, operated by both UUK Ltd and CNS.  Both UUK Ltd and CNS also presented strong documentary evidence against the questionnaire for the CORE inspection, issued to both UUK Ltd and CNS in advance of the inspection. 

A discussion was held with a cross-section of UUK Ltd and CNS Safety Representatives, which also presented a positive picture as to how seriously management from both CNS and UUK Ltd treat radiological safety.  No issues requiring regulatory attention were raised by the Safety Representatives.

In response to all of the regulatory advice we provided, to both UUK Ltd and CNS, we readily obtained commitments to give further detailed consideration to the points made. 

No matters of regulatory concern requiring further regulatory action were identified from our inspection.

From the totality of evidence we sampled, we consider that the inspection merits a marking of 2 i.e. “Good Standard.”