Office for Nuclear Regulation

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Intervention at URENCO UK Limited

Executive summary

Purpose of intervention

    The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with URENCO UK Limited (UUK) at the Capenhurst site against intervention strategies defined by ONR Programmes. This was a combined intervention, conducted over three days, in accordance with the strategic plans of the Cross ONR and the Sellafield, Decommissioning, Fuel and Waste Programmes.

This Intervention was undertaken to review and verify the adequacy of the actions of UUK arising from the findings of the ONR investigation into the 11kV underground cable strike that occurred at UUK’s Capenhurst site on 18 September 2013, focussing on setting to work arrangements.

ONR also carried out a planned compliance inspection of Licence Condition 26 (LC 26); the purpose of this Condition is to ensure that all safety related operations are only carried out under the control and supervision of suitably qualified and experienced personnel, and refers to all operations as defined in Licence Condition 1. The LC 26 focus of this intervention was to review the posts and persons appointed to control and supervise operations associated with new setting to work and permit to work systems of working.

The UUK 11kV underground cable strike reported dangerous occurrence was fully investigated by ONR and resulted in enforcement action by way of letter. An investigation outcome was the planned ONR delivery of this Corporate Intervention to establish regulatory confidence that priority action had been taken by the Licensee to prevent a recurrence of the event via its procedures for setting people to work, and particularly permit to work arrangements.

Interventions Carried Out by ONR

The key regulatory activities undertaken during the Intervention were planned to review the effectiveness of UUK arrangements for risk assessment of high hazard operational and maintenance activities, with associated competently resourced control procedures.

Areas of focus included consideration of the following aspects associated with setting to work.

ONR explored the roles of those with responsibilities and sought detail of their training and experience; witnessed a suite of safe system of work meetings; observed a range of UUK setting to work arrangements in process; witnessed authorised work in process; sought feedback from appointed Health and Safety Representatives and via interviews with staff at all levels, ranging from maintenance engineers through to the Chief Nuclear Officer; and reviewed the role of contractors in setting to work arrangements and their interface with UUK personnel. UUK and CNS documentation was referenced in advance of and during the Intervention. In consequence the Intervention enabled an insight into a number of aspects associated with the assessment of risk, including work control and setting to work arrangements in practice.  

The inspection provided an opportunity to verify action taken (and continuing to be taken) by UUK following the 11kV cable strike incident, and to explore the wider issues around a more recent DRUPS electric arc incident with setting to work relevance of 12 August 2016 which resulted in a contractor sustaining burns to his hands, arms and face.

Regulatory judgement was based on determining compliance with sections 2 and 3 of the Health and Safety at Work etc. Act 1974 and relevant statutory provisions made under the Act. A number of key relevant statutory provisions were referred to during the site visits, including the Management of Health and Safety at Work Regulations 1999; the Control of Asbestos Regulations 2012; the Electricity at Work Regulations 1989; the Work at Height Regulations 2005 (as amended); the Control of Substances Hazardous to Health Regulations 2002 (as amended); and the Construction (Design and Management) Regulations 2015.

Explanation of Judgement if Safety System Not Judged to be Adequate


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

The ONR inspection team were fully and consistently in agreement in regard to their shared Intervention findings.

UUK have reviewed their setting to work processes as a key output of the investigation into the 11kV cable strike incident of 18 September 2013. UUK in their opening presentation to ONR accepted the root cause of this event was ‘an acceptance of risk without an adequate understanding or control of the potential hazard’.

A number of areas of good practice associated with the development of the UUK Safe System of Work Manual (Document Reference: UUK-SSOW-MAN-01) were seen during the Intervention, reflecting the considerable efforts of UUK personnel in the development and initial implementation of this ‘controlled approach to planning and managing the risks associated with preparing and performing maintenance, modification and construction project work’. Individual UUK staff expressed positive views of the new approach as a significant improvement on former setting to work arrangements: ONR recognised improved documentation and accountability benefits. ONR witnessed a suite of meetings associated with work planning and coordination, and recognised the potential value of this approach for work integration management and oversight and, with further development, risk management.

ONR were, however, disappointed and concerned at the lack of timeliness in the follow up to the 11kV cable strike event, as demonstrated by the delayed and as yet incomplete implementation of UUK’s revised arrangements for setting people to work.

ONR question the suitability of the revised management arrangements when undertaking permitted activities. Standards and expectations in regard to risk based supervision and monitoring should be explicitly stated in relevant documentation.

The lack of control and supervision identified in the more recent DRUPS incident review reflected similarities with the circumstances surrounding the 11kV cable strike.

The capabilities required to fulfil UUK Manual Safe System of Work roles and responsibilities need to be fully explored, associated competencies identified and training requirements confirmed and appropriately resourced. ONR reference, for example, those with functional accountabilities and responsibilities relevant to key setting to work activities.

ONR’s review of setting to work arrangements encompassed a number of core conventional health and safety standards, for example the management of asbestos. The apparent lack of asbestos awareness training amongst, for example, plant maintenance personnel, and restricted access to the site register of asbestos containing materials were matters of concern which merit further, more detailed exploration by ONR.

Conclusion of Intervention

Control and supervision – LC 26 and conventional health and safety findings

Inconsistent and incomplete action has been taken by UUK to address the priority topics as confirmed to UUK by ONR in letters issued during and at the conclusion of the ONR investigation of the 11kV cable strike, specifically to ensure that suitable control measures are in place to prevent a recurrence.

The existing ONR Issue which formally records the UUK action required and which included ONR verification of the adequacy of actions taken (by this Intervention) will be closed as the technical review of UUK’s response has been satisfied by the Inspection Intervention, although not all actions have been delivered.

Overall ONR’s regulatory confidence with regard to Control and Supervision is diminished: based on the evidence provided during the Intervention ONR deems the compliance with LC 26 currently to be significantly below standard and as such demand immediate improvement as outlined below.

UUK’s response to ONR’s required improvements will be closely monitored.

A new ONR Issue is proposed at Level 2 (subject to ONR governance procedures), to reflect the lack of UUK commitment (pre Intervention) to full delivery of specified actions, the relative immaturity of the current approach, and the associated regulatory omissions identified by ONR, for example in regard to competence for role delivery, contractor oversight, emerging management of asbestos issues. The new ONR Issue, to be confirmed to UUK by a strongly worded enforcement letter, will incorporate outstanding elements of the earlier Issue and will reference the following.

The management of asbestos

Matters of evident concern were identified in regard to the arrangements for the management of asbestos on the Capenhurst site, prompting UUK’s voluntary cessation of site excavation work upon potentially asbestos containing material being revealed with insufficient associated asbestos control measures. As a direct consequence of the unacceptable working arrangements encountered an early return visit to site is being arranged to undertake an Asbestos Management Intervention. The Intervention will review the nature and extent of UUK’s asbestos management arrangements.