Office for Nuclear Regulation

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Sellafield Inspection of Design Arrangements in Decommissioning

Executive summary

Purpose of intervention

This intervention was undertaken at the Sellafield Limited (SL) Design Offices in Risley, Warrington.

Inspection of Licence Condition (LC) compliance at nuclear licensed sites is an important aspect of ONR’s activities. ONR has defined a programme of system inspections and LC compliance inspections, which focus on the aspects of SL’s operations that are most important to safety and legal compliance. This LC17 (Management Systems) inspection is identified in ONR’s PP3 inspection plan which covers SL’s Decommissioning Division.

LC17 was selected for inspection as a number of recent new build programmes for Decommissioning have experienced delays and functional / quality issues related to design.

Interventions Carried Out by ONR

I carried out an inspection of SL’s arrangements for Design Governance in the Decommissioning Division. LC17 requires the licensee to establish and implement management systems which give due priority to safety. LC17 also requires that these management systems include adequate quality management arrangements in respect of all matters which may affect safety. This inspection was carried out in accordance with ONR’s inspection guidance for LC17 as defined in NS-INSP-GD-017, taking additional guidance from ONR guides TAST-GD-057 (Design Safety Assurance), TAST-GD-049 (Design Authority Capability) and TAST-GD-077 (Procurement of Nuclear Safety Related Items or Services).

My inspection focussed on the management arrangements for design activities in Sellafield Decommissioning, particularly examining how SL ensures timely, fit for purpose designs, which can be constructed and operated safely to deliver its decommissioning mission.

The inspection was carried out through office-based examination of procedures and records and interviews with staff. The intervention was undertaken by the Site Inspector supported by an ONR Leadership and Management for Safety specialist inspector.

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A – This was not a Safety Systems inspection.

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

I judged that the licensee has established and implemented management systems for Design which give due priority to safety. No significant non-compliances were noted against the Licence Conditions, but some areas for improvement were identified when compared against ONR assessment guidance.  In addition, some examples of good practice were noted.

The organisational structures of the projects inspected were shown to be compliant with the model defined in SL’s Design Authority and Intelligent Customer Charter. I reviewed the arrangements and identified that some of the lower level procedures were however, not consistent with the Charter and require updating to reflect the current organisation structures.

I identified an issue where design requirements appeared to have been redefined throughout the project documentation to become unnecessary constraints. In some cases this was because the plant functional requirement had been inappropriately redefined, but in other cases current limitations in other plants had been read-across as a design requirement for related plants. This has the potential to introduce unnecessary functional limitations or complexity into the design of these plants. SL accepted this and agreed to review its arrangements for requirements definition and flowdown. 

I identified that the SL process for Design Reviews does not require a chair to be independent of the project, and in many cases the Design Reviews are chaired by the project’s Project Engineering Manager. I challenged that this did not provide adequate independence and does not meet relevant good practice for reviews as defined in the British Standard (BS61160). SL agreed to review the requirement for an independent chair in their arrangements.

The Responsibilities and Accountabilities were reviewed, and these highlighted the importance of the Project Engineering Manager, who is the most senior engineer dedicated to each project.

Evidence of good challenge for balancing technical benefits against programme delivery opportunities was demonstrated on the Silos Direct Encapsulation Plant (SDP), where options for reducing commissioning tasks were being reviewed. I judged the output to be a reasonable example of conservative decision making.

Based on the evidence of this inspection, there appeared to be a lack of Design Authority involvement in the design programme. I suggested SL should review the expectations for the Design Authority as described in ONR guidance (TAST-GD-079, and TAST-057). 

I reviewed risk registers for a number of programmes and these appeared to be adequately maintained, and included technical risks as well as programme risks.

During the inspection I asked how ‘Security By Design’ aspects are included in SL’s programmes, and was satisfied that each programme I reviewed demonstrated an adequate appreciation of security aspects and had identified a clearly accountable person to take the lead for security aspects.

Conclusion of Intervention

I judged the licensee’s compliance with LC17 to be adequate; the licensee has established adequate arrangements for design which give due priority to safety, and demonstrated consistent implementation on these projects. Although two issues were noted, these do not represent an immediate safety concern and the licensee was proactive in accepting these issues and agreed to review and improve thepse aspects of its arrangements. These matters will be followed up the site inspector as part of routine regulatory interactions.