Office for Nuclear Regulation

Sellafield Objective 3 - B6 Diffuser Demolition - Tower Crane Erection Readiness Review

Executive summary

Purpose of Intervention

SL has requested ONR’s agreement under its arrangements made under Licence Condition 22 [Modification or experiment on existing plant] for the erection of a tied tower crane to support demolition of the Pile 1 chimney diffuser.

I undertook an intervention at the Sellafield Site on 21 June 2018.  The purpose of the intervention was to provide evidence to support ONR’s judgement concerning SL’s readiness to commence erection of a tied tower crane to support demolition of the Pile 1 chimney diffuser prior to issue of a licence instrument to permit that activity.

Interventions Carried Out by ONR

SL provided an overview of project readiness and progress with its hazardous activity readiness review.  ONR specialist inspectors engaged with SL staff and contractors on the following topic areas:

ONR’s inspectors visited the construction site to inspect the tower crane tie installation and control and supervision of operations in the construction compound.

Explanation of Judgement if Safety System Not Judged to be Adequate


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

I am satisfied that SL has considered learning from experience in the development their emergency arrangements for the tower crane and ONR confirmed that these emergency arrangements have been successfully demonstrated.  ONR has also confirmed that the human based safety claims have been incorporated into working level arrangements and through interviews with various working parties ONR confirmed that these were understood.  In addition, I consider that SL’s approach to examination, inspection, maintenance and testing of the tower crane is consistent with relevant good practice.

This readiness inspection identified several areas that remain outstanding but which SL has plans in place to complete prior to tower crane erection.  This includes completing site-specific training for contractor staff who are not due to be on site until early July.  This outstanding work is regarded by ONR as achievable within the remaining time, and through previous interventions ONR has confidence that these will be completed appropriately.  These have been identified as category A findings by SL’s Nuclear Inspection and Oversight (NIO) function.  I observed SL’s NIO function completing a robust hazardous activity readiness review process and have taken confidence from completion of that process and SL’s commitment not to commence tower crane erection until these category A findings have been completed.

Conclusion of Intervention

I am satisfied with the governance arrangements in place to secure closure of SL’s category A findings which is a constructive approach to enable ONR to permit tower crane erection and so achieve effective delivery against a clear and prioritised safety and security outcome.  The majority of the enabling activities have been completed, the remaining actions are regarded as routine business and I am satisfied that an inspection rating of GREEN is merited.