Office for Nuclear Regulation

Dounreay Prototype Fast Reactor Sodium Tank Farm Licence Condition 22 Inspection

Executive summary

Purpose of intervention

I carried out a planned compliance inspection as part of the Dounreay integrated intervention strategy (IIS).  The inspection will serve to inform ONR’s position on the commencement of work to seal tanks 3 and 4 (which were affected by the 2014 fire) at the prototype fast reactor (PFR) tank farm.

Interventions Carried Out by ONR

I carried out an inspection against licence condition (LC) 22 (modification or experiment on existing plant) of the modification proposal to seal tanks 3 and 4.

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A

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

Overall I consider compliance with LC 22 as it relates to the implementation of this modification to be good.  In particular, I consider there to have been good operator involvement in the planning of the modification, with the result that there is a consistent understanding of the work involved among senior management, supervisors and the workface.

Furthermore, I consider that the work has been adequately assessed with regard to risk and hazard, is being managed well and will finish with the tanks in a safer, sealed state.  I therefore consider that ONR should not object to the licensee carrying out the work specified to seal tanks 3 and 4, although any subsequent work to clean the tanks should be subject to separate consideration.

Conclusion of Intervention

I found no issues that significantly affect safety, that require enforcement action or that require amendments to the Dounreay IIS.