Office for Nuclear Regulation

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Sellafield - THORP - TOS (Thorp Operational Services) - Routine licence compliance inspection covering Licence Conditions 23, 24 and 26

Executive summary

Purpose of intervention

The purpose of this intervention was for the Office for Nuclear Regulation (ONR) to undertake a routine Licence Condition (LC) compliance inspection to assess Sellafield Ltd's (SLs) compliance with the following LCs within the Thorp Operations Services (TOS) unit, part of the Thermal Oxide Reprocessing Plant (THORP):

Interventions Carried Out by ONR

ONR carried out a one day team inspection comprising of several ONR specialist inspectors.

Explanation of Judgement if Safety System Not Judged to be Adequate


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

A review of the operating rules within TOS identified that they generally met ONR guidance and there was good evidence of their implementation via supporting documentation.

The number of differing operating instruction types and names resulted in the understanding of the relative status of these operating rules being unclear to the personnel responsible for their application.

Expectations for the use of procedures within TOS appeared either unclear or not fully met.

Although there was adequate evidence of control and supervision of operations within TOS, the visibility of the line of sight from the implementation on plant to the licence condition was unclear to THORP personnel.

Conclusion of Intervention

I have raised a formal regulatory issue for Sellafield Limited to carryout a review of the identified shortfalls and propose a suitable and proportionate corrective action plan.