Office for Nuclear Regulation

Mensa progress meetings and Mensa project compliance inspection of LC 19 and LC 20

Executive summary

Purpose of Intervention

The purpose of this intervention was to consider compliance with licence condition 19 Construction and Installation of New Plant, and licence condition 20 Modifications to Design of Plant under Construction on the Mensa project at AWE B site. 

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

The intervention is part of a series of planned interventions covered under the ONR weapons intervention strategy 2018/2019. The intervention rating is identified within the report.

Interventions Carried Out by ONR

The following interventions were carried out at the Mensa Project site:

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable

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

Licence Condition 19: In relation to the Mensa LC19 compliance inspection, I established that the construction and installation activities are progressing with a mechanical and electrical focus. Nuclear safety has been highlighted by the Mensa team and presentations have been rolled out. The main construction contractor has transitioned from Jacobs to Costain and a new project management structure with an increased AWE presence is in operation. Overall, I assessed that a ‘Green’ intervention rating was appropriate.

Licence Condition 20: In relation to the Mensa LC20 compliance inspection, I established that the project is approaching the submission of PCSR4 and following the construction activities associated with PCSR4, the project will take the opportunity to adopt the corporate arrangement for change management and categorisation. The change management process is well managed and documented. Overall, I assessed that a ‘Green’ intervention rating was appropriate. Due to time constraints, the details within the design change note (DCN) register and specific changes were not examined. A further intervention is to be scheduled for September to review the DCN register and a number of changes identified in the register.

Conclusion of Intervention

In relation to the Mensa LC19 and LC20 compliance inspections, I considered that Green ratings (No Formal Action) were appropriate.