Office for Nuclear Regulation

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Site inspection of Hunterston A

Executive summary

Purpose of intervention

This report covers interventions in pursuit of the ONR integrated intervention strategy for Hunterston A, in particular to address regulatory issues identified as part of Inspection plan and carry out the planned Compliance inspections

Interventions Carried Out by ONR

This report covers interventions at Hunterston A mainly to address Compliance inspection and follow-up of regulatory actions placed on the site from previous inspections as follows:

Explanation of Judgement if Safety System Not Judged to be Adequate


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

Only the Compliance inspections and follow–up inspections are included in the executive summary as all other interventions are for information only.

LC 7 - The purpose of the intervention was to follow up the intervention carried out in November 2014 on LC7 to address the regulatory issue about adopting the corporate standard for investigation which had been in place since December 2013. On the basis of the inspection carried out and the documentation reviewed and individuals engaged, I find the issue to be addressed and the site to have appropriately adopted the Magnox corporate standard in investigations.  I therefore will close this issue formally on the issues database.

LC20 - The purpose of this intervention was to undertake an inspection of the LC 20 arrangements and their implementation on site.  Site Licence Condition 20, ‘Modification to design of plant under construction’, requires the licensee to ensure that no modification to the design which may affect safety is made to any plant during the period of construction except in accordance with adequate arrangements made and implemented by the licensee for that purpose. The inspection considered the implementation of arrangements associated with the SILWE project with regard to Technical Queries (TQS) and the judgements made as to whether these TQs constitute design changes or not.  ONR noted there were no written records of judgements as to whether TQs constituted a design change.  Additionally, it noted that there were no formal records of the assessment of relevant TQs by project design specialists.  There was also no process for considering TQ s that had been raised over a period of time and whether there was a holistic impact on the design or safety position. In conclusion, for Site Licence Condition 20, ‘Modification to design of plant under construction’, I consider the position to be significantly below standard because the licensee’s implementation of the arrangements falls short of what would reasonably be expected for the adequate control of modifications to the design of the plant under construction.  The requirement is to address the shortfalls with the implementation of adequate arrangements.  A level 3 issue will be raised on the ONR issues database and a letter sent to site to address the issue.  This issue will address the position with regards to record keeping associated with the decision making and also configuration control associated with the variations.  There will in the next financial year be a further inspection under LC 20 to assess if these shortfalls have been addressed.  Additionally, the site has given a commitment to undertake a site-wide review of LC 20 on projects, in conjunction with a corporate centre team.

LC 36 - The purpose of the intervention was to undertake and inspection of the license arrangements and implementation under LC 36. LC36, ‘Organisational capability’, requires that the licensee provide and maintain adequate financial and human resources to ensure the safe operation of the licensed site, and make and implement arrangements to control any change to the organisation or structure which may affect safety.  ONR reviewed the site baseline document and the validation and resilience documents associated with the baseline, which have been produced in line with the company arrangements.  In conclusion, with regard to LC 36 – Organisational Capability, I consider the position to be adequate, although there are a number of areas for improvement and also the resilience review may be more difficult this year owing to reduced resources.

Conclusion of Intervention

The inspection raised issues regarding the arrangements under LC 20 and thus a letter will be sent to the site and an issue placed on ONR’s issues database.  The issue will need to be monitored and a further inspection of LC 20 is planned at an appropriate time to allow consideration of new arrangements by the licensee to address ONR’s concern.