18 March 2019
Dear SSG Member,
As a member of our community, I believe it is important to keep you updated on any developments at Hunterston B Power Station.
In March 2018, Hunterston Reactor 3 came offline to carry out routine inspections of the graphite core. The inspections confirmed the expected presence of cracks and also identified these happening at a higher rate than modelled.
Since we took the unit off we have completed an extensive inspection programme, one of the most detailed of its kind in the world. We’ve also taken time to perform further inspections on Reactor 4 so we know what condition both cores are in.
In that time we’ve improved the modelling of the reactor operation in normal conditions and in a highly unlikely earthquake, and we can show conclusively that it will operate and shutdown as designed, with absolutely no erosion of safety. In all circumstances all control rods will enter the core and there is no challenge to safe operation.
Neither EDF Energy nor ONR, the UK nuclear safety regulator, would ever allow the Hunterston reactors to restart unless completely satisfied that it is safe to do so.
Following the core inspections and extensive modelling, the safety case providing the justification for return to service of Reactor 4 has been provided to ONR for their assessment. The ONR will, completely independently, review the case before deciding whether or not to approve for return to service. It is not possible for us to confirm with certainty how long this process will take; our top priority is that it’s completed with appropriate rigour.
Energy market rules require us to provide our most likely view of return to service dates.
To support time for the ONR assessment, we have declared 30 April 2019 for Reactor 4.
The Reactor 3 safety case is currently going through our internal process of independent review. On completion it will be submitted to the ONR for their assessment. To allow sufficient time for this we have declared 30 June 2019 for return to service of Reactor 3.
More information regarding graphite can be found on our website.
You can also view short film about the graphite programme here.
I hope this information is useful to you as a member of the Site Stakeholder Group. Should you wish to ask any questions please feel free to ring the Station on 01294 826000 and ask for our Communications Officer, Nikki Thomson.
Dr Roddy Angus
Acting Station Director