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Hunterston B power station

Safety regulator gives permission for the restart of Hunterston B reactor

By EDF | Posted August 20, 2019

We are pleased to confirm that the independent nuclear safety regulator, ONR, has given permission for EDF Energy to re-start Reactor 4 at Hunterston B power station.

The safety case for Reactor 4 has been subject to extensive scrutiny and testing: by our own internal Independent Nuclear Assurance, the Nuclear Safety Committee - a body of independent industry experts - and by the ONR themselves.

Since the decision was made to take both reactors off line last year, we have completed the most extensive investigation of the reactor core that has ever been undertaken.  This has provided us with valuable knowledge about condition of the graphite core.  As part of this programme we have worked with the University of Bristol to confirm our understanding of how the core would react in the event of a major earthquake, of a magnitude never experienced in the UK.

Along with Bristol University, we have been working with leading consultancies and expert academics at other universities across the UK including Strathclyde, Glasgow, Manchester, Oxford, Sussex, Nottingham and Durham as well as with leading UK companies such as Fraser-Nash, Wood and SNC-Lavalin.   We have also invested over 1000 person years into this research and invested over £125m in the programme.

As a result we have demonstrated that even in the most extreme conditions our reactors operate within large safety margins. In particular, all control rods would operate as they are designed to do and will safely shutdown the reactor in all circumstances. This has been agreed with the nuclear regulator, ONR, a statutory independent body which is representative of an industry whose regulatory regime is one of the most stringent and respected in the world.

It is important that we continue to monitor the core and so will perform frequent graphite inspections.  These will enable us to continue to demonstrate that the reactor operates with large margins to ensure safe operation at all times. 

We will continue to demonstrate this safety-first  approach throughout the operating lives of our nuclear fleet, up to and beyond the point when we decide to end the generation phase and begin defuelling and decommissioning.

The safety case for the return to service of Reactor 3 at Hunterston B has been submitted to the ONR for their consideration. 

You can see the ONR’s decision here and more information about the graphite programme here.

Hunterston’s low carbon power makes an important contribution to helping Scotland achieve its net zero carbon emissions. It avoided 1.3 million tonnes of carbon emissions in 2018, equivalent to taking 590,000 cars off the UK roads for a year.

For more information

EDF Media Team
24-hour press line: +44 (0)1452 652233