EDF Energy Nuclear Generation
Safety Case to allow continued operation of nuclear power stations.
Our wide range of engineering skills and ability to provide innovative solutions.
The UK has a fleet of ageing Advanced Gas-cooled Reactor power stations. There is an ongoing regulatory requirement to demonstrate that the reactors are safe to continue operating.
As part of this requirement, our client needed to demonstrate that the behaviour of the graphite core is understood, and that its future behaviour can be predicted – with good confidence – to a time beyond the operating period of the safety case.
One of the key ageing mechanisms which must be addressed within the safety case is the issue of graphite weight loss. Weight loss from the core occurs as a result of radiolytic oxidation in a carbon dioxide atmosphere.
Graphite weight loss can potentially affect the core’s ability to maintain the channel geometry, which is needed to allow unimpeded movement of fuel and control rods. It can also affect the core’s ability to provide neutron moderation to control the nuclear fission process.