The aim of this report is to examine whether there are any international variations in the electrical power system designs (“design variations”) of nuclear power plants that affect the system response when subjected to relevant disturbances. The ambition is to collate views and experiences in this area or suggestions for further investigations, providing an overview to stimulate discussions on the utilisation of the “best available technology”.
For this first study, the scope was defined as “power supplies in general but electrical power supplies in particular”. The rationale was that the energy required to fulfil necessary safety functions may be provided by any type of energy source and a key strategy to mitigate unanticipated failure modes is to provide as strong independence as reasonable between redundant functions, with a diversification of energy sources potentially providing a strong decoupling of failure modes.