ANALYSIS OF PASSIVE SAFETY SYSTEMS IN A SMALL/MEDIUM SIZE NUCLEAR REACTOR

The possibility of having a worldwide spread of nuclear energy, in next years, will be strongly affected by safety and management features of the new reactors. Projects in which passive systems are intensively used can guarantee the plant management without any external intervention in any plant condition. Beyond the traditional large sized nuclear reactors, can be possible a development of a parallel market, characterized by small/medium sized nuclear reactors which, thanks to their special features, allow developing special safety systems. The choice to prefer a small/medium sized nuclear reactor to a traditional size may be due to several factors including the possibility to use special safety systems developed ad hoc or the need of a small capital for the initial investment. Specifically will be analysed safety systems related with the decay heat removal, and passive systems which, in a different way, can guarantee the safety of the entire system. Several safety systems, some already developed for the MARS reactor while others derived from existing solutions will be critically analysed to identify what benefits can be effectively achieved, in terms of safety and economy.