Modern light water reactors - EPR and SWR 1000. Present status and possibilities of development and application

Framatome ANP has focused its efforts on two development projects in the field of light water reactor technology: the EPR (capacity 1500-1600 MW) and the SWR1000. The main goals pursued in developing the two product lines are: to increase nuclear plant safety even further compared to existing plants and to achieve power generating costs that are competitive with those of fossil-fired power plants. Some key advances made during the development that are particularly characteristic of the EPR and SWR are discussed. For the EPR the main safety systems are: double wall containment, containment heat removal system, four train redundancy for main safeguard systems etc. The physical separation of the systems as regards ventilation as well as by concrete walls rules out the possibility of multiple failures caused by fire, flooding or sabotage. In case od a core-melting accident the specially developed depressurization system reduces primary system pressure to < 20 bar. Various PSA have been conducted resulting in the development of a well-balanced system and component designs and avoiding dominant accident sequences from power and shutdown states.One major feature of the SWR 1000 are the passive safety systems, developed, tested and integrated into the design. They are: Containment cooling condensers for heat removal; Safety Relief Valves; Emergency condensers for heat removal from the RPV; Flooding lines for passive core flooding in the event of a LOCA; Drywell flooding line (core-melt accident). Accidents can be controlled both by active and passive systems. PSA has been also conducted. Some economic aspects are discussed in the paper