SAFETY CONCEPT OF THE SWR 1000, AN ADVANCED BOILING WATER REACTOR WITH PASSIVE SAFETY FEATURES

摘要

The safety concept of the SWR 1000 satisfies the requirements to be met by advanced reactor designs. The combination of active and diverse passive safety systems for both initiating and performing safety functions ensures full compliance with the principle of diversity. If all active systems such as I&C equipment, emergency power supplies and RHR/LPCI systems should fail, all postulated accidents (whether transients or LOCAs) can be controlled by just the passive systems alone without resulting in heatup of the core and with a grace period of more than 72 hours available before operator intervention becomes necessary. The frequency of occurrence of core damage states has been able to be reduced by more than one order of magnitude compared to that of existing light water reactors. A postulated core melt accident can be controlled by the passive systems alone in such a way that the consequences of the accident remain restricted to the plant itself and there is no need for large-scale emergency response actions in the vicinity of the plant. By introducing passive systems which are less expensive than active systems and combining these with a reduced number of active systems, this improved safety concept additionally meets requirements for a competitive plant cost.