The development of the next generation ABWR (AB1600)

Toshiba is developing a next generation ABWR of 1600 MWe, which we tentatively call as AB1600. To retain core damage frequency equivalent to ABWR, to strengthen countermeasure for severe accident (SA), and to improve economical efficiency, the passive containment cooling system (PCCS) and the gravity driven core cooling system (GDCS) and the isolation condenser (IC) are introduced. By introducing passive safety systems, the composition of the emergency core cooling system (ECCS)/heat removal system can be reduced to two divisions configuration from three divisions configuration of ABWR. This configuration change contributes to improvement of economical efficiency by attaining amount-of-resources reduction in not only main systems but also auxiliary systems. Moreover, with the introduction of large fuel bundle, the number of fuel bundles and control rods can be reduced. As the result, the AB1600 has the possibility attaining both economical and safety goals by simplification of system and enhancement of countermeasure for SA. (author)