Integration of new technologies for the next generation BWR reactor assembly

Because of the long lead time needed to design and build an evolutionary type nuclear reactor and also due to the expected needs for additional light water nuclear power plants in the next century in Japan, GE, Hitachi, and Toshiba jointly participated in a study to develop the next generation advanced boiling water reactor (ABWR). The study has been conducted in two phases over the last four years, under the guidance of Tokyo Electric Power Co. and other Japanese utilities. The design has progressed from early innovative concepts, through a phase of feasibility studies, to the selection of reference design concepts. In order to maintain the reactor vessel the same size as the current ABWR yet increase the amount of fuel and therefore the power level of the core, a shroudless design has been adopted. This design in combination with larger fuel bundle has allowed the accommodation of a 1,500 MWe or 1,700 MWe core, while reducing the number of components such as control rod drives and control rods plus the elimination of the standard shroud. This paper summarizes the conclusions of the Phase 2 study and the current reference design. This paper will highlight those components and areas where major design changes have been selected to represent the reference design, the reason for their selection and their overall impact upon design and performance