Development of a High-Conversion Boiling Water Reactor

Light water reactors (LWRs) are expected to be a primary source of electrical power in Japan into the 21st century. A next-generation LWR must be developed that efficiently uses uranium resources and improves fuel economy. A high-conversion boiling water reactor (BWR) core design is proposed that conserves natural uranium through a high conversion ratio that is achieved through efficient utilization of the vapor void in the BWR core. The proposed reactor concept employs fuel bundles with a square channel box and cruciform control rods, which are commonly used in conventional BWRs. Thus, it is possible to use current BWR core internals and vessel designs with minimal modifications, which makes the entire reactor system design more feasible.