A New Boiling Water Reactor Core Concept for a Next-Generation Light Water Reactor

A new boiling water reactor (BWR) core concept that meets various requirements for a next-generation light water reactor is proposed. This BWR core can be operated as either a high-burnup core or a high-conversion core simply by replacing the fuel assemblies and control rods.The high-burnup core is suitable for a once-through nuclear fuel cycle and has a low fuel cycle cost due to the adoption of advanced spectral shift technology. The high-conversion core is suitable for nuclear fuel recycling and reaches a high-conversion ratio by adopting a tight-lattice arrangement of mixed-oxide fuel rods in the fuel assemblies and using control rods with a zirconium follower. The reactor structures are essentially identical, and they are designed to be as simple as the current BWR to achieve high reliability. The reactor core also has high operability due to the spectral shift water rods that are operated with all control rods withdrawn. At reactor shutdown, the core has a large reactivity control capability due to the cruciform control rods with wider blades and has an ample safety margin.