Core and transient design for a BWR of the next century

This paper reports on the progress of studies to establish the core and transient design for a Boiling Water Reactor (BWR) of the next century. A key emphasis for the core and transient design is flexibility in order to address changeable social conditions from the following aspects: Flexibility in operating cycle length. Flexibility in fuel discharge burnup. Flexibility in use of CU2 or MOx fuel. Other key emphases are improvement of operations and maintenance and reduction of plant costs. To address these areas, core design studies investigating potential benefits from alternate fuel assembly sizes and control strategies have been initiated. Means to mitigate the impact of transients are also under investigation in order to provide further improvement in operating margins which might in turn be used to enhance flexibility and reduce plant costs. (author)