REACTOR CONTROL ROD DESIGN METHOD AND REACTOR CONTROL ROD EVALUATION METHOD

摘要

PROBLEM TO BE SOLVED: To easily determine reactivity worth and nuclear lifetime in a method of designing or evaluating a control rod for boiling-water reactor.SOLUTION: A control rod for reactor is configured by separately disposing two plate-like vane pieces 17 each composed of hafnium neutron absorber, constituting each vane 11 by using a plate-like neutron absorber spacer 18 for a length of at least 1/4 full effective length from a distal end side in an insertion/ejection axis direction between both the vane pieces 17, and cross coupling four vanes 11. Among a function of effective thickness of hafnium in the vane piece 17, a function of an absorber spacer width (x), a function of an axial center water area width (w), a function of a non-absorber section width (v) in installation inside vane pieces and a function of vane thickness B, the reactivity worth is represented as functions of the effective thickness of hafnium and the absorber spacer width (x) at least in the vane pieces.