Experimental cores for benchmark experiments of effective delayed neutron fraction βeff at FCA

Abstract

Three cores were built for benchmark experiments of the effective delayed neutron fraction β eff at the FCA facility of the Japan Atomic Energy Research Institute: the XIX-1 core fueled with highly enriched uranium; the XIX-2 core fueled with plutonium and natural uranium; the XIX-3 core fueled with the plutonium. Measurements were carried out for the criticality, the central fission rates, the fission rate distributions and the reactivity worth distribution of 252Cf source in these cores as core characterizations. Semi-experimental values for several parameters integrated in whole reactor were determined using these measured distributions and calculated corrections.