Decay heat experiment on thirty-two fusion reactor relevant materials irradiated by 14-MeV neutrons

Abstract

Highly accurate calculation of decay heat is important in safety designs of fusion reactors against loss of coolant/flow accidents. To provide experimental data of decay heat needed for validation of the design calculations, a systematic decay heat experiment was performed. Thirty-two fusion reactor relevant materials were irradiated by 14-MeV neutrons, and decay heat produced in the materials was measured by the Whole Energy Absorption Spectrometer in a cooling time period from 1 min to 400 days with typical experimental errors of 6–10%. Source neutron flux spectra at irradiation positions, which were needed for successive analyses, were determined. Lessons about sequential reactions, impurities, reactions induced by low energy neutrons and radiolysis which should be considered in activation analyses for fusion reactors were learned from the experimental analyses. The experimental data with the source neutron conditions are to be used for investigating the validity of decay heat calculation codes, activation cross section libraries and decay data libraries.