title: Chemical State Mapping of Degraded B4C Control Rod Investigated with Soft X-ray Emission Spectrometer in Electron Probe Micro-analysis.
abstract: B4C is widely used as control rods in light water reactors, such as the Fukushima Daiichi nuclear power plant, because it shows excellent neutron absorption and has a high melting point. However, B4C can melt at lower temperatures owing to eutectic interactions with stainless steel and can even evaporate by reacting with high-temperature steam under severe accident conditions. To reduce the risk of recriticality, a precise understanding of the location and chemical state of B in the melt core is necessary. Here we show that a novel soft X-ray emission spectrometer in electron probe microanalysis can help to obtain a chemical state map of B in a modeled control rod after a high-temperature steam oxidation test.
authors.affiliation: Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Kasada
authors.affiliation: Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ha
authors.affiliation: Nippon Nuclear Fuel Development, Co., Ltd., 2163 Narita-cho, Oarai, Ibaraki 311-1313, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Higuchi
authors.affiliation: Nippon Nuclear Fuel Development, Co., Ltd., 2163 Narita-cho, Oarai, Ibaraki 311-1313, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sakamoto