This research focuses on developing a safeguards approach to assay 233Pa in thorium-based nuclear reactors. 232Th in a thorium reactor has a high neutron absorption cross section, leading to the creation of 233Th which then decays to 233Pa and subsequently decays to 233U - an IAEA-defined special fissionable material subject to safeguards. While 233U and thorium fuel are safeguarded, 233Pa (with a 27-day half-life) is not. This could create a gap in the overall verification of thorium-based fuel cycles, which could lead to the possibility of 233Pa diversion and unmonitored 233U production. This presentation identifies potential safeguards concerns of thorium-based reactors and presents approaches to ensure that 233Pa generation does not become a diversion path to amassed 233U material.
Year
2022
Abstract