Passive Gamma Spectrometry of Low-Volatile FPs for Accountancy of Special Nuclear Material in Molten Core Material of Fukishima Daiichi Nuclear Power Plant - Overview and Research Plan

For the nuclear material accountancy of molten core material in Fukushima Daiichi unit 1, 2 and 3, feasibility studies of a variety of technologies are being performed. As one of the technologies, feasibility study of passive gamma spectroscopy of low-volatile fission products (FPs) for nuclear material accountancy in molten core material has been performed with reviewing TMI-2 experience, and the correlation of actinides and FLs inventory in BWR spent fuel was reported, considering the sensitivity of axial neutron spectrum, void, burnup, enrichment distribution unique to BWR furl. In the present paper, the overview, measurement condition, and some results of fundamental tests are presented.