Neutron resonance densitometry for particle-like debris of melted fuel

Harada, Hideo   ; Kitatani, Fumito  ; Koizumi, Mitsuo ; Takamine, Jun ; Kureta, Masatoshi   ; Tsuchiya, Harufumi ; Iimura, Hideki  ; Seya, Michio; Becker, B.*; Kopecky, S.*; Schillebeeckx, P.*

Feasibility study of neutron resonance densitometry (NRD) has been started to quantify of nuclear materials in particle-like debris of melted fuel formed in severe accidents of nuclear reactor such as Fukushima Daiichi Nuclear Power Plants. The NRD here is a combined method of NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis) using a pulsed neutron generator and TOF (time of flight) measurement. The presentation includes the proposed compact NRD system, the spectrometer design for NRCA using LaBr detectors by Monte Carlo simulations, and analytical studies on achievable accuracies. The experimental results using particle-like Cu samples measured at the GELINA facility in IRMM are also shown in comparison with analytical studies. Required nuclear data for the NRD will be also discussed.