Feasibility studies and development of NDA technologies for NM in the melted fuels of Fukushima-Daiichi NPP

Seya, Michio; Harada, Hideo   ; Kitatani, Fumito  ; Koizumi, Mitsuo ; Hajima, Ryoichi; Hayakawa, Takehito; Angell, C.; Bolind, A.

This paper describes Neutron Resonance Densitometry (NRD) based on NRTA (Neutron Resonance Transmission Analysis) and NRCA (Neutron Resonance Capture Analysis) utilizing the TOF (Time of Flight) method, which is intended for the analysis of particle-like debris, in terms of feasibility studies. This paper also describes an NDA technology using LCS (Laser Compton Scattered) -rays (mono-energetic -rays) to analyze other types of debris (small rock like debris or kcut shaped debris) by the Nuclear Resonance Fluorescence (NRF) method. For LCS- NRF technology the measurement of scattered NRF -ray and a novel transmission measurement using NRF is also shown roughly, which has the advantage of being insensitive to the radioactive nature of the fuel and is completely insensitive to the geometry of the fuel.