Promising NDA technologies for material accountancy of nuclear material in debris of melted fuel of Fukushima-Daiichi NPP

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

This introductory paper presents two promising NDA technologies for nuclear material accountancy of melted fuel debris of Fukushima Daiichi NPP, which JAEA has been developing basic part of them. One of the two is Neutron Resonance Densitometry based on NRTA and NRCA utilizing the Time of Flight method, which is intended for the analysis of particle-like debris. We JAEA and JRC-IRMM have started collaboration on NRD since May 2012. This paper describes the proposed NRD very roughly, while the some of the papers show the details of this method. Another NDA technology uses LCS -rays to analyse nuclear material in cut / small rock-like debris. The application of the Nuclear Resonance Fluorescence method using LCS -rays is presented here very roughly. Last 2 papers in this series show in detail the demonstration system of generation of intense mono-energetic -rays using Energy Recovery Linac and laser storing cavity and measurement methods.