Proposal of neutron resonance densitometry for particle like debris of melted fuel using NRTA and NRCA

NRTA及びNRCA法を組合せた中性子共鳴濃度分析法による粒子状デブリ分析の提案

原田 秀郎   ; 北谷 文人  ; 小泉 光生 ; 土屋 晴文 ; 高峰 潤 ; 呉田 昌俊   ; 飯村 秀紀  ; 瀬谷 道夫; Becker, B.*; Kopecky, S.*; Schillebeeckx, P.*

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

福島第一原子力発電所のような原子炉事故で発生すると考えられる粒子状溶融燃料中の核物質量を精度よく非破壊で計量するため、パルス中性子源を利用した中性子共鳴濃度分析法(Neutron Resonance Densitometry: NRD)を提案した。NRDは、中性子共鳴透過分析法(Neutron Resonance Transmission Analysis: NRTA)と中性子共鳴捕獲分析法(Neutron Resonance Capture Analysis: NRCA)を組合せた分析法である。本手法の分析原理、予備解析による測定精度及び開発計画について講演する。

The neutron resonance densitometry (NRD) has been proposed 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 is a combined method of NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis) using a pulsed neutron generator and a neutron TOF (time of flight) technique. The presentation includes the proposed NRD concept, its principle, and preliminary analytical studies on achievable accuracies. The research plan on the feasibility study of the NRD will be also shown, which has been started since 2012 JFY.