Performance evaluation of differential die-away system in an integrated active neutron NDA system for nuclear non-proliferation and nuclear security

核不拡散・核セキュリティ用統合型アクティブ中性子非破壊測定システムのダイアウェイ時間差分析装置の性能評価

大図 章  ; 前田 亮  ; 米田 政夫   ; 藤 暢輔   

Ozu, Akira; Maeda, Makoto; Komeda, Masao; Toh, Yosuke

A Differential Die-away Analysis (DDA) system using a compact pulsed neutron (DT: 14 MeV) generator has been successfully developed for nuclear non-proliferation and nuclear security in the Japan Atomic Energy Agency. The DDA system employing the fast neutron direct interrogation method is designed to quantify fissile materials in samples which have different volume from a vial bottle (4 cc) to pail container (20 liter). It has been demonstrated experimentally that the DDA system is capable of quantifying a nuclear fissile material (Pu-239) less than 10 mg in a vial bottle. The performance of the DDA system with a large measurement sample such as a MOX can container (2 liter) was evaluated through the Monte Carlo simulation studies. The simulation results show that the Pu-239 mass of around 10 mg even in the MOX can container can be detected. The results of the simulation study are discussed and compared to those of the experimental test.