JASPER実験データ集(III); 軸方向遮蔽実験

JASPER Experimental data book (III); Axial shield experiment

庄野 彰; 茶谷 恵治; 鈴木 惣十; 金城 勝哉

not registered; Chatani, Keiji; not registered; not registered

1980年8月から12月にかけて米国オークリッジ国立研究所にて実施された軸方向遮蔽実験データ及びその実験に関するデータをまとめた。この実験は,高速炉の炉心上部へ漏洩する放射線を低減するために燃料集合体上部に設けられる軸方向遮蔽体の遮蔽特性を研究するために実施したものである。3種類の遮蔽設計概念,2種類の使用材料(ステンレス鋼と炭化ほう素)について,それらの特性を比較するための実験体系が構成された。この実験体系にガスプレナム領域のスペクトルを代表するものに変換された放射線ビームが入射され,実験体系後方に漏洩する中性子の特性が各種検出器により測定された。

This report is intended to make it easier to apply the measured date obtained from the Axial Shield Experiment, which was conducted at the Oak Ridge National Laboratory (ORNL) in 1990 as part of a series of eight experiments planned for Japanese-American Shielding Program for Experimental Research (JASPER) program starting in 1986. The Axial Shield Experiment was planned to study the neutron attenuation characteristics of the axial shield, which is designed in the fuel assembly to reduce the neutron fluence in regions above the core. In order that the experimental neutron spectrum would be representative of the expected neutron spectra directly above the FBR core, the Tower Shielding Reacor (TSR) source spectrum was altered by a spectrum modifier, which was used in two previous experiments also. The modified spectrum entered the test section, which consisted of seven hexagonal shield assemblies surrounded by B,C and concrete. Three different axial shield designs were studies, Either B,C or stainless steel was used as a shielding material. Neutron measurements were made with various detectors behind the experimental configurations. Information presented in this report is based mainly on a report issued by ORNL (ORNL/TM-11839, "Measurements for JASPER Program Axial Shield Experiment"). Additional information reported by the PNC assignee is utilized also.