APPARATUS AND METHOD FOR MEASURING NEUTRON SOURCE DISTRIBUTION

• Main Authors: GUNJI SATOSHI, YOSHIOKA KENICHI, KUMANOMIDO HIRONORI, HAYASHI YAMATO
• Format: Patent
• Language: English; Japanese
• Published: 01.12.2016
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASUREMENT OF NUCLEAR OR X-RADIATION; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To enable accurate measurement of neutron source distribution in a substance under measurement that contains burnt nuclear fuel.SOLUTION: According to an embodiment, a neutron source distribution measurement apparatus 100 includes: an external neutron source 14 that generates neutrons; a neutron source drive unit 16 capable of moving the external neutron source 14 to a close-by position in the proximity of a substance 1 under measurement containing burnt nuclear fuel and to a retreated position away from the substance 1 under measurement; one or more neutron detectors 11 that are disposed in the proximity of the close-by position to measure neutrons from the substance 1 under measurement; and a computation unit configured to receive outputs of the neutron detectors 11 when the external neutron source 14 is at the close-by position with respect to the substance 1 under measurement, outputs of the neutron detectors 11 when the external neutron source 14 is at the retreated position, and measurement point position information, to compute a distribution of relative values si of internal neutron source strength of the substance 1 under measurement.SELECTED DRAWING: Figure 1 【課題】燃焼した核燃料を含む物質である測定対象物質中の中性子発生源の分布状態を精度よく測定する。【解決手段】実施形態によれば、中性子源分布測定装置１００は、中性子を発生する外部中性子源１４と、外部中性子源１４を燃焼した核燃料を含む物質である測定対象物質１に近接した近接位置と、測定対象物質１から離れた後退位置とに移動可能な中性子源駆動部１６と、近接位置の近傍に設けられて、測定対象物質１からの中性子を測定する少なくとも一つの中性子検出器１１と、測定対象物質１において外部中性子源１４が近接位置の場合の中性子検出器１１の出力と、外部中性子源１４が後退位置の場合の中性子検出器１１の出力と、測定点の位置情報とを受けて、測定対象物質１の内部中性子源強度相対値ｓｉの分布を算出する演算部と、を有する。【選択図】図１