Measurement of Reactivity Effect and Thermal Neutron Flux in Non-uniformly Distributed Fuel Assemblies
Measurement of Reactivity Effect and Thermal Neutron Flux in Non-uniformly Distributed Fuel Assemblies
复制标题
非均匀分布燃料组件中反应性效应和热中子通量的测量
DOI：
10.3327/jnst.31.640
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发表时间：
1994
影响因子：
1.2
通讯作者：
K. Kobayashi
中科院分区：
文献类型：
--
作者：
Y. Yamane;Y. Hirano;S. Shiroya;K. Kobayashi
由于核燃料浓度的空间变化引起的反应性效应是后处理厂核临界安全的一个重要问题。作为一种从理论上估计这种反应效应的方法，Goertzel 的必要条件是众所周知的。为了研究这一理论预测，我们使用京都大学临界组件的固体慢化核心，系统地对由于燃料分布不均匀性造成的反应性影响进行了一系列测量。还使用金线激活方法测量了热中子通量分布。当具有相同的铀质量时，不均匀组件被发现具有 0.2%Δk/k 的过量反应性，因为均匀组件正是至关重要的。这种不均匀组件的中心区域的燃料浓度比均匀组件高 40%。此外，在这种非均匀组装中，由于热中子引起的金线反应速率的空间分布比均匀组装中更平坦……
A reactivity effect due to spatial variation of nuclear fuel concentration is an important problem for nuclear criticality safety in a reprocessing plant. As a method theoretically estimating this reactivity effect, the Goertzel's necessary condition is well known. To investigate this theoretical prediction, we have performed systematically a series of measurements of reactivity effect due to nonuniformity in the fuel distribution using a solid moderated core of the Kyoto University Critical Assembly. Thermal neutron flux distributions have been also measured using the activation method with gold wire. A nonuniform assembly was found to have an excess reactivity of 0.2%Δk/k when it had the same uranium mass as the uniform assembly was exactly critical. The fuel concentration of this nonuniform assembly was 40% higher in the center region than the uniform one. Moreover, the spatial distribution of reaction rate of gold wire due to thermal neutrons was flatter in this nonuniform assembly than in the uniform...