300#反应堆瞬发中子衰减常数测量

Measurements of Prompt Neutron Decay Constant for 300# Research Reactor

利用反应堆噪声分析技术测量300#池式研究堆缓发临界下的瞬发中子衰减常数。堆芯采用低富集度U燃料装载,燃料元件带一定燃耗。利用紧靠堆芯布置的两个中子探测器,信号经测量系统和相关软件得到互谱密度,用非线性最小二乘法拟合得到瞬发中子衰减常数。在4 kW功率水平测得缓发临界下的瞬发中子衰减常数cα=(83.4±0.7)s-1。

The prompt neutron decay constant was measured by using reactor noise technology at delayed criticality for 300# pool research reactor. The reactor core uses irradiated low-enrichment fuel loading. The prompt neutron decay constant is obtained from nonlinear least-squares fitting of the cross-power spectral densities measured between two detectors placed adjacent to the core. The measured prompt neutron decay constant αc at deiayed criticality with a power of 4 kW is （83.4±0. 7） s^-1.