本文在点中子动力学模型近似下,推导出在压水堆中中子噪声的均方根值与慢化剂温度噪声的关系。利用得到的关系,在反应堆各燃耗阶段计算中子噪声的均方根值,并把计算值与测量值进行比较。结果表明,利用慢化剂温度噪声作为低频(2 Hz以下)中子噪声的驱动源,能定量地解释中子噪声的均方根值随反应堆燃耗而增加的规律 In this paper, the neutron kinetic model approximates the relationship between the rms value of neutron noise and moderator temperature noise in PWR. Using the relationships obtained, the rms value of the neutron noise is calculated at each burn-in phase of the reactor and the calculated and measured values ​​are compared. The results show that the use of moderator temperature noise as a driving source for low frequency (below 2 Hz) neutron noise can quantitatively explain the law that the rms value of neutron noise increases with reactor burnup