摘要
自给能中子探测器(Self-Powered Neutron Detector,SPND)的长期性能对先进反应堆的安全运行具有重要意义。然而,当前相关研究多依赖于计算成本较高的蒙特卡洛模拟或在役实验数据,缺乏统一的解析理论框架。本研究采用发射体反应解析方法,通过核反应与衰变方程,推导得到铑、钒、钴三种SPND灵敏度随时间及累积中子注量演变的数学模型。研究结果显示,铑SPND的灵敏度呈高燃耗驱动的指数衰减趋势;钒SPND因核反应截面极低,在整个服役期内灵敏度近乎恒定,其寿命主要由材料耐受性决定;钴SPND则受制于因燃耗产物钴-60累积造成的本底信号污染,为此,本研究引入了“信息寿命”概念进行量化。本研究揭示了主流SPND长期性能内在物理规律,为SPND的可靠性评估及反应堆堆芯在线监测提供了理论参考。
The long-term performance of Self-Powered Neutron Detectors(SPNDs)is crucial for the safe operation of advanced nuclear reactors.However,current research predominantly relies on computationally expensive Monte Carlo simulations or in-pile experimental data,and a unified analytical framework is lacking.This study employs an emitter-reaction-based analytical method,utilizing nuclear reaction and decay equations,to derive mathematical models for the sensitivity evolution of rhodium,vanadium,and cobalt SPNDs over time and accumulated neutron fluence.The results show that the sensitivity of rhodium SPNDs exhibits an exponential decay driven by high burnup.Vanadium SPNDs maintain nearly constant sensitivity throughout their service life due to their extremely low nuclear reaction cross-section,with their lifetime primarily determined by material endurance.Cobalt SPNDs,however,are limited by background signal contamination caused by the accumulation of the burnup product cobalt-60.To address this,this study introduces the concept of"information lifetime"for quantification.This research reveals the intrinsic physical laws governing the long-term performance of mainstream SPNDs,providing a theoretical reference for SPND reliability assessment and SPNDs'in-core online monitoring.
作者
王天喜
李俊
别业旺
李钊同
李克亮
WANG Tianxi;LI Jun;BIE Yewang;LI Zhaotong;LI Keliang(Nuclear and Radiation Safety Center,Beijing 100082,China;China institute of atomic energy,Beijing 102413,China)
出处
《核电子学与探测技术》
北大核心
2025年第11期1742-1749,共8页
Nuclear Electronics & Detection Technology
