SiO2热中子散射截面在空间堆事故分析中的应用

摘要

SiO2热化效应可能对核废料地质储存库分析和空间反应堆坠落湿沙情况下的临界安全造成一定影响。本文结合最新的ENDF/B Ⅶ.1的TSL库，制作了ACE格式的SiO2热中子截面数据库。分析了不同温度对SiO2热中子散射截面的影响，比较了采用声子谱模型的SiO2热中子散射截面数据与采用自由气体模型的SiO2热中子散射截面数据的差异，并采用本文制作的截面库，对空间堆坠落湿沙情况下的临界安全特性进行了分析，给出了反应堆最易重返临界的湿沙成分比例。%T hermal neutron scattering of SiO2 may have the impact on analysis of the ge-ologic storage of nuclear waste and criticality safety of space reactor ’s falling accident . The ACE format SiO2 thermal neutron cross sections were generated by using the new TSL library of ENDF/B Ⅶ.1 .Cross sections at different temperatures were investiga-ted .Comparison of SiO2 thermal neutron scattering cross sections between phonon mod-el and free gas model was done .The space reactor’s criticality safety in wet sand was analyzed by using the new library ,and the harmful moderating proportion of wet sand w as given .