辐照和热耦合作用对改性钠基膨润土铯吸附影响研究  

Coupling effects of thermal andγirradiation on the adsorption performance of bentonite to Cs

作　　者：赵帅维[1] 毛亮[1] 白锦绣 刘伟[1] 贾梅兰[1] 赵彦东 李洪辉[1] 高超[1] 杨仲田[1] ZHAO Shuaiwei;MAO Liang;BAI Jingxiu;LIU Wei;JIA Meilan;ZHAO Yandong;LI Honghui;GAO Chao;YANG Zhongtian(China Institute for Radiation Protection,Taiyuan 030006)

机构地区：[1]中国辐射防护研究院,太原030006

出　　处：《辐射防护》2024年第6期687-694,共8页Radiation Protection

摘　　要：为阐明γ辐照和热耦合作用对缓冲材料吸附性能的影响,本文以内蒙古兴河县高庙子改性钠基膨润土为研究对象,采用批式法测定了γ辐照和热耦合作用前后^(137)Cs在钠基膨润土中的吸附分配系数。结果显示,在85~610 Gy/h的剂量率范围和0.28~0.74 MGy的累积剂量范围内,γ辐照和热同时作用的实验条件可增强钠基膨润土对^(137)Cs的吸附能力,钠基膨润土对^(137)Cs的分配系数随剂量率的增大逐渐增大,较未辐照原土增量在38.5%至46.8%之间。但在更高剂量率(2.9 kGy/h)下增量平均值回落至33.7%。在0.28~5 MGy区间未发现显著的累积剂量效应。在此基础上,建立了高放废物地质处置库核素释放、迁移和剂量估算试评价模型,使用GoldSim安全评价软件和试验所得钠基膨润土的分配系数,模拟计算135 Cs在参考景象下的释放率和辐射影响,结果表明,膨润土受到来自废物体的辐照后可将135 Cs的近场释放率峰值时间推迟约6000 a,峰值降低约27%。In order to study the influence of gamma-ray irradiation and thermal simultaneous action on the absorption property of buffer material,this study is based on the modified sodium bentonite which is from Gaomiaozi.The distribution coefficients of^(137)Cs are measured separately in the modified sodium bentonite and the modified sodium bentonite undergoing gamma-ray irradiation and thermal simultaneous action by batch method.The experiment results show that gamma rays irradiation and thermal simultaneous action helps improve the ability to absorb^(137)Cs on the sodium bentonite under the experimental conditions.Compared with the modified sodium bentonite,the increment is in the range of 38.5%to 46.8%.A pilot evaluation model for nuclide release,migration,and dose estimation of the HLW geological repository was established.GoldSim safety evaluation software was used to simulate the release rate in the near and far field and radiation effects on the biosphere of 135Cs under the reference sites.The simulation results show that the ambient dose caused by 135Cs can be reduced by increasing the thickness of bentonite after being irradiated by waste.

关 键 词：改性钠基膨润土 辐照和热耦合作用 铯 分配系数 迁移模拟 

分 类 号：TL942[核科学技术—辐射防护及环境保护]