电子辐照对高庙子钙基膨润土的性能影响

摘要/Abstract

摘要： 为研究电子辐照对高庙子钙基膨润土性能的影响,用电子辐照至不同累积受照剂量后,分析了微观结构和某些物化性质。结果表明:电子辐射作用引起了膨润土中蒙脱石晶胞参数的改变和晶粒尺寸的减小,结构中部分Si—O键和Al—OH键受到破坏,导致了阳离子交换能力和层电荷的降低、膨胀指数的减小、Si和Al溶解性增加以及对¹³⁷Cs和⁹⁹Tc吸附能力的减弱;与未经辐照样品相比,累积辐照至5 MGy时,样品的膨胀指数减小了18.65%,¹³⁷Cs和⁹⁹Tc分配系数分别减小了50.85%和58.58%,Si和Al溶解性分别增加了125%和199%。在地质处置回填材料设计和安全评价中,必须考虑电子辐射作用对膨润土性能的影响。

关键词: 膨润土, 电子辐照, 微观结构, 溶解性, 膨胀指数, 分配系数

Abstract: In order to study the effect of electron irradiation on the performance of Gaomiaozi Ca-bentonite, the microstructure and some physicochemical properties were analyzed with different cumulative radiation doses. The results showed that electron radiation changed the cell parameters and the size of montmorillonite, destroyed Si—O and Al—O bonds in the structure, reduced the cation exchange capacity and layer charge as well as expansion index, increased the solubility of Si and Al, and weakened the adsorption capacity of ¹³⁷Cs and ⁹⁹Tc. Compared with unirradiated samples, when cumulatively dose was up to 5 MGy, the swelling index reduced by 18.65%, the distribution coefficients of ¹³⁷Cs and ⁹⁹Tc decreased by 50.85% and 58.58%, and the solubility of Si and Al increased by 125% and 199%, respectively. It is proposed that the effect of electron irradiation on bentonite performance should be considered in the design and safety evaluation of backfill materials for geological disposal repository.

Key words: bentonite, electron irradiation, microstructure, dissolution, swelling index, distribution coefficient

中图分类号:

TL942

刘伟, 梁栋, 杨仲田, 刘宇辰, 李洪辉. 电子辐照对高庙子钙基膨润土的性能影响[J]. 辐射防护, 2022, 42(3): 244-251.

LIU Wei, LIANG Dong, YANG Zhongtian, LIU Yuchen, LI Honghui. Influence of electron irradiation on the performance of Gaomiaozi Ca-bentonite[J]. RADIATION PROTECTION, 2022, 42(3): 244-251.

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