废树脂辐解气体对普通硅酸盐水泥矿物成分影响的热力学分析  

Thermodynamic Analysis for Effect of Waste Resin Irradiation Gason Mineral Composition of Ordinary Portland Cement

作　　者：韩旭 闫晓俊[1] 郭喜良[1] 席亚慧 秦翔 张丽 高凯 高超[1] HAN Xu;YAN Xiaojun;GUO Xiliang;XI Yahui;QIN Xiang;ZHANG Li;GAO Kai;GAO Chao(China Institute for Radiation Protection,Taiyuan 030006,China)

机构地区：[1]中国辐射防护研究院,山西太原030006

出　　处：《原子能科学技术》2023年第7期1321-1329,共9页Atomic Energy Science and Technology

摘　　要：水泥的矿物相成分及含量是影响水泥固化体性能的关键因素,本文基于热力学吉布斯自由能最小化方法,采用GEMS软件研究了废树脂辐解产生的H_(2)、CH_(4)、CO_(2)3种气体对普通硅酸盐水泥矿物相组成和矿物相总体积的影响。结果表明:仅有少量H_(2)和CH_(4)与水泥水化产物反应,造成高Ca/Si的矿物相溶解,矿物相的总体积基本稳定;辐解产生的CO_(2)会先与水泥水化产物中的羟钙石反应,羟钙石完全溶解后,硅酸盐矿物开始溶解,最后形成由大量碳酸盐和少量黏土矿物组成的体系,矿物相的总体积减小。本研究结果揭示了废树脂辐解产生气体引起水泥固化体降解的演变规律及机制,可为废树脂水泥固化体处置安全评价提供数据支撑。Recently,cement matrixes become a mainstream solution to address the stabilization of radioactive spent resins.Generally,the cumulative dose of spent resin cemented waste form will reach approximately 106 Gy over a disposal lifetime of 300 years.Due to the organic properties of spent resin,namely producing gas if being irradiated,it inevitably affects the mineral phase of cement waste forms.Therefore,the content and composition of the mineral phase could be key factors determining the performance of cement waste forms.With that in mind,in this paper,the influence of the above factors on ordinary Portland cement(OPC)was explored especially.Specifically,based on the Gibbs free energy minimization principle,the influence of three gases generated by irradiation of waste resin,namely H_(2),CH_(4)and CO_(2),on the mineral phase composition and total volume of ordinary Portland cement was discussed.Thereafter,the evolution of the mineral phase composition of ordinary Portland cement over time was investigated based on the rate of irradiated gas production.In this work,all the experiments were produced by GEMS software based on the thermodynamic Gibbs free energy minimization method.Meanwhile,the formulation for cement solidification of spent resin meets the standard of GB 14569.1-2011.From the experimental results,several important findings were obtained.Firstly,only a small amount of H_(2)and CH_(4)reacts with the cement hydration products,which causes the dissolution of the mineral phase with high Ca/Si,while the total volume of the mineral phase is almost invariant.Secondly,in the prior phase,CO_(2)first reacts with the portlandite in the cement hydration products.After the portlandite dissolute completely,the silicate minerals start to dissolve,forming a system composed of abundant carbonate and a few clay minerals,which decreases the total volume of the mineral phase.Thirdly,during the predicted 160 years,the effects of spent resin irradiation gases on the cemented waste form are consistently dominated by CH_(4)and

关 键 词：废树脂辐解气体 矿物相组成 吉布斯自由能 碳化作用 水泥降解 

分 类 号：TL94[核科学技术—辐射防护及环境保护]