模拟核素固化体SrZr_xTi_(1-x)O_3的化学稳定性  

Chemical stability of simulated waste forms SrZr_xTi_(1-x)O_3

作　　者：牟婉君[1] 李兴亮[1] 余钱红[1] 蹇源[1] 魏洪源[1] 杨玉山[2] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,绵阳621900 [2]西南科技大学国防学院,绵阳621900

出　　处：《核技术》2015年第9期18-23,共6页Nuclear Techniques

基　　金：中国工程物理研究院科学基金(No.2012cx03)资助

摘　　要：为研究90Sr衰变子体对90Sr Ti O3固化体结构稳定性的影响,以C4H6O4Sr·0.5H2O、Ti O2及Zr OCl2·8H2O粉体作为原料,按照化学计量比Sr ZrxTi1-xO3(0≤x<1)设计配方,采用高温固相法制备一系列固化体。利用X射线衍射光谱(X-ray Diffraction,XRD)、扫描电镜(Scanning Electron Microscope,SEM)及红外(Fourier Transform Infrared,FT-IR)谱仪对制备固化体的物相、结构和微观形貌进行分析表征,并对其抗浸出性能和辐照性能进行了研究。结果表明,当x<0.5时,固化体为单一物相;当x≥0.5时,固化体中出现第二相。固化体中的Sr2+、Zr4+的浸出浓度随浸泡时间而增大,在浸泡42 d时,Sr2+的最大浸出浓度为0.006 5μg?m L-1,Zr4+的最大浸出浓度为0.01μg?m L-1。Background： 90Zr is a decay product of 90Sr, which may induce structural changes of radioactive waster forms. Purpose： In order to study the influence of decay product on the stability of perovskite-type SrTiO3 used for immobilizing 90Zr, C4H6O4Sr.0.5H2O, TiO2 and ZrOCl2.8H2O are used as the starting materials. Methods： The Zr-doped SrTiO3 synthesized can be generally represented as SrZrxTi1？xO3 （0≤x〈1） with the high temperature solid reaction. The phases, structure and microcosmic shape of synthetic condensates were characterized by the X-ray Diffraction （XRD）, Scanning Electron Microscope （SEM） and Fourier Transform Infrared （FT-IR）, and long-term chemical stability was studied at constant temperature of 90 oC. Results： The results indicate that the second phase of compounds is observed when the value of x is more than 0.5. The leaching rate of Sr2＋ and Zr4＋ in waste forms increase with the immersion time, while the highest leaching ratios for 42 d are no more than 0.006 5 μg.mL-1 and 0.01 μg.mL-1, respectively. The crystalline phase and morphology of solidified SrZrxTi1-xO3 waste form are influenced by electron beam irradiation. Conclusion： This study results may provide technical support for long-time immobilization of the 90Sr.

关 键 词：钙钛矿 固化体 抗浸出性能 辐照 

分 类 号：X591[环境科学与工程—环境工程] TL941.33[核科学技术—辐射防护及环境保护]