摘要
3 H和99Tc是低中放废物处置中 2个重要的核素 ,在处置场的安全评价中十分重要 .由于介质对3 H和99Tc的吸附较弱 ,常忽略其滞留性 ,并用3 H标定地下水的流速 .野外实验表明 :在包气带中 ,黄土对99Tc的吸附大于3 H ;在含水层中 ,黄土对3 H迁移的影响大于99Tc.本文根据实验数据 ,采用非平衡吸附模式NESOR程序分别模拟了3 H和99Tc在黄土包气带和含水层中的迁移过程 .模拟结果表明 :99Tc在黄土包气带中的分配系数范围为 0 0 5～ 0 0 5 5mL/g ;3 H在黄土含水层中分配系数为 0 1 1 6mL/g ,该参数是黄土对3 H和99Tc综合影响的结果 ,其滞留机理尚待研究 .
H and 99Tc are important nuclides in low and intermediate level radioactive wastes, and in safety assessment of near surface repository their migration characteristic usually determines the computing result. The medium of loess appears to possess the characteristic of weak adsorption ability to 3H and 99Tc when they are migrating in it, so the adsorption ability are often neglected, and 3H are used to identify groundwater velocity. But in the field test it was showed that in the aerated zone loess possesses stronger adsorption ability to 99Tc than to 3H, and in the aquifer the stronger adsorption ability to 3H than to 99Tc. In this paper the migration tests of 3H and 99Tc were simulated by NESOR program of non-equilibrium adsorption model. The results show: 99Tc distribution coefficient ranges 0.05～0.055mL/g in the aerated zone, 3H distribution coefficient is 0.116mL/g in the aquifer, and the parameter reflects integrated impact of loess on 3H and 99Tc, and the mechanism of them being retarded still need proving.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2003年第6期48-53,共6页
Environmental Science
基金
国家自然科学基金资助项目
水利部黄河水利委员会资助项目 (5 0 2 390 10 )
国家重点基础研究发展规划项目 (G19990 436 0 6 )
