90Sr、137Cs在某种包气带土壤中的迁移研究

本文叙述了放射性废物中具有代表性的裂变核素^90Sr、^137Cs在某种包气带土壤中的迁移情况研究。使用小型土柱的氚水淋洗实验研究土壤水力学性质，最后进行大型土柱实验研究核素在该包气带土壤中的迁移，并对实验情况进行了数学模拟。用该土壤原状土进行小型土柱的氚水淋洗试验，测得了土壤的水力弥散度为0．32cm，土壤有效孔隙度为0．35。经过290天的大型柱迁移试验表明，土壤对^90Sr的阻滞系数为220．4，在模拟实际降雨量的情况下，^90Sr的平均迁移速度为0．63cm/y，^137Cs在大型柱试验中没有明显迁移。数值模拟^90Sr、^137Cs迁移，得出经过上述大型柱试验相同的条件下，^90Sr、^137Cs迁移的峰位置基本和大型柱试验结果相同。

Study of Nuclide Migration in A Kind of Aerated Zone Soil

This paper represents the study of migration of~(90)Sr and~(137)Cs in a kind of aerated zone soil. The water dynamics nature of this soil was studied by tritium water experiment. At last, the migration of~(90)Sr and~(137)Cs in this aerated zone soil was studied through 290 days column dynamic adsorption-desorption experiment, and numerical simulation of the column experiment was conducted.Water dynamic dispersity and efficient porosity of this soil were measured by tritium water wash experiment. Value of water dynamic dispersity is 0.32cm, while value of efficient porosity is 0.35.Through 290 days soil column dynamic adsorption-desorption experiment, (retardation) factor of~(90)Sr was found to be 220.4. Under this simulated rainfall condition, migration velocity of~(90)Sr is 0.63cm/y. On the contrary, almost no migration of~(137)Cs was found.Under the same condition as the 290 days soil column experiment, the position of concentration peak of~(90)Sr and~(137)Cs got by numerical simulation was similar to the column experiment.