It can be seen from the tracer migration test results that the centers of mass of specific activity distribution of radionuclides

60 Co

85 Sr and 134 Cs

in unsaturated loess medium are still within tracer source layer under natural rainfall condition during about 3 years. And lateral specific activity distribution variance of 85 Sr is equivalent to that of longitudinal distribution. Migration distances of the radionuclides under artificial sprinkling condition are also small. It is shown from the result that unsaturated loess has stronger sorption capacity to the radionuclides. In other words

unsaturated loess can be one of the candidate of geological media for disposal of ILRW. Moreover

it can be seen that the amount of water infiltration affects obviously downward migration velocity and longitudinal spread of radionuclide

and hence control of water infiltration amount through repository is a very important measure for decreasing effect of radionuclides in disposed waste on environment according to fitting and analyses to the tracer migration test results.