Field study of the migration of⁹⁰Sr in a weak loess aquifer

The migration of Sr-90 in a weak loess aquifer was investigated in-situ in an Underground Research Facility. Quartz containing Sr-90, H-3 and other nuclides was introduced into the aquifer with a stainless steel pipe. The local water flow field in the aquifer was monitored using a 3-dimensional sampling system. The contaminated area of the aquifer was marked out wholly with the help of a pre-installed stainless steel frame and cut into small pieces (samples) 3-dimensionally, and analyzed. The result of the 3-year experiment indicated that Sr-90 had normal concentration distributions in Y and Z directions. The migration rate of the mass center for Sr-90 in X direction was calculated as 3.5 x 10(-5) cm/d, the distribution coefficient for Sr-90 in the aquifer was calculated as 7.4 x 10(2) ml/g and the diffusion coefficient for Sr-90 in the aquifer in X direction was calculated as 1.3 x 10(-11) m(2)/s.