Radionuclide Migration Through Fractured Rock: Effects of Multiple Fractures and Two-Member Decay Chains

摘要

This report presents the results of an analytical study of the hydrological transport of a radioactive contaminant through fractured, porous rock. The purpose is to evaluate the time-, and space-dependent concentration of the contaminant in the ground-water in the fractures and in the rock pores. We propose a simplified analytical method that superposes two single-fracture solutions for the concentration in the rock matrix with a system of parallel fractures. The exact solutions require multiple integrals and summation of an infinite series, which converges slowly because of its oscillating nature. The convergence of the series becomes slower for strongly-sorbing media, large spacing of two fractures, and early times. In summary, we made extension to the theory of radionuclide penetration into multiply fractured rock, and provided solutions for a two-member decay chain. 9 refs., 10 figs., 1 tab. (ERA citation 13:014313)