飽和砂層内における放射性核種の 挙動に関する研究(I) : 底質砂層内におけるイオンの拡散係数について

Abstract

Recently, the pollution of water and soil due to industrial or radioactive wastes has been discussed, and it becomes important to forecast the behavior of pollutants in environmental hydro-system, such as substratum layer near the coast of nuclear power plant site. The degree of mobility of radionuclides can be represented by the apparent diffusion coefficients in a bottom layer. So, these work presented a mathematical model with non-steady boundary condition which could determine this coefficients, and examined the validity of this model by laboratory experiments, where many long-lived radionuclides diffused into a sandy sediment. The values of apparent diffusion coefficient were approximately obtained as follows, (3-4)X10-7cm2/sec for Sr, (1-2)X10-7cm2/sec for Mn and (3-8)X10-8cm2/sec for Cd, Co and Zn. The theoretical models for Ru, Ce, Hg and Zr were not suited for description of their behavior owing to the complex sorption model.