Author(s): Teruyuki Fukuhara; Kuniaki Sato
Linked Author(s): Kuniaki Sato
Keywords: Heat and mass transfer; Radioactive nuclides; Groundwater; Condensation; Evaporation
Abstract: The possibility of condensation of nuclides in an underground disposal of the low-level radioactive waste is examined from the theory on the heat, mass and solute transfer with the evaporation. Since the interactions between the soil surface and the atmosphere have direct impacts on the condensation and upward migration of nuclides, mathematical treatments of heat energy, moisture and solute fluxes at the soil surface are presented in this paper. The solute transfer equation includes the condensation term due to the evaporation and the mathematical model on the heat and moisture transfer through soil layers follows the theory developed by Philip and de Vries (1957). Comparison with experimental results of Sato, et al. (1989) shows the accuracy of the proposed mathem atical model. Numerical computations reasonably explain the condensation of solutes (Na Cl, Sr and Co) at the soil surface obtained experim entally. Finally, a practical example of the underground disposal yard of low-level radioactive waste is assumed and the hazard of condensation and upward migration of nuclides due to the rainfall-evaporation cycles is estimated.
Year: 1993