Investigation Research on the Evaluation of a Coupled Thermo-Hydro-Mechanical-Chemical Phenomena (III) -Result Report-

Ishihara, Yoshinao*; Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Shiozaki, Isao*; Ito, Takaya*

JNC TJ8400 2004-004, 625 Pages, 2004/02

JNC-TJ8400-2004-004.pdf:7.37MB

In order to realize a coupling analysis in the near field of the geological disposal system, the coupling analysis code on the thermo-hydro-mechanical-chemical phenomena by THAMES, Dtransu and phreeqc, which are existing analysis code, is developed in this study. And we carried out the case analysis on the thermo-hydro-mechanical-chemical phenomena by this code.(1).Some supporting module, which includes transfer of dissolution concentration and total concentration (dissolution + precipitation concentration), was prepared as a functional expansion. And in order to treat de-gases and gases diffusion, accumulation and dilution phenomena, we have modified mass transport analysis code.(2).We have modified reactive transport module to treat ionic exchange, surface reaction and kinetic reaction in the each barrier.(3).We have prepared hydraulic conductivity module of buffer material depending on change of dry density due to chemical equilibrium (dissolution and precipitation of minerals), degradation of buffer material such as Ca-type bentonite and change of concentration of NaCl solutions. After THAMES, Dtransu, phreeqc and hydraulic conductivity module were installed in the COUPLYS, verification study was carried out to check basic function. And we have modified COUPLYS to control coupling process.(4).In order to confirm the applicability of the developed THMC analysis code, we have carried out case analysis on 1-dimensional and 3-dimensional model which including vitrified waste, over-pack, buffer material and rock in the HLW near-field.