This study predicted temperature in the disposal tunnels using computational fluid dynamics based on natural ventilation quantity that comes from high altitude and temperature differences that are the characteristics of high level waste repository. The result of the previous study that evaluated quantitatively natural ventilation quantity using a hydrostatic method and CFD shows that significant natural ventilation quantity is generated. From the result, this study performed the prediction of temperature in disposal tunnels by natural ventilation quantity by the caloric values of the wastes, at both deep geological repository and surface repository. The result of analysis shows that deep geological repository is effective for thermal control in the disposal tunnels due to heat transfer to rock and the generation of sufficient natural ventilation quantity, while surface repository was detrimental to thermal control, because surface repository was strongly affected by external temperature, and could not generate sufficient natural ventilation quantity. Moreover, this study found that in the case of deep geological repository with a depth of 200 m, the heatof about 10℃ was transferred to the depth of 500 m. Thus, it is considered that if the high level waste repository scheduled to be built in the country is designed placing an emphasis on thermal control, deep geological repository rather than surface repository is more appropriate.

For this research, a coal mine was examined that has the deepest coal mining activities in the country, in order to improve hot and humid work environment. The Ventsim 3D program was used for a simulation of ventilation network and temperature analysis. Ventilation network modeling was set up that reflected natural ventilation. Natural ventilation pressure formed between No.1 shaft and No.2 shaft, and it was calculated to be approximately 245 Pa. Based on the completed ventilation modeling, a simulation of increased ventilation was done, assuming the extension of shaft and the installation of mine doors. The simulation result showed an increased air inflow over 50% in deep mines. However, it did not affect the temperature environment of the deeper part of the mine. To improve hot and humid work environment, temperature simulation was carried out, reflecting the operation of the air cooler. According to the simulation result, it was deemed that three additional air coolers need to be installed to create the work environment with the WBGT between 25.0℃ and 27.9℃. And the length of mine duct should not exceed the maximum 800 m.

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