A Very Low In The Southwest Mountain To Put The Waste Disposal Site No. ¢ñ Site Groundwater Environmental Impact Assessment

The environmental impact assessment of nuclear waste disposal site in groundwater is a focal point in the course of disposing radioactive waste, and it also is one of the key problems about security evaluation of waste disposal field. A very important content of environmental assessment is to appraise the effect degree for human since the radionuclide release from the waste warehouse and migrate with medium in groundwater. In our country, the environmental assessment in groundwater is restricted with the fund, the time limit, people's understanding and difficulty, etc. The assessment is a quite hardness. The nuclear waste once enters in the groundwater, will be able to cause the groundwater to be polluted, destroy the ecological environment, and harm the human body health.The research area lies in the northwest edge of Sichuan basin. One retired nucleus project produce the massive nuclear waste (VLLW), needed to handle nearby in this region .According to the IAEA suggestion and national experience, this kind of waste must choose the suitable field to dispose.The paper chooses a nuclear waste disposal No. 1 site in southwest- mountainous area as research object. On the base of geologic environmental investigation, the environmental impact assessment is to appraise the modality and route of radio nuclide in groundwater after the disposal site working.According to the scene investigation and exploration, the paper has analyzed geologic and the hydro-geological conditions in the disposal site area, and used two methods: the environmental capacity analysis and numerical simulation to forecast the local groundwater and the rivers pollution degree if the nuclide divulges from the disposal storehouse.Based on 3-group solute migration tracer tests, the results show that advection-dispersion function is restricted with groundwater dominance flown line, and only limits to one range in layer. The environmental capacity analysis method applies this rule to the research field, and makes the preliminary forecast to the nuclide influence scope. The numerical simulation uses MODFLOW and MT3DMS software to simulation the nuclide migration in aquifer on the base of finding...