Research On The Influence Of Severe Nuclear Accidents On Groundwater And Emergency Countermeasures

As a kind of clean energy,nuclear power has been paid more and more attention and developed.At the same time,nuclear safety has become a key issue in the development of nuclear power,especially the impact of sudden nuclear accident on water resources has aroused widespread concern.The impact of sudden nuclear accident on water resources includes the impact on surface water and groundwater,and the impact on groundwater should be taken more seriously because of the long duration and the difficulty of treatment.Taking an inland nuclear power plant as a typical case,in consideration of the effect of aeration zone,nuclide decay and adsorption,this paper calculates the groundwater flow and nuclide spatial and temporal distribution under the accident conditions,proposes some emergency measures that can be taken after the accident,and formulated emergency plans for groundwater resources.The main research content is as follows:(1)Taking the Taohuajiang Nuclear Power Station as a typical case,combined with the hydrogeological and engineering geological data of the surrounding area of the power station,under the influence of the unsaturated zone and the saturated zone,the groundwater flow field in the study area and the buried depth of the aerated zone were analyzed and calculated.(2)According to the way that the nuclide may enter the groundwater,three working conditions-point source,surface source and line source-are set up to study the impact of serious nuclear accidents on groundwater.Research indicates that the possibility of the radioactive nuclide directly enters the groundwater on large scale can be eliminated under point source conditions,and only the earthworms will have a slight influence on the groundwater.Under the condition of line source,the scope of diffusion of contaminated groundwater via surface water is also limited.Under surface source conditions,the condition that the radionuclides penetrate into the groundwater passing through the aeration zone after wet deposition will cause a long time impact on the groundwater around the nuclear power plant,and relevant measures should be taken.In summary,due to the delay and adsorption of the vadose zone,the overall impact on groundwater during the occurrence of a serious nuclear accident at the Taohuajiang Nuclear Power Station is not significant.(3)Based on the transport laws and calculations of radionuclides in groundwater,and combining the research on nuclear power plants and nuclear accident emergency response at home and abroad,three aspects---source control,near-field blocking,and far-field protection----were proposed to mitigate the impact on groundwater after the accident occurred.Also an emergency plan for protecting groundwater resources are formulated.