内陆核电站事故情况下核素迁移扩散模拟

Simulation of radionuclide diffusion of an inland nuclear power plant under accident condition

针对某拟建内陆核电站,选择二维数值模型,运用Fluent软件模拟了受纳水体的流场及假想事故情况下放射性液态流出物的稀释扩散情况.模拟结果显示:模拟的流场基本能够反映受纳水域实际情况,短半衰期核素131I比长半衰期核素137 Cs浓度下降更快,且两者都有向上游以及泄漏点下游各支流有限扩散的趋势,流速相对较小或者存在涡流的库汊和库湾容易造成核素的长期滞留,假想事故下的污染物影响会持续50d以上.

An proposed inland nuclear power plant was taken as research object , two-dimensional model and FLUENT software were used to simulate the flow field of receiving water and radionuclide diffusion of radioactive liquid effluent in accident condition .The result of simulation shows that it could reflect the real flow field basically .Short half-life nuclide 131 I has faster speed of concentration decreasing than long half-life nuclide 137 Cs ,but they both have a trend to diffuse into upstream and the tributaries of the lower river .In the area where flow velocity is relatively slow ,the radionuclides will stay longer term .For the whole reservoir ,radioactive contaminant will last more than 50 d in the hy-pothetical accident condition .