基岩裂隙水中^(90)Sr迁移的数值模拟

Numerical simulation of the ^(90)Sr migration in fissure water

针对我国西北某放射性废物处置场的水文地质情况,通过渗透张量系数计算和溶质迁移参数测试,建立了基岩裂隙水渗透模型和90Sr在基岩裂隙水中的迁移模型。根据以上两个模型的耦合,采用有限差分法,利用MODFLOW软件对90Sr进入处置场地下水后的迁移情况进行了数值模拟预测。计算结果表明,由于机械弥散、对流作用、地质介质的吸附阻滞作用以及核素本身的衰变作用,处置库运行100a后因破坏而导致核素90Sr进入地下水后的有害污染面积比较小,不会对水井及下游造成不利的影响。

Based on hydrogeology of a subterranean disposal place in north-west China and through calculating the infiltration tensor coefficient and testing the parameter of solute migration, the paper have modeled the penetrability of fissure water in bed rock and the ^(90)Sr migration in fissure water. According to the coupling of these two models, a finite difference technique and a modeling code of MOD-(FLOW) are adopted to numerically simulate the ()^(90)Sr migration in fissure water. The numerical simulation result stated that the disposal place would be destroyed after running for 100 a, but the polluted squares had no effect on the well and downriver after ^(90)Sr went into underground because of machine dispersion,convection, and adsorption and retardancy.