高放废物处置库近场裂隙水流-传热-处置室间距相互作用的三维数值分析

为研究高放废物地质处置库近场裂隙水流-传热-处置室间距的相互作用机理,采用3DEC软件计算裂隙水流-传热-处置室间距相互作用对处置库近场温度分布影响。结果表明:(1)在处置室间距相同条件下,流动的裂隙水显著改变了处置库近场温度场,使岩体温度降低,缩短模型达到稳态所需要的时间。(2)处置室间距增大,温度叠加效应减弱,处置库近场温度越低,并且废物罐表面膨润土温度越低,裂隙出水口水温越低,模型达到稳态所需要的时间越短。(3)水平和垂直裂隙水流共同传热使处置库近场裂隙水流下游区域温度显著高于裂隙水流上游区域。(4)处置室间距为6 m和8 m时,水平裂隙出水口水温高于垂直裂隙,处置室间距为10 m时,水平裂隙出水口水温低于垂直裂隙。

Three-dimensional numerical analysis of the interaction between fracture water flow,heat transfer and distance between disposal pits in the near field of high-level radioactive waste repository

In order to study the interaction mechanism between fracture water flow, heat transfer and distance between disposal pits in the near field of high-level radioactive waste repository, 3DEC software is used to calculate the influence of the interaction of fracture water flow, heat transfer and distance between disposal pits on the near-field temperature distribution of the disposal repository. Results show that: (1) Under the same disposal pit spacing, the flowing fracture water changes the temperature field near the disposal pit, decreases the rock mass temperature, and obviously shortens the time required for the model to reach steady state; (2) The larger the distance between the disposal pits, the weaker the temperature superposition effect. The lower the near-field temperature of the disposal repository, the lower the temperature of bentonite of waste tank surface. The lower the water temperature at the outlet of the fracture, the shorter the time required for the model to reach a steady state; (3) The temperature in downstream area of near-field fracture water flow is significantly higher than that in upstream area of fracture water flow in the disposal reservoir due to joint heat transfer between horizontal and vertical fracture water flows; (4) The water temperature of horizontal fracture water outlet is higher than that of the vertical fracture water outlet when the spacing of the disposal pit is 6 m and 8 m, but the water temperature of the horizontal fracture water outlet is lower than that of the vertical fracture water outlet when the spacing of the disposal pit is 10 m.