Transport of radon from fractured rock
Transport of radon from fractured rock
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DOI：
10.1029/jb087ib04p02969
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发表时间：
1982-04
影响因子：
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通讯作者：
S. Schery;D. Gaeddert;M. Wilkening
中科院分区：
文献类型：
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作者：
S. Schery;D. Gaeddert;M. Wilkening
在某废弃矿山，研究了裂隙岩中~(222)Rn的迁移。压力诱导流动(自然和人工)是非常重要的，与自由扩散相比，压力诱导流动很容易导致进入隧道空域的氡的瞬时传输增加一个数量级。渗透率研究表明，表面密度在每平方米数个数量级的大型裂隙在渗流中占主导地位。在一阶中，由自然压力变化引起的有效通量服从近似的dp/dt关系。在较高的阶次，由于自然气压的变化，时间平均通量通常会增加2倍。数学模拟表明，对于半无限均匀多孔介质，压力与氡运移强度和时间的关系很难单独用常规模型来解释。提出了一个死胡同小室模型来解释这种依赖关系。
The transport of 222Rn from fractured rock has been studied in an abandoned mine. Pressure-induced flow (both natural and artificial) is quite important and can easily cause an order of magnitude increase in the instantaneous transport of radon into the tunnel airspace compared to that due to flowfree diffusion. Permeability studies indicate that large-scale cracks of surface density of the order of several cracks per square meter dominate flow. In first order, effective flux due to natural pressure variation follows an approximate dP/dt dependence. In higher order, there exists an enhancement of time-averaged flux by typically a factor of 2 due to natural pressure variation. Mathematical modeling indicates that the relation between pressure and the strength and time dependence of the radon transport is difficult to explain solely with conventional models for semi-infinite homogeneous porous media. A model of cul-de-sac chambers is proposed to account for some of this dependence.