부산대학교 도서관

Cyclical variations in barometric pressure cause an oscillatory up-and-down motion of gases within the chimney produced by an underground nuclear test. Analytical and experimental modeling of this atmospheric pumping mechanism has been undertaken to better understand and to quantify the associated rates of cavity gas migration toward the earth's surface and the probable rate of release to the atmosphere. Three different types of models are being investigated: (1) homogeneous porous medium; (2) fractured medium with impermeable matrix blocks; and (3) double-porosity media consisting of fracture networks among porous matrix blocks. A primary purpose is to understand how the oscillatory character of the atmospheric pumping process might significantly enhance the contaminant transport in any or all of the three classes of media. This preliminary report describes some of the analytical, numerical, and experimental work which have been completed.