科技报告详细信息
Analysis of Fracture in Cores from the Tuff Confining Unit beneath Yucca Flat, Nevada Test Site | |
Lance Prothro | |
关键词: APERTURES; CARBONATES; DENSITY; FRACTURES; HYDRAULICS; MINERALS; NEVADA TEST SITE; OPENINGS; RADIOISOTOPES; TESTING; TUFF; UNDERGROUND; VOLUME; ZEOLITES tuff confining unit; fracture characteristics; Nevada Test Site; UGTA; | |
DOI : 10.2172/928855 RP-ID : DOE/NV/25946--351 PID : OSTI ID: 928855 Others : TRN: US200822%%965 |
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美国|英语 | |
来源: SciTech Connect | |
【 摘 要 】
The role fractures play in the movement of groundwater through zeolitic tuffs that form the tuff confining unit (TCU) beneath Yucca Flat, Nevada Test Site, is poorly known. This is an important uncertainty, because beneath most of Yucca Flat the TCU lies between the sources of radionuclide contaminants produced by historic underground nuclear testing and the regional carbonate aquifer. To gain a better understanding of the role fractures play in the movement of groundwater and radionuclides through the TCU beneath Yucca Flat, a fracture analysis focusing on hydraulic properties was performed on conventional cores from four vertical exploratory holes in Area 7 of Yucca Flat that fully penetrate the TCU. The results of this study indicate that the TCU is poorly fractured. Fracture density for all fractures is 0.27 fractures per vertical meter of core. For open fractures, or those observed to have some aperture, the density is only 0.06 fractures per vertical meter of core. Open fractures are characterized by apertures ranging from 0.1 to 10 millimeter, and averaging 1.1 millimeter. Aperture typically occurs as small isolated openings along the fracture, accounting for only 10 percent of the fracture volume, the rest being completely healed by secondary minerals. Zeolite is the most common secondary mineral occurring in 48 percent of the fractures observed.【 预 览 】
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RO201705180002447LZ | 15116KB | download |