干旱区生态环境知识资源中心(Arid): Predicting long-term moisture contents of earthen covers at uranium mill tailings sites

Arid

DOI	10.2172/6432626
报告编号	DOE/UMT-0220; PNL-5047
来源ID	OSTI_ID: 6432626
	Predicting long-term moisture contents of earthen covers at uranium mill tailings sites
	Gee, G.W.; Nielson, K.K.; Rogers, V.C.
英文摘要	The three methods for long-term moisture prediction covered in this report are: estimates from water retention (permanent wilting point) data, correlation with climate and soil type, and detailed model simulation. The test results have shown: soils vary greatly in residual moisture. Expected long-term moisture saturation ratios (based on generalized soil characteristics) range from 0.2 to 0.8 for soils ranging in texture from sand to clay, respectively. These values hold for noncompacted field soils. Measured radon diffusion coefficients for soils at 15-bar water contents ranged from 5.0E-2 cm/sup 2//s to 5.0E-3 cm/sup 2//s for sands and clays, respectively, at typical field densities. In contrast, fine-textured pit-run earthen materials, subjected to optimum compaction (>85% Proctor density) and dried to the 15-bar water content, ranged from 0.7 to 0.9 moisture saturation. Compacted pit-run soils at these moisture contents exhibited radon diffusion coefficients as low as 3.0E-4 cm/sup 2//s. The residual moisture saturation for cover soils is not known since no engineered barrier has been in place for more than a few years. A comparison of methods for predicting moisture saturation indicates that model simulations are useful for predicting effects of climatic changes on residual soil moisture, but that long-term moisture also can be predicted with some degree of confidence using generalized soil properties or empirical correlations based both on soils and climatic information. The optimal soil cover design will likely include more than one layer of soil. A two-layer system using a thick (1-m minimum) plant root zone of uncompacted soil placed over a moistened, tightly compacted fine-textured soil is recommended. This design concept has been tested successfully at the Grand Junction, Colorado, tailings piles.
出版年	1984
报告类型	Technical Report
语种	英语
国家	美国
来源学科分类	11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS ; 12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES ; COVERINGS ; MOISTURE ; MILL TAILINGS ; COMPACTING ; DIFFUSION ; RADON 222 ; SOILS ; THICKNESS ; ALPHA DECAY RADIOISOTOPES ; DAYS LIVING RADIOISOTOPES ; DIMENSIONS ; EVEN-EVEN NUCLEI ; HEAVY NUCLEI ; ISOTOPES ; NUCLEI ; RADIOISOTOPES ; RADON ISOTOPES ; SOLID WASTES ; TAILINGS ; WASTES 054000* -- Nuclear Fuels-- Health & Safety ; 053000 -- Nuclear Fuels-- Environmental Aspects ; 052002 -- Nuclear Fuels-- Waste Disposal & Storage
URL	http://www.osti.gov/scitech/servlets/purl/6432626
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/263641
推荐引用方式 GB/T 7714	Gee, G.W.,Nielson, K.K.,Rogers, V.C.. Predicting long-term moisture contents of earthen covers at uranium mill tailings sites,1984.