Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations

doi:10.2172/1167312

GSTDTAP > 地球科学

DOI	10.2172/1167312
报告编号	PNNL--23841
来源ID	OSTI ID: 1167312
	Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations
	Golovich, Elizabeth C.; Mattigod, Shas V.; Snyder, Michelle MV
	2014-11-01
出版年	2014
页数	226
语种	英语
国家	美国
领域	地球科学
英文摘要	The Waste Management Project provides safe, compliant, and cost-effective waste management services for the Hanford Site and the U.S. Department of Energy (DOE) complex. Part of these services includes safe disposal of low-level waste and mixed low-level waste at the Hanford Low-Level Waste Burial Grounds in accordance with the requirements of DOE Order 435.1, Radioactive Waste Management. To partially satisfy these requirements, performance assessment analyses were completed and approved. DOE Order 435.1 also requires continuing data collection to increase confidence in the critical assumptions used in these analyses to characterize the operational features of the disposal facility that are relied on to satisfy the performance objectives identified in the order. Cement-based solidification and stabilization is considered for hazardous waste disposal because it is easily done and cost-efficient. One critical assumption is that concrete will be used as a waste form or container material at the Hanford Site to control and minimize the release of radionuclide constituents in waste into the surrounding environment. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The radionuclides iodine-129, selenium-75, technetium-99, and uranium-238 have been identified as long-term dose contributors (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, these constituents of potential concern may be released from the encased concrete by mass flow and/or diffusion and migrate into the surrounding subsurface environment (Serne et al. 1989; 1992; 1993a, b; 1995). Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. Each of the test methods performed throughout the lifetime of the project has focused on different aspects of the concrete waste form weathering process. Diffusion of different analytes [technetium-99 (Tc-99), iodine-125 (I-125), stable iodine (I), uranium (U), and rhenium (Re)] has been quantified from experiments under both saturated and unsaturated conditions. The water-saturated conditions provide a conservative estimate of the concreteâs performance in situ, and the unsaturated conditions provide a more accurate estimate of the diffusion of contaminants from the concrete.
英文关键词	concrete radonuclide diffusion saturated unsaturated
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来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/6673
专题	地球科学
推荐引用方式 GB/T 7714	Golovich, Elizabeth C.,Mattigod, Shas V.,Snyder, Michelle MV. Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations,2014.