Download or read book Three Dimensional Radionuclide Transport Through the Unsaturated Zone of the Yucca Mountain Site 3 Colloids written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors investigated colloid transport in the unsaturated fractured zone by means of three-dimensional site-scale numerical model under present-day climate infiltration, considering varying colloid diameters, kinetic declogging, and filtration. The radionuclide transport model was used to simulate continuous release of colloids into fractures throughout the proposed repository, in which any components of engineered barrier system such as waste package or drip shield were not considered. the results of the study indicate the importance of subsurface geology and site hydrology, i.e., the presence of faults (they dominate and control transport), fractures (the main migration pathways), and the relative distribution of zeolitic and vitric tuffs. The simulations indicate that (1) colloid transport is not significantly affected by varying the filtration parameters, (2) travel time to the water table decreases with the colloid size, (3) larger colloids show little retardation whereas very small ones are retarded significantly, and (4) fracture filtration can have an impact on transport. Because of uncertainties in the fundamentals of colloid transport and an extremely conservative approach (based on an improbably adverse worst-case scenario), caution should be exercised in the analysis and interpretation of the 3-D simulation results. The results discussed here should be viewed as an attempt to identify and evaluate the mechanisms, processes, and geological features that control colloidal transport.

Download or read book RADIONUCLIDE TRANSPORT MODELS UNDER AMBIENT CONDITIONS written by S. Magnuson and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this model report is to document the unsaturated zone (UZ) radionuclide transport model, which evaluates, by means of three-dimensional numerical models, the transport of radioactive solutes and colloids in the UZ, under ambient conditions, from the repository horizon to the water table at Yucca Mountain, Nevada.

Download or read book Preliminary 3 D Site scale Studies of Radioactive Colloid Transortin the Unsaturated Zone at Yucca Mountain Nevada written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S: Department of Energy is actively investigating the technical feasibility of permanent disposal of high-level nuclear waste in a repository to be situated in the unsaturated zone at Yucca Mountain, Nevada. In this study we investigate, by means of numerical simulation, the transport of radioactive colloids under ambient conditions from the potential repository horizon to the water table. The site hydrology and the effects of the spatial distribution of hydraulic and transport properties in the Yucca Mountain subsurface are considered. The study of migration and retardation of colloids accounts for the complex processes in the unsaturated zone of Yucca Mountain, and includes advection, diffusion, hydrodynamic dispersion, kinetic colloid filtration, colloid straining, and radioactive decay. The results of the study indicate that the most important factors affecting colloid transport are the subsurface geology and site hydrology, i.e., the presence of faults (they dominate and control transport), fractures (the main migration pathways), and the relative distribution of zeolitic and vitric tuffs. The transport of colloids is strongly influenced by their size (as it affects diffusion into the matrix, straining at hydrogeologic unit interfaces, and transport velocity) and by the parameters of the kinetic-filtration model used for the simulations. Arrival times at the water table decrease with an increasing colloid size because of smaller diffusion, increased straining, and higher transport velocities. The importance of diffusion as a retardation mechanism increases with a decreasing colloid size, but appears to be minimal in large colloids.

Download or read book Viability Assessment of a Repository at Yucca Mountain License application plan and costs written by and published by . This book was released on 1998 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Yucca Mountain Site Characterization Project Bibliography 1994 1995 written by and published by . This book was released on 1996 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viability Assessment of a Repository at Yucca Mountain Total system performance assessment written by and published by . This book was released on 1998 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viability Assessment of a Repository at Yucca Mountain Introduction and site characteristics written by and published by . This book was released on 1998 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Site Characterization Progress Report written by and published by . This book was released on 1997 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Yucca Mountain Site Characterization Project Bibliography 1992 1993 written by and published by . This book was released on 1994 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Studies of Mountain scale Radionuclide Transport in the Unsaturated Zone at Yucca Mountain Nevada written by and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate radionuclide transport from a high-level nuclear waste repository to be situated in the unsaturated zone (UZ) at Yucca Mountain (YM), Nevada. Several radioactive solutes (that cover the range of sorption behavior) and colloids of various sizes are studied. The results of the study indicate the importance of the subsurface geology and site hydrology, i.e., the presence of faults (they dominate and control transport), fractures (the main migration pathways), and the relative distribution of zeolitic and vitric tuffs. The effects of the climatic conditions, diffusion, and sorption (for solutes) or infiltration (for colloids) onto the matrix are discussed. The influence of the colloid size on transport is also investigated.

Download or read book Hydrology and Geochemistry of Yucca Mountain and Vicinity Southern Nevada and California written by John S. Stuckless and published by Geological Society of America. This book was released on 2012 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Negotiation de la paix de Ryswick ou l an examine les droits et pretentions du Roi de France sur chacun des serenissimes princes alliez et les droits et pretentions des princes alliez sur le Roi de France written by and published by . This book was released on 1697 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Progress Report on Colloid facilitated Transport at Yucca Mountain written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Site Scale Saturated Zone Transport written by S. KELLER. and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work provides a site-scale transport model for calculating radionuclide transport in the saturated zone (SZ) at Yucca Mountain, for use in the abstractions model in support of ''Total System Performance Assessment for License Application'' (TSPA-LA). The purpose of this model report is to provide documentation for the components of the site-scale SZ transport model in accordance with administrative procedure AP-SIII. 10Q, Models. The initial documentation of this model report was conducted under the ''Technical Work Plan For: Saturated Zone Flow and Transport Modeling and Testing'' (BSC 2003 [DIRS 163965]). The model report has been revised in accordance with the ''Technical Work Plan For: Natural System--Saturated Zone Analysis and Model Report Integration'', Section 2.1.1.4 (BSC 2004 [DIRS 171421]) to incorporate Regulatory Integration Team comments. All activities listed in the technical work plan that are appropriate to the transport model are documented in this report and are described in Section 2.1.1.4 (BSC 2004 [DIRS 171421]). This report documents: (1) the advection-dispersion transport model including matrix diffusion (Sections 6.3 and 6.4); (2) a description and validation of the transport model (Sections 6.3 and 7); (3) the numerical methods for simulating radionuclide transport (Section 6.4); (4) the parameters (sorption coefficient, Kd) and their uncertainty distributions used for modeling radionuclide sorption (Appendices A and C); (5) the parameters used for modeling colloid-facilitated radionuclide transport (Table 4-1, Section 6.4.2.6, and Appendix B); and (6) alternative conceptual models and their dispositions (Section 6.6). The intended use of this model is to simulate transport in saturated fractured porous rock (double porosity) and alluvium. The particle-tracking method of simulating radionuclide transport is incorporated in the finite-volume heat and mass transfer numerical analysis (FEHM) computer code, (FEHM V2.20, STN: 10086-2.20-00) (LANL 2003 [DIRS 161725]) and is described in Section 6.4 of this report. FEHM is a three-dimensional (3-D), finite-volume, finite-element, heat and mass flow-and-transport code. This report documents the features and capabilities of the site-scale transport model for calculating radionuclide transport in the SZ at Yucca Mountain in support of the TSPA-LA. Correlative flow-model calculations using FEHM are carried out and documented in the model report ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]). The velocity fields are calculated by the flow model independent of the transport processes and supplied as a part of the output package from the flow model, which is then used as inputs to the transport model. Several SZ analysis model reports provide information and data needed as feed-ins for this report, and this report in turn provides technical product outputs that feed into other SZ reports. The details of inputs to the site-scale transport model are provided in Section 4.

Download or read book Colloid and Colloid Facilitated Contaminant Transport Experiments and Models to Support Assessments of Radionuclide Migration at Yucca Mountain and the Nevada Test Site written by P. Reimus and published by . This book was released on 2004 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, numerous laboratory and field experiments have been conducted to assess and parameterize colloid and colloid-facilitated radionuclide transport for the Yucca Mountain Project and the Nevada Test Site (NTS) Environmental Restoration Project. Radionuclide contamination of ground water currently exists within or near underground nuclear test cavities at the NTS, and the proposed Yucca Mountain high-level nuclear waste repository represents a potential future source of radionuclide contamination of ground water at the NTS. Furthermore, recent field observations have indicated that small amounts of Plutonium, which normally adsorbs very strongly to mineral surfaces in aquifers, can transport quite rapidly and over significant distances in ground water when associated with inorganic colloids (Kersting et al., 1999). Groundwater samples from all over the Nevada Test Site have been analyzed for colloid concentrations and size distributions, and it is clear that there are significant mass loadings of colloids in the ground water at some locations. These colloids represent mobile surface area for potentially transporting strongly-adsorbed radionuclides. Field transport experiments have involved the use of fluorescent-dyed carboxylate-modified latex (CML) microspheres in the 250- to 650-nm diameter size range as surrogates for natural colloids in forced-gradient tracer tests. These experiments have indicated that effective colloid filtration coefficients appear to decrease as time and length scales increase. They suggest that a small fraction of colloids may be able to transport significant distances in groundwater systems. Laboratory experiments have been conducted to determine radionuclide sorption and desorption parameters onto inorganic colloids present in the groundwater systems and also to determine transport parameters for inorganic colloids in both fractured and porous media present at the Nevada Test Site. More recent laboratory experiments have involved injecting inorganic colloids with radionuclides adsorbed onto them into fractured or porous media to determine the ability of the colloids to facilitate the transport of the radionuclides through the media. Recent experiments have also involved comparing the transport behavior of CML microspheres and inorganic colloids so that more defensible inferences about inorganic colloid transport can be made from CML microsphere transport observations in field tracer tests. All of this experimental information has been collectively used to develop a modeling framework for evaluating sensitivities of predicted colloid-facilitated radionuclide transport to various colloid-transport and radionuclide-colloid-interaction parameters. This modeling framework is helping to focus future experimental efforts on processes and parameters that have the greatest potential impact on colloid-facilitated radionuclide transport at the Nevada Test Site.

Download or read book Colloid facilitated Radionuclide Transport at Yucca Mountain written by Ines R. Triay and published by . This book was released on 1995 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Final Environmental Impact Statement for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High level Radioactive Waste at Yucca Mountain Nye County Nevada Appendixes A through O written by and published by . This book was released on 2002 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this environmental impact statement (EIS) is to provide information on potential environmental impacts that could result from a Proposed Action to construct, operate and monitor, and eventually close a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste at the Yucca Mountain site in Nye County, Nevada. The EIS also provides information on potential environmental impacts from an alternative referred to as the No-Action Alternative, under which there would be no development of a geologic repository at Yucca Mountain.