Download or read book Waste Form and Indrift Colloids Associated Radionuclide Concentrations written by R. Aguilar and published by . This book was released on 2003 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Model Report describes the analysis and abstractions of the colloids process model for the waste form and engineered barrier system components of the total system performance assessment calculations to be performed with the Total System Performance Assessment-License Application model. Included in this report is a description of (1) the types and concentrations of colloids that could be generated in the waste package from degradation of waste forms and the corrosion of the waste package materials, (2) types and concentrations of colloids produced from the steel components of the repository and their potential role in radionuclide transport, and (3) types and concentrations of colloids present in natural waters in the vicinity of Yucca Mountain. Additionally, attachment/detachment characteristics and mechanisms of colloids anticipated in the repository are addressed and discussed. The abstraction of the process model is intended to capture the most important characteristics of radionuclide-colloid behavior for use in predicting the potential impact of colloid-facilitated radionuclide transport on repository performance.
Download or read book Colloid Associated Radionuclide Concentration Limits written by and published by . This book was released on 2000 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose and scope of this report is to describe the analysis of available colloidal data from waste form corrosion tests at Argonne National Laboratory (ANL) to extract characteristics of these colloids that can be used in modeling their contribution to the source term for sparingly soluble radioelements (e.g., Pu). Specifically, the focus is on developing a useful description of the following waste form colloid characteristics: (1) composition, (2) size distribution, and (3) quantification of the rate of waste form colloid generation. The composition and size distribution information are intended to support analysis of the potential transport of the sparingly soluble radionuclides associated with the waste form colloids. The rate of colloid generation is intended to support analysis of the waste form colloid-associated radionuclide concentrations. In addressing the above characteristics, available data are interpreted to address mechanisms controlling colloid formation and stability. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M & O 2000). Because the end objective is to support the source term modeling we have organized the conclusions into two categories: (1) data analysis conclusions and (2) recommendations for colloid source term modeling. The second category is included to facilitate use of the conclusions from the data analysis in the abstraction of a colloid source term model. The data analyses and conclusions that are presented in this report are based on small-scale laboratory tests conducted on a limited number of waste glass compositions and spent fuel types.
Download or read book Colloid nanoparticle formation and mobility in the context of deep geological nuclear waste disposal Project KOLLORADO 2 final report written by Huber, Florian and published by KIT Scientific Publishing. This book was released on 2014-03-03 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: To assess the relevance of colloidal influences on radionuclide transport for the long-term safety of a radioactive waste repository, the KOLLORADO-2 project integrates the results of geochemical and hydrogeological studies. The results may serve as a basis for an appraisal of the implications of colloid presence in the vicinity of radioactive waste repositories in different deep geological host-rock formations.
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 The Role of Colloids and Suspended Particles in Radionuclide Transport in the Canadian Concept for Nuclear Fuel Waste Disposal written by Peter Vilks and published by Pinewa, Man. : Whiteshell Laboratories. This book was released on 1994 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: AECL Research is developing a concept for the permanent disposal of nuclear fuel waste in a deep engineered vault in plutonic rock of the Canadian Shield and is preparing an environmental impact statement (EIS) to document its case for the acceptability of the disposal concept. This report addresses the role of particles in radionuclide transport. It summarizes studies of natural particles in groundwater and presents the arguments used to justify the omission of particle-facilitated transport in the geosphere model that is based on the Whiteshell Research Area and used in the postclosure assessment study case.
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 The role of colloids in the release of radionuclides from nuclear waste written by J.D.F. Ramsay and published by . This book was released on 1985 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book De Minimus written by Nuclear Safety Associates and published by . This book was released on 1978 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book IGNEOUS INTRUSION IMPACTS ON WASTE PACKAGES AND WASTE FORMS written by P. Bernot 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 assess the potential impacts of igneous intrusion on waste packages and waste forms in the emplacement drifts at the Yucca Mountain Repository. The models are based on conceptual models and includes an assessment of deleterious dynamic, thermal, hydrologic, and chemical impacts. The models described in this report constitute the waste package and waste form impacts submodel of the Total System Performance Assessment for the License Application (TSPA-LA) model assessing the impacts of a hypothetical igneous intrusion event on the repository total system performance. This submodel is carried out in accordance with Technical Work Plan for Waste Form Degradation Modeling, Testing, and Analyses in Support of LA (BSC 2004 [DIRS:167796]) and Total System Performance Assessment-License Application Methods and Approaches (BSC 2003 [DIRS: 166296]). The technical work plan was prepared in accordance with AP-2.27Q, Planning for Science Activities. Any deviations from the technical work plan are documented in the following sections as they occur. The TSPA-LA approach to implementing the models for waste package and waste form response during igneous intrusion is based on identification of damage zones. Zone 1 includes all emplacement drifts intruded by the basalt dike, and Zone 2 includes all other emplacement drifts in the repository that are not in Zone 1. This model report will document the following model assessments: (1) Mechanical and thermal impacts of basalt magma intrusion on the invert, waste packages and waste forms of the intersected emplacement drifts of Zone 1. (2) Temperature and pressure trends of basaltic magma intrusion intersecting Zone 1 and their potential effects on waste packages and waste forms in Zone 2 emplacement drifts. (3) Deleterious volatile gases, exsolving from the intruded basalt magma and their potential effects on waste packages of Zone 2 emplacement drifts. (4) Post-intrusive physical-chemical environment and seepage water alteration by reaction with intruded basalt. The scope of this model only includes impacts to the components stated above, and does not include impacts to other engineered barrier system (EBS) components such as the waste package pallet. The results of this model report will be used in TSPA for several parameters including (1) temperature of magma (used for the temperature of the waste form after an intrusion) (2) temperature increase in Zone 2 due to intrusion to evaluate impact to Zone 2 waste packages; (3) effects of exsolved gases reaching Zone 2 to evaluate impact to Zone 2 waste packages; and (4) pH and ionic strength of water reacted with basalt to be used in conjunction with ''Dissolved Concentration Limits of Radioactive Elements'' (BSC 2003 [DIRS: 163152]) to determine solubility of spent fuel within the basalt. Ionic strength will also be used in conjunction with ''Waste Form and In-Drift Colloids-Associated Radionuclide Concentrations: Abstraction and Summary'' (BSC 2003 [DIRS: 166845]) for stability of colloids.
Download or read book The role of colloids in the transport of radionuclides from a radioactive waste repository written by M.P. Gardiner and published by . This book was released on 2001 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Colloids Related to Low Level and Intermediate Level Waste written by J. D. F. Ramsay and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Colloid Facilitated Transport of Radionuclides Through the Vadose Zone written by John F. McCarthy and published by . This book was released on 2006 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main purpose of this project was to advance the basic scientific understanding of colloid and colloid-facilitated Cs transport of radionuclides in the vadose zone. We focused our research on the hydrological and geochemical conditions beneath the leaking waste tanks at the USDOE Hanford reservation. Specific objectives were (1) to determine the lability and thermodynamic stability of colloidal materials, which form after reacting Hanford sediments with simulated Hanford Tank Waste, (2) to characterize the interactions between colloidal particles and contaminants, i.e., Cs and Eu, (3) to determine the potential of Hanford sediments for \textit{in situ} mobilization of colloids, (4) to evaluate colloid-facilitated radionuclide transport through sediments under unsaturated flow, (5) to implement colloid-facilitated contaminant transport mechanisms into a transport model, and (6) to improve conceptual characterization of colloid-contaminant-soil interactions and colloid-facili\-tated transport for clean-up procedures and long-term risk assessment. We have previously shown that upon contact with simulated waste tank solutions, Hanford sediments change their mineralogical composition. Certain minerals, i.e., quartz, smectite, and kaolinite, are partially dissolved, and new mineral phases, i.e., the feldspathoids cancrinite and sodalite, are formed. We have characterized these mineral transformations and clarified the mineral transformation pathways. The new minerals were mainly in the colloidal size fraction (diameter less than 2 mum), had a negative surface charge, and were microporous, meaning they contained small pores. When Cs was present during the formation of the minerals, contaminants, like Cs, could be trapped inside the mineral structure. Transport experiments under water saturated and unsaturated conditions showed that the colloids were mobile in Hanford sediments. As the water saturation of the sediments decreased, the amount of colloids transported also decreased. The colloids had the ability to enhance the migration of the radionuclide Cs; however, Cs initially sorbed to colloids was desorbed during transport through uncontaminated Hanford sediments. The finding that Cs was stripped off the colloids during the transport through uncontaminated sediments implies that colloids will likely not be an effective carrier for Cs, unless the Cs is incorporated into the mineral structure of the colloids such that the radionuclide cannot desorb from the colloids. Nevertheless, it appears that the amount of Cs that can be transported by mobile colloids beneath Hanford waste tanks is limited. Colloids will not be able to move the bulk mass of Cs through the vadose zone at Hanford. Colloid stability studies indicate that Hanford sediment form stable colloidal suspensions when suspended in Hanford sediment pore waters. Colloid stability was assessed by determination of the critical coagulation concentration, i.e., the chemical electrolyte concentration at which colloidal suspensions flocculate and settle out (become unstable). Although in the stable mode, Hanford colloids will settle out of solution after extended periods of time (months to years). Given the low recharge rates at Hanford range, which from near 0 to more than 100 mm/year, and the long travel times for rainwater to reach the groundwater of more than 40 years, it appears that colloidal transport is unlikely to occur if colloids are initially to be suspended close to the soil surface by infiltrating rainwater. However, if preferential flow or transient flow occurs, then colloidal transport may become more important. The results of this project have also led to improvements of our fundamental understanding of colloid transport and mobilization under unsaturated flow conditions in porous media. We have found that colloid attachment to the liquid-gas interface is not that relevant and that colloids rather attached near the triple phase interface where air, water, and solid phases meet. We have also found that capillary forces are the most dominant forces governing colloid release in unsaturated porous media. These results help to advance our understanding of colloid fate and transport in unsaturated porous media.
Download or read book Colloid Formation During Waste Glass Corrosion written by and published by . This book was released on 1996 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long-term behavior of nuclear waste glass in a geologic repository may require a technical consideration of the role of colloids in the release and transport of radionuclides. The neglect of colloidal properties in assessing the near- and far-field migration behavior of actinides may lead to significant underestimates and poor predictions of biosphere exposure from high-level waste (HLW) disposal. Existing data on colloid-facilitated transport suggests that radionuclide migration may be enhanced, but the importance of colloids is not adequately assessed. Indeed, the occurrence of radionuclide transport, attributed to colloidal species, has been reported at Mortandad Canyon, Los Alamos and at the Nevada Test Site; both unsaturated regions are similar to the proposed HLW repository at Yucca Mountain. Although some developments have been made on understanding the transport characteristics of colloids, the characterization of colloids generated from the corrosion of the waste form has been limited. Colloids are known to incorporate radionuclides either from hydrolysis of dissolved species (real colloids) or from adsorption of dissolved species onto existing groundwater colloids (pseudocolloids); however, these colloids may be considered secondary and solubility limited when compared to the colloids generated during glass alteration.
Download or read book Study on the Colloids Generated from Testing of High level Nuclear Waste Glasses written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The generation of colloids in the interaction of high-level nuclear waste glasses with groundwater at 90[degrees]C has been investigated. The stability of the colloidal suspensions has been characterized with respect to salt concentration, pH time, particle size, and zeta potential. The compositions and the morphology of the colloids have also been determined with transmission electron microscopy (TEM). From ourtest results combined with earlier ones, we conclude that the waste glass may contribute to the colloid formation by increasing ion concentration in groundwater, which causes nucleation of colloids; by releasing radionuclides that adsorb onto existing groundwater colloids; and by spalling colloidal-size fragments from the surface layer of the reacted glass. The colloids are silicon-rich particles, such as smectites and uranium silicates. When the salt concentration in the solution is high the colloidal suspensions agglomerate. However, the agglomerated particles can be resuspended if the salt concentration is lowered by dilution with groundwater. The colloids agglomerate quickly after the leachate is cooled to room temperature. Most of the colloids settle out of the solution within a few days at ambient temperature. The isoelectric point is at a pH of approximately 1.0. Between pH 1 and 10.5, the colloids are negatively charged, which suggests that they will deposit readily on, positively charged surfaces. The average particle size islargest at the isoelectric point and is smallest around pH 6.
Download or read book A Review of the President s Recommendation to Develop a Nuclear Waste Repository at Yucca Mountain Nevada written by United States. Congress. House. Committee on Energy and Commerce. Subcommittee on Energy and Air Quality and published by . This book was released on 2002 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Yucca Mountain Repository Development written by United States. Congress. Senate. Committee on Energy and Natural Resources and published by . This book was released on 2002 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Yucca Mountain Project written by and published by . This book was released on 2002 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
