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 The Role of Colloids in the Release of Radionuclides from Nuclear Waste written by United Kingdom Atomic Energy Authority and published by . This book was released on 1985 with total page 54 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 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 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 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 Behavior of Radionuclides in the Environment I written by Kenji Kato and published by Springer Nature. This book was released on 2020-02-18 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 3-volume set highlights the behavior of radionuclides in the environment and focusing on the development of related fields of study, including microbiology and nanoscience. In this context, it discusses the behavior of radionuclides released in areas of Lake Karachai in Ural, and those released as a result of Chernobyl accident (1986), and in Fukushima (2011). Volume I presents the experiences gained in South Urals (“Mayak” plant, Lake Karachai), providing a scientific basis for more precise understanding of the behavior of radionuclides in complex subsurface environments. On the basis of monitoring data, it examines the pathways of radionuclide migration and the influence of the geological environment and groundwater on the migration, with a particular focus on particles from the nanoscale to microscale. It also discusses the function of microbes and microscale particles, from their direct interaction with radionuclides to their ecological role in changing the physic-chemical condition of a given environment. Lastly, the protective properties of geological media are also characterized, and mathematical modeling of contaminant migration in the area of Lake Karachai is used to provide information regarding the migration of radionuclides.

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 The Role of Colloids in the Transport of Radionuclides in Geological Formations written by 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 Transport Code for Radiocolloid Migration written by and published by . This book was released on 1984 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, there is increased concern that radiocolloids may act as a rapid transport mechanism for the release of radionuclides from high-level waste repositories. The role of colloids is, however, controversial because the necessary data and assessment methodology have been limited. Evidence is accumulating to indicate that colloids are an important consideration in the geological disposal of nuclear waste. To quantitatively assess the role of colloids, the TRACR3D transport code has been enhanced by the addition of the population balance equations. This new version of the code can simulate the migration of colloids through combinations of porous/fractured, unsaturated, geologic media. The code was tested against the experimental laboratory column data of Avogadro et al. in order to compare the code results to both experimental data and an analytical solution. Next, a low-level radioactive waste site was investigated to explore whether colloid migration could account for the unusually rapid and long transport of plutonium and americium observed at a low-level waste site. Both plutonium and americium migrated 30 meters through unsaturated volcanic tuff. The nature and modeling of radiocolloids are discussed along with site simulation results from the TRACR3D code. 20 references.

Download or read book The Role of Colloids in the Transport of Radionuclides in Geological Formations written by A. Billon and published by . This book was released on 1991 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Natural Analogue Studies of the Role of Colloids Natural Organics and Microorganisms on Radionuclide Transport written by and published by . This book was released on 1994 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloids may be important as a geochemical transport mechanism for radionuclides at geological repositories if they are (1) present in the groundwater, (2) stable with respect to both colloidal and chemical stabilities, (3) capable of adsorbing radionuclides, especially if the sorption is irreversible, and (4) mobile in the subsurface. The available evidence from natural analogue and other field studies relevant to these issues is reviewed, as is the potential role of mobile microorganisms ({open_quotes}biocolloids{close_quotes}) on radionuclide migration. Studies have demonstrated that colloids are ubiquitous in groundwater, although colloid concentrations in deep, geochemically stable systems may be too low to affect radionuclide transport. However, even low colloid populations cannot be dismissed as a potential concern because colloids appear to be stable, and many radionuclides that adsorb to colloids are not readily desorbed over long periods. Field studies offer somewhat equivocal evidence concerning colloid mobility and cannot prove or disprove the significance of colloid transport in the far-field environment. Additional research is needed at new sites to properly represent a repository far-field. Performance assessment would benefit from natural analogue studies to examine colloid behavior at sites encompassing a suite of probable groundwater chemistries and that mimic the types of formations selected for radioactive waste repositories.

Download or read book Colloid Facilitated Radionuclide Transport written by and published by . This book was released on 2017 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides an overview of the current state of knowledge of colloid-facilitated radionuclide transport from a nuclear waste repository risk assessment perspective. It draws on work that has been conducted over the past 3 decades, although there is considerable emphasis given to work that has been performed over the past 3-5 years as part of the DOE Used Fuel Disposition Campaign. The timing of this report coincides with the completion of a 3-year DOE membership in the Colloids Formation and Migration (CFM) partnership, an international collaboration of scientists studying colloid-facilitated transport of radionuclides at both the laboratory and field-scales in a fractured crystalline granodiorite at the Grimsel Test Site in Switzerland. This Underground Research Laboratory has hosted the most extensive and carefully-controlled set of colloid-facilitated solute transport experiments that have ever been conducted in an in-situ setting, and a summary of the results to date from these efforts, as they relate to transport over long time and distance scales, is provided in Chapter 3 of this report.

Download or read book Geochemical Behavior of Disposed Radioactive Waste written by G. Scott Barney and published by . This book was released on 1984 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A review of the role of colloids in the release and transport of radionuclides in the near and far field written by E. Tipping 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 Literature Review of Intrinsic Actinide Colloids Related to Spent Fuel Waste Package Release Rates written by Pihong Zhao and published by . This book was released on 1997 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Existence of actinide colloids provides an important mechanism in the migration of radionuclides and will be important in performance of a geologic repository for high-level nuclear waste. Actinide colloids have been formed during long-term unsaturated dissolution of spent fuel by groundwater. This article summarizes a literature search of actinide colloids. This report emphasizes the formation of intrinsic actinide colloids, because they would have the opportunity to form soon after groundwater contact with the spent fuel and before actinide-bearing groundwater reaches the surrounding geologic formations.

Download or read book Radionuclide Retention in Geologic Media written by Svensk kärnbränslehantering AB. and published by Nuclear Energy Agency, Organisation for Economic Co-operation and Development. This book was released on 2002 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: GEOTRAP is the OECD/NEA Project on Radionuclide Migration in Geologic, Heterogeneous Media carried out in the context of site evaluation and safety assessment of deep repository systems for long-lived radioactive waste. Retention of radionuclides within the geosphere for prolonged periods is an important safety function of deep geologic disposal concepts for radioactive waste. The extent to which retention processes can be relied upon in repository performance assessment depends upon the existence of well-established theoretical bases for the processes. It also depends on support for the opera.