Download or read book Assessing Field scale Migration of Mobile Radionuclides at the Nevada Test Site written by and published by . This book was released on 2006 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous long-lived radionuclides, including 99Tc (technetium) and 129I (iodine), are present in groundwater at the Nevada Test Site (NTS) as a result of 828 underground nuclear weapons tests conducted between 1951 and 1992. We synthesize a body of groundwater data collected on the distribution of a number of radionuclides (3H, 14C, 36Cl, 99Tc and 129I), which are presumably mobile in the subsurface and potentially toxic to down-gradient receptors, to assess their migration at NTS, at field scales over distances of hundreds of meters and for durations of more than thirty years. Qualitative evaluation of field-scale migration of these radionuclides in the saturated zone provides an independent approach to validating their presumably conservative transport in the performance assessment of the proposed geological repository at Yucca Mountain, which is located on the western edge of NTS. The analyses show that the interaction of 3H with a solid surface via an isotopic exchange with clay lattice hydroxyls may cause a slight delay in the transport of 3H. The transport of 14C could be retarded by its isotopic exchange with carbonate minerals, and the exchange may be more pronounced in the alluvial aquifer. In particular, 99Tc may not necessarily exist as a mobile and conservative species 99TcO4−, as commonly assumed for NTS groundwater. This is corroborated with recent in situ redox potential measurements, both across and near Yucca Mountain, showing that groundwater at multiple locations is not oxidizing. Speciation of iodine and its associated reactivity and mobility is also complex in the groundwater at the NTS and deserves further attention. The assumption of no retardation for the transport of 99Tc (especially) and 129I, used at the performance assessment of Yucca Mountain repository, is probably overly conservative and results in unrealistically high estimated doses for down-gradient receptors.

Download or read book Laboratory and Field Studies Related to Radionuclide Migration at the Nevada Test Site in Support of the Underground Test Area and Hydrologic Resources Management Projects written by and published by . This book was released on 2002 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report details the work of Chemistry Division personnel from Los Alamos National Laboratory in FY 2001 for the U.S. Department of Energy National Nuclear Security Administration Nevada Operations Office (NNSA/NV) under its Defense Programs and Environmental Restoration divisions. Los Alamos is one of a number of agencies collaborating in an effort to describe the present and future movement of radionuclides in the underground environment of the Nevada Test Site. This fiscal year we collected and analyzed water samples from a number of expended test locations at the Nevada Test Site. We give the results of these analyses and summarize the information gained over the quarter century that we have been studying several of these sites. We find that by far most of the radioactive residues from a nuclear test are contained in the melt glass in the cavity. Those radionuclides that are mobile in water can be transported if the groundwater is moving due to hydraulic or thermal gradients. The extent to which they move is a function of their chemical speciation, with neutral or anionic materials traveling freely relative to cationic materials that tend to sorb on rock surfaces. However, radionuclides sorbed on colloids may be transported if the colloids are moving. Local conditions strongly influence the distribution and movement of radionuclides, and we continue to study sites such as Almendro, which is thermally quite hot, and Nash and Bourbon, where radionuclides had not been measured for 8 years. We collected samples from three characterization wells in Frenchman Flat to obtain baseline radiochemistry data for each well, and we analyzed eight wells containing radioactivity for 237Np, using our highly sensitive ICP/MS. We have again used our field probe that allows us to measure important groundwater properties in situ. We conclude our report by noting document reviews and publications produced in support of this program.

Download or read book Laboratory and Field Studies Related to Radionuclide Migration at the Nevada Test Site in Support of the Underground Test Area Program and Hydrologic Resources Management Project October 1 1999 September 30 2000 written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report details the work of Chemistry Division personnel from Los Alamos National Laboratory in FY 2000 for the US Department of Energy/Nevada Operations Office under their Defense Programs and Environmental Restoration Divisions. Los Alamos is one of a number of agencies collaborating in an effort to describe the present and future movement of radionuclides in the underground environment of the Nevada Test Site. This fiscal year we collected and analyzed water samples from a number of expended test locations at the Nevada Test Site. We give the results of these analyses and summarize the information gained over the quarter century that we have been studying several of these sites. We find that by far most of the radioactive residues from a nuclear test are contained in the melt glass in the cavity. Those radionuclides that are mobile in water can be transported if the groundwater is moving due to hydraulic or thermal gradients. The extent to which they move is a function of their chemical speciation, with neutral or anionic materials traveling freely relative to cationic materials that tend to sorb on rock surfaces. However, radionuclides sorbed on colloids may be transported if the colloids are moving. Local conditions strongly influence the distribution and movement of radionuclides, and we continue to study sites such as Almendro, which is thermally quite hot, and Bilby where radionuclides do not appear to have moved a short distance from the cavity. We have begun field use of a tool that allows us to measure important groundwater properties in situ. We conclude our report by noting document reviews and publications produced in support of this program.

Download or read book Radionuclide Migration Studies at the Nevada Test Site written by and published by . This book was released on 1989 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States government routinely tests nuclear devices at the Nevada Test Site (NTS) in southern Nevada. A significant amount of radioactive material exists underground at the NTS with no containers or engineered barriers to inhibit its subsequent migration. The Department of Energy has sponsored for many years a research program on radionuclide movement in the geologic media at this location. Goals of this research program are to measure the extent of movement of radionuclides away from underground explosion sites and to determine the mechanisms by which such movement occurs. This program has acquired significance in another aspect of nuclear waste management because of the Yucca Mountain Project. Yucca Mountain at the NTS is being intensively studied as the possible site for a mined repository for high level nuclear waste. The NTS provides a unique setting for field studies concerning radionuclide migration; there is the potential for greatly increasing our knowledge of the behavior of radioactive materials in volcanogenic media. This review summarizes some of the significant findings made under this research program at the NTS and identifies reports in which the details of the research may be found. 36 refs., 4 figs.

Download or read book Field Scale Migration of 99Tc and 129I at the Nevada Test Site written by and published by . This book was released on 2004 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The groundwater at the Nevada Test Site (NTS) contains many long-lived radionuclides, including 99Tc (technetium) and 129I (iodine), as a result of 828 underground nuclear weapons tests conducted between 1951 and 1992. We synthesized a body of data collected on the distribution of 99Tc and 129I in groundwater to assess their migration at NTS, at field scales over distances of hundreds of meters and for durations up to forty years and under hydrogeologic conditions very similar to the proposed geological repository at Yucca Mountain. The results of our study show that Tc does not necessarily exist as a mobile and conservative species TcO4−, as has been commonly assumed. This conclusion is corroborated by recent in situ redox potential measurements, which show that groundwaters at multiple locations of the NTS are not oxidizing, and mobility of reduced Tc species (TcO2 · nH2O) is greatly decreased. Speciation of iodine and its associated reactivity is also complex in the groundwater at the NTS, and its effect on the mobility of iodine should be the subject of future studies.

Download or read book Laboratory and Field Studies Related to Radionuclide Migration at the Nevada Test Site written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report, we describe the work done in FY 1998 at Los Alamos National Laboratory as part of the Hydrologic Resources Management Program (HRMA) funded by the Nevada Operations Office of the US Department of Energy (DOE/NV). The major part of our research effort was to measure radionuclides present in water or soil samples collected from near nuclear tests. We report our measurements for materials collected in both saturated and unsaturated horizons adjacent to nuclear test cavities or collapse chimneys and from within several cavities. Soil samples collected from above the cavities formed by the Halfbeak, Jerboa, and Bobac tests contained no radioactivity, although a test similar to Bobac in the same area had been contaminated with 137Cs. Water samples from near the Shoal test contained no measurable radionuclides, whereas those from near Faultless and Aleman had concentrations similar to previous measurements. Water from the Tybo-Benham site was similar to earlier collections at that site; this year, we added 241Am to the list of radionuclides measured at this location. Two Bennett pumps in tandem were used to extract water from the piezometer tube in the cavity of the Dalhart event. This extraction is a significant achievement in that it opens the possibility of purging similar tubes at other locations on the NTS. The Cheshire post shot hole was reconfigured and pumped from two horizons for the first time since mid-1980. We are especially interested in examining water from the level of the working point to determine the hydrologic source term in a cavity filled with groundwater for over 20 years. We devoted much time this year to examining the colloid content of NTS groundwater. After developing protocols for collecting, handling, and storing groundwater samples without altering their colloid content, we analyzed water from the Tybo-Benham and from the Cheshire sites. Whereas the colloid concentration did not vary much with depth at Tybo-Benham, there were 20 times more colloids in groundwater from the Cheshire cavity than were found a few hundred meters higher. Electron micrographs show the wide variety of colloid sizes and shapes present in NTS groundwater. Our experiences with filtration of groundwater samples illustrate the difficulties of colloid size characterization using this methodology. Our report ends with a description of our consultative and educational activities and a list of recent publications.

Download or read book Actinide Nanoparticle Research written by Stepan N. Kalmykov and published by Springer Science & Business Media. This book was released on 2011-06-17 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book to cover actinide nano research. It is of interest both for fundamental research into the chemistry and physics of f-block elements as well as for applied researchers such as those studying the long-term safety of nuclear waste disposal and developing remediation strategies. The authors cover important issues of the formation of actinide nano-particles, their properties and structure, environmental behavior of colloids and nanoparticles related to the safe disposal of nuclear wastes, modeling and advanced methods of characterization at the nano-scale.

Download or read book Modified Clay and Zeolite Nanocomposite Materials written by Mariano Mercurio and published by Elsevier. This book was released on 2018-11-29 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modified Clay and Zeolite Nanocomposite Materials: Environmental and Pharmaceutical Applications retraces the most important knowledge gaps that the scientific community is facing, including a drawback of real-world applications. This valuable resource explores the novel applications of this group of nanomaterials that can be suitably surface-modified to obtain properties that can be applied in environmental and pharmaceutical fields. For example, modification with surfactants has given new motivation to the study of these materials by producing an inversion in the ion exchange behavior from cationic to anionic. This strategy has paved the way for new uses highlighted in this timely resource. Explores the combination of both minerals (clay and zeolite) together, with their application in two broad areas of emerging research Explains better utilization and applications for modified clay and zeolite through detailed comparative studies Consolidates information on the modification and tuning of clay and zeolite materials for novelty applications Helps users in the selection of materials, surface features, and other functionalization for diverse applications

Download or read book Geological Melts written by Daniel R. Neuville and published by Walter de Gruyter GmbH & Co KG. This book was released on 2022-07-04 with total page 1108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 87 of Reviews in Mineralogy and Geochemistry covers fundamental aspects of the nature of silicate melts and the implications for the systems in which they participate, both technological and natural. The contents of this volume may perhaps best be summarized as structure – properties – dynamics. The volume contains syntheses of short and medium range order, structure-property relationships, and computation-based simulations of melt structure. It continues with analyses of the properties (mechanical, diffusive, thermochemical, redox, nucleation, rheological) of melts. The dynamic behavior of melts in magmatic and volcanic systems, is then treated in the context of their behavior in magma mixing, strain localization, frictional melting, magmatic fragmentation, and hot sintering. Finally, the non-magmatic, extraterrestrial and prehistoric roles of melt and glass are presented in their respective contexts.

Download or read book Springer Handbook of Glass written by J. David Musgraves and published by Springer Nature. This book was released on 2019-11-08 with total page 1851 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook provides comprehensive treatment of the current state of glass science from the leading experts in the field. Opening with an enlightening contribution on the history of glass, the volume is then divided into eight parts. The first part covers fundamental properties, from the current understanding of the thermodynamics of the amorphous state, kinetics, and linear and nonlinear optical properties through colors, photosensitivity, and chemical durability. The second part provides dedicated chapters on each individual glass type, covering traditional systems like silicates and other oxide systems, as well as novel hybrid amorphous materials and spin glasses. The third part features detailed descriptions of modern characterization techniques for understanding this complex state of matter. The fourth part covers modeling, from first-principles calculations through molecular dynamics simulations, and statistical modeling. The fifth part presents a range of laboratory and industrial glass processing methods. The remaining parts cover a wide and representative range of applications areas from optics and photonics through environment, energy, architecture, and sensing. Written by the leading international experts in the field, the Springer Handbook of Glass represents an invaluable resource for graduate students through academic and industry researchers working in photonics, optoelectronics, materials science, energy, architecture, and more.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1994 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.

Download or read book Monitored Natural Attenuation of Inorganic Contaminants in Ground Water written by and published by . This book was released on 2007 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: V.3 ... consists of individual chapters that describe 1) the conceptual background for radionuclides, including tritium, radon, strontium, technetium, uranium, iodine, radium, thorium, cesium, plutonium-americium and 2) data requirements to be met during site characterization.

Download or read book Environmental Consequences of the Chernobyl Accident and Their Remediation written by International Atomic Energy Agency and published by IAEA. This book was released on 2006 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: The explosion on 26 April 1986 at the Chernobyl nuclear power plant and the consequent reactor fire resulted in an unprecedented release of radioactive material from a nuclear reactor and adverse consequences for the public and the environment. Although the accident occurred nearly two decades ago, controversy still surrounds the real impact of the disaster. Therefore the IAEA, in cooperation with other UN bodies, the World Bank, as well as the competent authorities of Belarus, the Russian Federation and Ukraine, established the Chernobyl Forum in 2003. The mission of the Forum was to generate 'authoritative consensual statements' on the environmental consequences and health effects attributable to radiation exposure arising from the accident as well as to provide advice on environmental remediation and special health care programmes, and to suggest areas in which further research is required. This report presents the findings and recommendations of the Chernobyl Forum concerning the environmental effects of the Chernobyl accident.

Download or read book Disposition of High Level Waste and Spent Nuclear Fuel written by National Research Council and published by National Academies Press. This book was released on 2001-07-05 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focused attention by world leaders is needed to address the substantial challenges posed by disposal of spent nuclear fuel from reactors and high-level radioactive waste from processing such fuel. The biggest challenges in achieving safe and secure storage and permanent waste disposal are societal, although technical challenges remain. Disposition of radioactive wastes in a deep geological repository is a sound approach as long as it progresses through a stepwise decision-making process that takes advantage of technical advances, public participation, and international cooperation. Written for concerned citizens as well as policymakers, this book was sponsored by the U.S. Department of Energy, U.S. Nuclear Regulatory Commission, and waste management organizations in eight other countries.

Download or read book Scientific Basis for Nuclear Waste Management written by and published by . This book was released on 2004 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flow and Transport in Porous Media and Fractured Rock written by Muhammad Sahimi and published by John Wiley & Sons. This book was released on 2011-05-09 with total page 635 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this standard reference of the field, theoretical and experimental approaches to flow, hydrodynamic dispersion, and miscible displacements in porous media and fractured rock are considered. Two different approaches are discussed and contrasted with each other. The first approach is based on the classical equations of flow and transport, called 'continuum models'. The second approach is based on modern methods of statistical physics of disordered media; that is, on 'discrete models', which have become increasingly popular over the past 15 years. The book is unique in its scope, since (1) there is currently no book that compares the two approaches, and covers all important aspects of porous media problems; and (2) includes discussion of fractured rocks, which so far has been treated as a separate subject. Portions of the book would be suitable for an advanced undergraduate course. The book will be ideal for graduate courses on the subject, and can be used by chemical, petroleum, civil, environmental engineers, and geologists, as well as physicists, applied physicist and allied scientists that deal with various porous media problems.

Download or read book The Office of Environmental Management Technical Reports A Bibliography written by and published by DIANE Publishing. This book was released on 2001 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Office of Environmental Management's (EM) technical reports bibliography is an annual publication that contains information on scientific and technical reports sponsored by the Office of Environmental Management added to the Energy Science and Technology Database from July 1, 1994 through June 30, 1995. This information is divided into the following categories: Focus Areas, Cross-Cutting Programs, and Support Programs. In addition, a category for general information is included. EM's Office of Science and Technology sponsors this bibliography.