Science.gov

Sample records for alkaline nuclear waste

  1. Raman study of aluminum speciation in simulated alkaline nuclear waste.

    PubMed

    Johnston, Cliff T; Agnew, Stephen F; Schoonover, Jon R; Kenney, John W; Page, Bobbi; Osborn, Jill; Corbin, Rob

    2002-06-01

    The chemistry of concentrated sodium aluminate solutions stored in many of the large, underground storage tanks containing high-level waste (HLW) at the Hanford and Savannah River Nuclear Reservations is an area of recent research interest. Not only is the presence of aluminate in solution important for continued safe storage of these wastes, the nature of both solid and solution aluminum oxyhydroxides is important for waste pretreatment. Moreover, for many tanks that have leaked high aluminum waste in the past, little is known about the speciation of Al in the soil. In this study, Raman spectroscopy has been used to investigate the speciation of the aqueous species in the Al2O3-Na2O-H2O system over a wide range of solution compositions and hydration. A ternary phase diagram has been used to correlate the observed changes in the spectra with the composition of the solution and with dimerization of aluminate that occurs at elevated aluminate concentrations (>1.5 M). Dimerization is evidenced by growth of new Al-O stretching bands at 535 and 695 cm(-1) at the expense of the aluminate monomer band at 620 cm(-1). The spectrum of water was strongly influenced by the high concentrations of Na+ and OH- (>17 M). Upon increasing the concentration of NaOH in solution, the delta-(H-O-H) bending band of water (v2 mode) increased in frequency to 1663 cm(-1), indicating that the water contained in the concentrated caustic solution was more strongly hydrogen bonded at the higher base content. In addition, the sharp, well-resolved band at 3610 cm(-1), assigned to the v(O-H) of free OH-, increased in intensity with increasing NaOH. Analysis of the v(O-H) bands in the 3800-2600 cm(-1) region supported the overall increase in hydrogen bonding as evidenced by the increase in relative intensity of a strongly hydrated water band at 3118 cm(-1). Taking into consideration the activity of water, the molar concentrations of the monomeric and dimeric aluminate species were estimated using

  2. Electrochemical Treatment of Alkaline Nuclear Wastes. Innovative Technology Summary Report

    SciTech Connect

    2001-01-01

    Nitrate and nitrite are two of the major hazardous non-radioactive species present in Hanford and Savannah River (SR) high-level waste (HLW). Electrochemical treatment processes have been developed to remove these species by converting aqueous sodium nitrate/nitrite into sodium hydroxide and chemically reducing the nitrogen species to gaseous ammonia, nitrous oxide and nitrogen. Organic complexants and other organic compounds found in waste can be simultaneously oxidized to gaseous carbon dioxide and water, thereby reducing flammability and leaching risks as well as process interferences in subsequent radionuclide separation processes. Competing technologies include thermal, hydrothermal and chemical destruction. Unlike thermal and hydrothermal processes that typically operate at very high temperatures and pressures, electrochemical processes typically operate at low temperatures (<100 C) and atmospheric pressure. Electrochemical processes effect chemical transformations by the addition or removal of electrons and, thus, do not add additional chemicals, as is the case with chemical destruction processes. Hanford and SR have different plans for disposal of the low-activity waste (LAW) that results when radioactive Cs{sup 137} has been removed from the HLW. At SR, the decontaminated salt solution will be disposed in a cement waste form referred to as Saltstone, whereas at Hanford the waste will be vitrified as a borosilicate glass. Destruction of the nitrate and nitrite before disposing the decontaminated salt solution in Saltstone would eliminate possible groundwater contamination that could occur from the leaching of nitrate and nitrite from the cement waste form. Destruction of nitrate and nitrite before vitrification at Hanford would significantly reduce the size of the off-gas system by eliminating the formation of NO{sub x} gases in the melter. Throughout the 1990's, the electrochemical conversion process has been extensively studied at SR, the University of

  3. Summary technical report on the electrochemical treatment of alkaline nuclear wastes

    SciTech Connect

    Hobbs, D.T.

    1994-07-30

    This report summarizes the laboratory studies investigating the electrolytic treatment of alkaline solutions carried out under the direction of the Savannah River Technology Center from 1985-1992. Electrolytic treatment has been demonstrated at the laboratory scale to be feasible for the destruction of nitrate and nitrite and the removal of radioactive species such as {sup 99}Tc and {sup 106}Ru from Savannah River Site (SRS) decontaminated salt solution and other alkaline wastes. The reaction rate and current efficiency for the removal of these species are dependent on cell configuration, electrode material, nature of electrode surface, waste composition, current density, and temperature. Nitrogen, ammonia, and nitrous oxide have been identified as the nitrogen-containing reaction products from the electrochemical reduction of nitrate and nitrite under alkaline conditions. The reaction mechanism for the reduction is very complex. Voltammetric studies indicated that the electrode reactions involve surface phenomena and are not necessarily mass transfer controlled. In an undivided cell, results suggest an electrocatalytic role for oxygen via the generation of the superoxide anion. In general, more efficient reduction of nitrite and nitrate occurs at cathode materials with higher overpotentials for hydrogen evolution. Nitrate and nitrite destruction has also been demonstrated in engineering-scale flow reactors. In flow reactors, the nitrate/nitrite destruction efficiency is improved with an increase in the current density, temperature, and when the cell is operated in a divided cell configuration. Nafion{reg_sign} cation exchange membranes have exhibited good stability and consistent performance as separators in the divided-cell tests. The membranes were also shown to be unaffected by radiation at doses approximating four years of cell operation in treating decontaminated salt solution.

  4. Development of a carbonate crust on alkaline nuclear waste sludge at the Hanford site.

    PubMed

    Page, Jason S; Reynolds, Jacob G; Ely, Tom M; Cooke, Gary A

    2017-08-18

    Hard crusts on aging plutonium production waste have hindered the remediation of the Hanford Site in southeastern Washington, USA. In this study, samples were analyzed to determine the cause of a hard crust that developed on the highly radioactive sludge during 20 years of inactivity in one of the underground tanks (tank 241-C-105). Samples recently taken from the crust were compared with those acquired before the crust appeared. X-ray diffraction and scanning electron microscopy (SEM) indicated that aluminum and uranium phases at the surface had converted from (hydr)oxides (gibbsite and clarkeite) into carbonates (dawsonite and cejkaite) and identified trona as the cementing phase, a bicarbonate that formed at the expense of thermonatrite. Since trona is more stable at lower pH values than thermonatrite, the pH of the surface decreased over time, suggesting that CO2 from the atmosphere lowered the pH. Thus, a likely cause of crust formation was the absorption of CO2 from the air, leading to a reduction of the pH and carbonation of the waste surface. The results presented here help establish a model for how nuclear process waste can age and can be used to aid future remediation and retrieval activities. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Nuclear waste

    SciTech Connect

    Not Available

    1991-09-01

    Radioactive waste is mounting at U.S. nuclear power plants at a rate of more than 2,000 metric tons a year. Pursuant to statute and anticipating that a geologic repository would be available in 1998, the Department of Energy (DOE) entered into disposal contracts with nuclear utilities. Now, however, DOE does not expect the repository to be ready before 2010. For this reason, DOE does not want to develop a facility for monitored retrievable storage (MRS) by 1998. This book is concerned about how best to store the waste until a repository is available, congressional requesters asked GAO to review the alternatives of continued storage at utilities' reactor sites or transferring waste to an MRS facility, GAO assessed the likelihood of an MRSA facility operating by 1998, legal implications if DOE is not able to take delivery of wastes in 1998, propriety of using the Nuclear Waste Fund-from which DOE's waste program costs are paid-to pay utilities for on-site storage capacity added after 1998, ability of utilities to store their waste on-site until a repository is operating, and relative costs and safety of the two storage alternatives.

  6. Nuclear waste

    SciTech Connect

    Not Available

    1988-05-01

    This paper discusses how, as part of the Department of Energy's implementation of the Nuclear Waste Policy Act of 1982, DOE is required to investigate a site at Yucca Mountain, Nevada and, if it determines that the site is suitable, recommend to the President its selection for a nuclear waste repository. The Nuclear Regulatory Commission, in considering development of the plan, issued five objections, one of which is DOE's failure to recognize the range of alternative conceptual models of the Yucca Mountain site that can be supported by the limited existing technical data. At the end of the quarter DOE directed its project offices in Washington and Texas to begin orderly phase-out of all site-specific repository activities. Costs for this phase-out are $53 million for the Deaf Smith site and $85 million for the Hanford site.

  7. Nuclear Waste Disposal

    SciTech Connect

    Gee, Glendon W.; Meyer, Philip D.; Ward, Andy L.

    2005-01-12

    Nuclear wastes are by-products of nuclear weapons production and nuclear power generation, plus residuals of radioactive materials used by industry, medicine, agriculture, and academia. Their distinctive nature and potential hazard make nuclear wastes not only the most dangerous waste ever created by mankind, but also one of the most controversial and regulated with respect to disposal. Nuclear waste issues, related to uncertainties in geologic disposal and long-term protection, combined with potential misuse by terrorist groups, have created uneasiness and fear in the general public and remain stumbling blocks for further development of a nuclear industry in a world that may soon be facing a global energy crisis.

  8. Radioactive Demonstration of Caustic Recovery from Low-Level Alkaline Nuclear Waste by an Electrochemical Separation Process

    SciTech Connect

    Hobbs, D.T.

    1998-04-01

    Bench-scale radioactive tests successfully demonstrated an electrochemical process for the recovery of sodium hydroxide (caustic) from Decontaminated Salt Solution produced from the In-Tank Precipitation and Effluent Treatment Processes at the Savannah River Site (SRS). This testing evaluated two membranes: an organic-based membrane, Nafion Type 350, manufactured by E. I. duPont de Nemours {ampersand} Company, Inc. (DuPont) and an inorganic-based membrane, NAS D, being developed by Ceramatec. Both membranes successfully separated caustic from radioactive SRS waste.Key findings of the testing indicate the following attributes and disadvantages of each membrane. The commercially-available Nafion membrane proved highly conductive. Thus, the electrochemical cell can operate at high current density minimizing the number of cells at the desired volumetric processing rate. Testing indicated cesium transported across the Nafion membrane into the caustic product. Therefore, the caustic product will contain low-levels of radioactive cesium due to the presence of {sup 134,137}Cs in the waste feed. To meet customer requirements, a post treatment stage may prove necessary to remove radioactive cesium resulting in increased overall process costs and decreased cost savings. In contrast to the Nafion membrane, the NAS D membrane demonstrated the production of caustic with much lower levels of gamma radioactivity ({sup 137}Cs activity was {lt} 51 dpm/g). Therefore, the caustic product could possibly release for onsite/offsite use without further treatment. The NAS D membrane remains in the development stage and does not exist as a commercial product. Operating costs and long-term membrane durability remain unknown.Caustic recovery has been successfully demonstrated in a bench-scale, 2-compartment electrochemical reactor operated for brief periods of time with simulated and radioactive waste solutions and two different types of membranes. The next phase of testing should be directed

  9. Nuclear waste management

    NASA Astrophysics Data System (ADS)

    Chikalla, T. D.; Powell, J. A.

    1981-09-01

    Reports and summaries are presented for the following: high-level waste process development; alternative waste forms; TMI zeolite vitrification demonstration program; nuclear waste materials characterization center; TRU waste immobilization; TRU waste decontamination; krypton implantation; thermal outgassing; iodine-129 fixation; NWVP off-gas analysis; monitoring and physical characterization of unsaturated zone transport; well-logging instrumentation development; verification instrument development; mobility of organic complexes of radionuclides in soils; handbook of methods to decrease the generation of low-level waste; waste management system studies; waste management safety studies; assessment of effectiveness of geologic isolation systems; waste/rock interactions technology program; high-level waste form preparation; development of backfill materials; development of structural engineered barriers; disposal charge analysis; and analysis of spent fuel policy implementation.

  10. Politics of nuclear waste

    SciTech Connect

    Colglazier, E.W. Jr.

    1982-01-01

    In November of 1979, the Program in Science, Technology and Humanism and the Energy Committee of the Aspen Institute organized a conference on resolving the social, political, and institutional conflicts over the permanent siting of radioactive wastes. This book was written as a result of this conference. The chapters provide a comprehensive and up-to-date overview of the governance issues connected with radioactive waste management as well as a sampling of the diverse views of the interested parties. Chapter 1 looks in depth of radioactive waste management in the United States, with special emphasis on the events of the Carter Administration as well as on the issues with which the Reagen administration must deal. Chapter 2 compares waste management policies and programs among the industralized countries. Chapter 3 examines the factional controversies in the last administration and Congress over nuclear waste issues. Chapter 4 examines the complex legal questions involved in the federal-state conflicts over nuclear waste management. Chapter 5 examines the concept of consultation and concurrence from the perspectives of a host state that is a candidate for a repository and an interested state that has special concerns regarding the demonstration of nuclear waste disposal technology. Chapter 6 examines US and European perspectives concerning public participation in nuclear waste management. Chapter 7 discusses propaganda in the issues. The epilogue attempts to assess the prospects for consensus in the United States on national policies for radioactive waste management. All of the chapter in this book should be interpreted as personal assessments. (DP)

  11. High level nuclear waste

    SciTech Connect

    Crandall, J L

    1980-01-01

    The DOE Division of Waste Products through a lead office at Savannah River is developing a program to immobilize all US high-level nuclear waste for terminal disposal. DOE high-level wastes include those at the Hanford Plant, the Idaho Chemical Processing Plant, and the Savannah River Plant. Commercial high-level wastes, for which DOE is also developing immobilization technology, include those at the Nuclear Fuel Services Plant and any future commercial fuels reprocessing plants. The first immobilization plant is to be the Defense Waste Processing Facility at Savannah River, scheduled for 1983 project submission to Congress and 1989 operation. Waste forms are still being selected for this plant. Borosilicate glass is currently the reference form, but alternate candidates include concretes, calcines, other glasses, ceramics, and matrix forms.

  12. Nuclear waste solutions

    DOEpatents

    Walker, Darrel D.; Ebra, Martha A.

    1987-01-01

    High efficiency removal of technetium values from a nuclear waste stream is achieved by addition to the waste stream of a precipitant contributing tetraphenylphosphonium cation, such that a substantial portion of the technetium values are precipitated as an insoluble pertechnetate salt.

  13. Process for treating alkaline wastes for vitrification

    DOEpatents

    Hsu, Chia-lin W.

    1994-01-01

    According to its major aspects and broadly stated, the present invention is a process for treating alkaline waste materials, including high level radioactive wastes, for vitrification. The process involves adjusting the pH of the wastes with nitric acid, adding formic acid (or a process stream containing formic acid) to reduce mercury compounds to elemental mercury and MnO{sub 2} to the Mn(II) ion, and mixing with class formers to produce a melter feed. The process minimizes production of hydrogen due to noble metal-catalyzed formic acid decomposition during, treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product. An important feature of the present invention is the use of different acidifying and reducing, agents to treat the wastes. The nitric acid acidifies the wastes to improve yield stress and supplies acid for various reactions; then the formic acid reduces mercury compounds to elemental mercury and MnO{sub 2}) to the Mn(II) ion. When the pH of the waste is lower, reduction of mercury compounds and MnO{sub 2}) is faster and less formic acid is needed, and the production of hydrogen caused by catalytically-active noble metals is decreased.

  14. Environmental Hazards of Nuclear Wastes

    ERIC Educational Resources Information Center

    Micklin, Philip P.

    1974-01-01

    Present methods for storage of radioactive wastes produced at nuclear power facilities are described. Problems arising from present waste management are discussed and potential solutions explored. (JP)

  15. Environmental Hazards of Nuclear Wastes

    ERIC Educational Resources Information Center

    Micklin, Philip P.

    1974-01-01

    Present methods for storage of radioactive wastes produced at nuclear power facilities are described. Problems arising from present waste management are discussed and potential solutions explored. (JP)

  16. Swedish nuclear waste efforts

    SciTech Connect

    Rydberg, J.

    1981-09-01

    After the introduction of a law prohibiting the start-up of any new nuclear power plant until the utility had shown that the waste produced by the plant could be taken care of in an absolutely safe way, the Swedish nuclear utilities in December 1976 embarked on the Nuclear Fuel Safety Project, which in November 1977 presented a first report, Handling of Spent Nuclear Fuel and Final Storage of Vitrified Waste (KBS-I), and in November 1978 a second report, Handling and Final Storage of Unreprocessed Spent Nuclear Fuel (KBS II). These summary reports were supported by 120 technical reports prepared by 450 experts. The project engaged 70 private and governmental institutions at a total cost of US $15 million. The KBS-I and KBS-II reports are summarized in this document, as are also continued waste research efforts carried out by KBS, SKBF, PRAV, ASEA and other Swedish organizations. The KBS reports describe all steps (except reprocessing) in handling chain from removal from a reactor of spent fuel elements until their radioactive waste products are finally disposed of, in canisters, in an underground granite depository. The KBS concept relies on engineered multibarrier systems in combination with final storage in thoroughly investigated stable geologic formations. This report also briefly describes other activities carried out by the nuclear industry, namely, the construction of a central storage facility for spent fuel elements (to be in operation by 1985), a repository for reactor waste (to be in operation by 1988), and an intermediate storage facility for vitrified high-level waste (to be in operation by 1990). The R and D activities are updated to September 1981.

  17. Process for treating alkaline wastes for vitrification

    DOEpatents

    Hsu, Chia-lin W.

    1995-01-01

    A process for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO.sub.2 to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO.sub.2, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product.

  18. Process for treating alkaline wastes for vitrification

    DOEpatents

    Hsu, C.L.W.

    1995-07-25

    A process is described for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO{sub 2} to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO{sub 2}, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product. 4 figs.

  19. Removal of plutonium and americium from alkaline waste solutions

    DOEpatents

    Schulz, Wallace W.

    1979-01-01

    High salt content, alkaline waste solutions containing plutonium and americium are contacted with a sodium titanate compound to effect removal of the plutonium and americium from the alkaline waste solution onto the sodium titanate and provide an effluent having a radiation level of less than 10 nCi per gram alpha emitters.

  20. Military nuclear waste disposal

    NASA Astrophysics Data System (ADS)

    Robb, David W.

    1984-04-01

    A National Research Council (NRC) panel has endorsed a plan for a proposed underground military nuclear waste disposal facility located on a site near Carlsbad, N.M. The Department of Energy (DOE) asked NRC to evaluate the geologic suitability of the site.The NRC panel, chaired by Frank L. Parker of Vanderbilt University, concluded in its final report that “the important issues about the geology of the site have been resolved…” Those issues include the purity and volume of salt, the absence of brine pockets at the repository horizon in the areas excavated, the absence of breccia pipes and of toxic gases, and the nearly horizontal bedding of the salt. Thick underground salt beds have long been considered prime candidates for nuclear waste repositories. The existence of salt beds is believed to indicate long-term stability. In addition, the salt is flexible and will seal cracks and discontinuities over time.

  1. Nuclear waste management: a perspective

    SciTech Connect

    Leuze, R.E.

    1980-01-01

    The scope of our problems with nuclear waste management is outlined. Present and future inventories of nuclear wastes are assessed for risk. A discussion of what is presently being done to solve waste management problems and what might be done in the future are presented. (DC)

  2. Turning nuclear waste into glass

    SciTech Connect

    Pegg, Ian L.

    2015-02-15

    Vitrification has emerged as the treatment option of choice for the most dangerous radioactive waste. But dealing with the nuclear waste legacy of the Cold War will require state-of-the-art facilities and advanced glass formulations.

  3. Underground nuclear waste containments

    SciTech Connect

    Bandyopadhyay, K.K.

    1995-11-01

    In the United States, about a hundred million gallons of high-level nuclear waste are stored in underground containments. Basically, these containments are of two different designs: single-shell and double-shell structures. The single-shell structures consist of reinforced concrete cylindrical walls seated on circular mats and enclosed on top with torispherical domes or circular flat roofs. The walls and the basemats are lined with carbon steel. The double-shell structures provide another layer of protection and constitute a completely enclosed steel containment within the single-shell structure leaving an annular space between the two walls. Single-shell containments are of earlier vintage and were built in the period 1945-1965. Double-shell structures were built through the 1960s and 1970s. Experience gained in building and operating the single-shell containments was used in enhancing the design and construction of the double-shell structures. Currently, there are about 250 underground single-shell and double-shell structures containing the high-level waste with an inventory of about 800 million curies. During their service lives, especially in early stages, these structures were subjected to thermal excursions of varying extents; also, they have aged in the chemical environment. Furthermore, in their remaining service lives, the structures may be subjected to loads for which they were not designed, such as larger earthquakes or chemical explosions. As a result, the demonstration of safety of these underground nuclear containments poses a challenge to structural engineers, which increases with time. Regardless of current plans for gradual retrieval of the waste and subsequent solidification for disposal, many of these structures are expected to continue to contain the waste through the next 20-40 years. In order to verify their structural capabilities in fulfilling this mission, several studies were recently performed at Brookhaven National Laboratory.

  4. Waste canister for storage of nuclear wastes

    DOEpatents

    Duffy, James B.

    1977-01-01

    A waste canister for storage of nuclear wastes in the form of a solidified glass includes fins supported from the center with the tips of the fins spaced away from the wall to conduct heat away from the center without producing unacceptable hot spots in the canister wall.

  5. Nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Burns, R. E.; Causey, W. E.; Galloway, W. E.; Nelson, R. W.

    1978-01-01

    Work on nuclear waste disposal in space conducted by the George C. Marshall Space Flight Center, National Aeronautics and Space Administration, and contractors are reported. From the aggregate studies, it is concluded that space disposal of nuclear waste is technically feasible.

  6. Space disposal of nuclear wastes

    NASA Technical Reports Server (NTRS)

    Priest, C. C.; Nixon, R. F.; Rice, E. E.

    1980-01-01

    The DOE has been studying several options for nuclear waste disposal, among them space disposal, which NASA has been assessing. Attention is given to space disposal destinations noting that a circular heliocentric orbit about halfway between Earth and Venus is the reference option in space disposal studies. Discussion also covers the waste form, showing that parameters to be considered include high waste loading, high thermal conductivity, thermochemical stability, resistance to leaching, fabrication, resistance to oxidation and to thermal shock. Finally, the Space Shuttle nuclear waste disposal mission profile is presented.

  7. Space disposal of nuclear wastes

    NASA Technical Reports Server (NTRS)

    Priest, C. C.; Nixon, R. F.; Rice, E. E.

    1980-01-01

    The DOE has been studying several options for nuclear waste disposal, among them space disposal, which NASA has been assessing. Attention is given to space disposal destinations noting that a circular heliocentric orbit about halfway between Earth and Venus is the reference option in space disposal studies. Discussion also covers the waste form, showing that parameters to be considered include high waste loading, high thermal conductivity, thermochemical stability, resistance to leaching, fabrication, resistance to oxidation and to thermal shock. Finally, the Space Shuttle nuclear waste disposal mission profile is presented.

  8. Nuclear waste solidification

    DOEpatents

    Bjorklund, William J.

    1977-01-01

    High level liquid waste solidification is achieved on a continuous basis by atomizing the liquid waste and introducing the atomized liquid waste into a reaction chamber including a fluidized, heated inert bed to effect calcination of the atomized waste and removal of the calcined waste by overflow removal and by attrition and elutriation from the reaction chamber, and feeding additional inert bed particles to the fluidized bed to maintain the inert bed composition.

  9. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    SciTech Connect

    Delegard, C.H.; Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K.

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes.

  10. Neutron transmutation of nuclear waste

    NASA Astrophysics Data System (ADS)

    Hoffman, Edward Albert

    Two metal fueled sub-critical fast reactor concepts, cooled by PbLi and PbBi, respectively, for a Fusion Transmutation of Waste Reactor (FTWR) were developed. Heat removal, radiation damage, etc. design constraints were applied to the FTWR to ensure a realistic and credible design. The standard linear stability model for critical systems was extended for evaluation of the linear stability of sub-critical systems, and the FTWR was shown to be stable to power excursions even when substantial positive fuel and coolant temperature coefficients exist. The reactor design concepts were calculated to remain subcritical for a wide range of off-normal conditions. Fuel cycle analyses were performed to evaluate the impacts of further transmutation of spent nuclear fuel on high-level and low-level waste mass flows into repositories, on the composition and toxicity of the high-level waste, on the capacity of high-level waste repositories, and on the proliferation-resistance of the high-level waste. Storage intact of LWR spent nuclear fuel, a single recycle in a LWR of the plutonium as MOX fuel, and the repeated recycle of the transuranics in critical and sub-critical fast reactors are compared. Sub-critical reactors based on both accelerator and fusion neutron sources were considered. The overall conclusions are that repeated recycling of the transuranics from spent nuclear fuel would significantly increase the capacity of high-level waste repositories per unit of nuclear energy produced, significantly increase the nuclear energy production per unit mass of uranium ore mined, significantly reduce the radio-toxicity of the waste streams per unit of nuclear energy produced, and significantly enhance the proliferation-resistance of the material stored in high-level waste repositories.

  11. Public attitudes about nuclear waste

    SciTech Connect

    Bisconti, A.S.

    1991-12-01

    There is general agreement that nuclear waste is an important national issue. It certainly is important to the industry. congress, too, gives high priority to nuclear waste disposal. In a recent pool by Reichman, Karten, Sword, 300 congressional staffers named nuclear waste disposal as the top nuclear energy-related legislative issue for Congress to address. In this paper most of the data the author discusses are from national polls that statistically represent the opinions of all American adults all across the country, as well as polls conducted in Nevada that statistically represent the opinions of all adults in that state. All the polls were by Cambridge Reports and have a margin of error of {plus_minus} 3%.

  12. Separation, Concentration, and Immobilization of Technetium and Iodine from Alkaline Supernate Waste

    SciTech Connect

    James Harvey; Michael Gula

    1998-12-07

    Development of remediation technologies for the characterization, retrieval, treatment, concentration, and final disposal of radioactive and chemical tank waste stored within the Department of Energy (DOE) complex represents an enormous scientific and technological challenge. A combined total of over 90 million gallons of high-level waste (HLW) and low-level waste (LLW) are stored in 335 underground storage tanks at four different DOE sites. Roughly 98% of this waste is highly alkaline in nature and contains high concentrations of nitrate and nitrite salts along with lesser concentrations of other salts. The primary waste forms are sludge, saltcake, and liquid supernatant with the bulk of the radioactivity contained in the sludge, making it the largest source of HLW. The saltcake (liquid waste with most of the water removed) and liquid supernatant consist mainly of sodium nitrate and sodium hydroxide salts. The main radioactive constituent in the alkaline supernatant is cesium-137, but strontium-90, technetium-99, and transuranic nuclides are also present in varying concentrations. Reduction of the radioactivity below Nuclear Regulatory Commission (NRC) limits would allow the bulk of the waste to be disposed of as LLW. Because of the long half-life of technetium-99 (2.1 x 10 5 y) and the mobility of the pertechnetate ion (TcO 4 - ) in the environment, it is expected that technetium will have to be removed from the Hanford wastes prior to disposal as LLW. Also, for some of the wastes, some level of technetium removal will be required to meet LLW criteria for radioactive content. Therefore, DOE has identified a need to develop technologies for the separation and concentration of technetium-99 from LLW streams. Eichrom has responded to this DOE-identified need by demonstrating a complete flowsheet for the separation, concentration, and immobilization of technetium (and iodine) from alkaline supernatant waste.

  13. High-risk biodegradable waste processing by alkaline hydrolysis.

    PubMed

    Kalambura, Sanja; Voća, Neven; Krička, Tajana; Sindrak, Zoran; Spehar, Ana; Kalambura, Dejan

    2011-09-01

    Biodegradable waste is by definition degraded by other living organisms. Every day, meat industry produces large amounts of a specific type of biodegradable waste called slaughterhouse waste. Traditionally in Europe, this waste is recycled in rendering plants which produce meat and bone meal and fat. However, feeding animals with meat and bone meal has been banned since the outbreaks of bovine spongiform encephalopathy (BSE). In consequence, new slaughterhouse waste processing technologies have been developed, and animal wastes have now been used for energy production. Certain parts of this waste, such as brains and spinal cord, are deemed high-risk substances, because they may be infected with prions. Their treatment is therefore possible only in strictly controlled conditions. One of the methods which seems to bear acceptable health risk is alkaline hydrolysis. This paper presents the results of an alkaline hydrolysis efficiency study. It also proposes reuse of the obtained material as organic fertiliser, as is suggested by the analytical comparison between meat and bone meal and hydrolysate.

  14. Public reactions to nuclear waste

    SciTech Connect

    Dunlap, R.E.; Kraft, M.E.; Rosa, E.A.

    1993-12-31

    For many scientists, engineers, and regulators, the public controversy over siting a repository for high-level nuclear wastes exemplifies the clash between rational scientific judgment and irrational public attitudes. Even many who are more sympathetic to public concerns about risk and management believe the controversy is exacerbated by incompatibilities between good science and public participation in regulatory decision-making. Understanding the incompatibilities, however, is crucial to managing science and technology in a democratic society and provides an important motivation to study the relationship between public opinion and nuclear waste policy. In this book, Dunlap and his colleagues present a solid base of empirical research on the subject, and the strength of the collection is the careful unraveling of social factors and context to explain the overwhelmingly negative public view of nuclear waste and its management.

  15. Nuclear waste forms for actinides.

    PubMed

    Ewing, R C

    1999-03-30

    The disposition of actinides, most recently 239Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239Pu and 237Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The "mineralogic approach" is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium.

  16. The Public and Nuclear Waste Management.

    ERIC Educational Resources Information Center

    Zinberg, Dorothy

    1979-01-01

    Discusses the public's negative attitude towards nuclear energy development. Explains the perceptions for the nuclear waste disposal problem, and the concern for the protection of the environment. (GA)

  17. The Public and Nuclear Waste Management.

    ERIC Educational Resources Information Center

    Zinberg, Dorothy

    1979-01-01

    Discusses the public's negative attitude towards nuclear energy development. Explains the perceptions for the nuclear waste disposal problem, and the concern for the protection of the environment. (GA)

  18. Calixarene crown ether solvent composition and use thereof for extraction of cesium from alkaline waste solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.; Presley, Derek J.

    2001-01-01

    A solvent composition and corresponding method for extracting cesium (Cs) from aqueous neutral and alkaline solutions containing Cs and perhaps other competing metal ions is described. The method entails contacting an aqueous Cs-containing solution with a solvent consisting of a specific class of lipophilic calix[4]arene-crown ether extractants dissolved in a hydrocarbon-based diluent containing a specific class of alkyl-aromatic ether alcohols as modifiers. The cesium values are subsequently recovered from the extractant, and the solvent subsequently recycled, by contacting the Cs-containing organic solution with an aqueous stripping solution. This combined extraction and stripping method is especially useful as a process for removal of the radionuclide cesium-137 from highly alkaline waste solutions which are also very concentrated in sodium and potassium. No pre-treatment of the waste solution is necessary, and the cesium can be recovered using a safe and inexpensive stripping process using water, dilute (millimolar) acid solutions, or dilute (millimolar) salt solutions. An important application for this invention would be treatment of alkaline nuclear tank wastes. Alternatively, the invention could be applied to decontamination of acidic reprocessing wastes containing cesium-137.

  19. The Geopolitics of Nuclear Waste.

    ERIC Educational Resources Information Center

    Marshall, Eliot

    1991-01-01

    The controversy surrounding the potential storage of nuclear waste at Yucca Mountain, Nevada, is discussed. Arguments about the stability of the site and the groundwater situation are summarized. The role of the U.S. Department of Energy and other political considerations are described. (CW)

  20. The Geopolitics of Nuclear Waste.

    ERIC Educational Resources Information Center

    Marshall, Eliot

    1991-01-01

    The controversy surrounding the potential storage of nuclear waste at Yucca Mountain, Nevada, is discussed. Arguments about the stability of the site and the groundwater situation are summarized. The role of the U.S. Department of Energy and other political considerations are described. (CW)

  1. Nuclear wastes and public trust

    SciTech Connect

    Flynn, J.; Slovic, P. |

    1993-06-01

    Citing public fear and mistrust, strong opposition to the proposed Yucca Mountain repository site, and less-than-exemplary performance by the Department of Energy (DOE), two private researchers believe present high-level radioactive waste-disposal plans may have to be scrapped. Government and the nuclear industry may have to start over. Policy makers should seek to develop new relationships with communities and states where suitable disposal sites exist. These relationships may require that citizen groups and local institutions be given unprecedented authority in locating and operating such facilities. Contrary to popular impressions, there is still time to take a new approach. The US Nuclear Regulatory Commission says present on-site storage arrangements offer a safe alternative for 100 years or more. The sense of immediate crisis and cries for immediate solutions should be calmed and a more considered strategy brought to the public debate. For starters, the researchers propose that the problems of defense waste be separated from the problems of commercial waste. They also suggest that DOE be assigned responsibility for defense waste and a new agency be created to handle high-level commercial waste.

  2. Nuclear waste policy and politics

    SciTech Connect

    Carter, L.J.

    1989-12-31

    The nation`s nuclear waste problem began in 1955 but did not draw widespread public attention until the early 1970s. It was then that the old Atomic Energy commission got in trouble by prematurely designating a site in Lyons, Kansas, as its first nuclear waste repository. This and several other false starts, coupled with the growing environmental and anti-nuclear movements, thrust the issue to the forefront of national consciousness. in the meantime, growing quantities of waste were accumulating at nuclear power plants across the country, creating mounting pressure for action. Congress acted in 1982 and again in 1987. Its 1987 decision was decisive: stop the nationwide search for a disposal site, and focus all efforts on Yucca Mountain in Nevada. Despite the clear Congressional mandate, the program is again bogged down in controversy, internal conflicts, and bureaucracy. Its future depends on a solution to these problems. And the solution involves charting some new and innovative paths around political and technical mine fields.

  3. Nuclear waste: A cancer cure?

    SciTech Connect

    1995-07-01

    In a marriage of strange bedfellows, scientists at one of the country`s most contaminated nuclear waste sites are collaborating with medical researchers to turn nuclear waste into an experimental therapy for cancer. Patients with Hodgkin`s disease and brain, ovarian, and breast cancers may be able to receive the new radiatio-based treatments in the next five to ten years. Recently, scientists at the Hanford site found a way to chemically extract a pure form of the radioisotope yttrium-90 from strontium-90, a by-product of plutonium production. Yttrium-90 is being tested in clinical trials at medical centers around the country as a treatment for various types of cancers, and the initial results are encouraging. The advantage of yttrium-90 over other radioisotopes is its short half-life.

  4. Nuclear waste forms for actinides

    PubMed Central

    Ewing, Rodney C.

    1999-01-01

    The disposition of actinides, most recently 239Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239Pu and 237Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The “mineralogic approach” is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium. PMID:10097054

  5. Plasma filtering techniques for nuclear waste remediation

    DOE PAGES

    Gueroult, Renaud; Hobbs, David T.; Fisch, Nathaniel J.

    2015-04-24

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. As a result, this advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste.

  6. Plasma filtering techniques for nuclear waste remediation.

    PubMed

    Gueroult, Renaud; Hobbs, David T; Fisch, Nathaniel J

    2015-10-30

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. This advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Nuclear waste management. Semiannual progress report, October 1983-March 1984

    SciTech Connect

    McElroy, J.L.; Powell, J.A.

    1984-06-01

    Progress in the following studies on radioactive waste management is reported: defense waste technology; Nuclear Waste Materials Characterization Center; waste isolation; and supporting studies. 58 figures, 22 tables.

  8. Anaerobic digestion of tomato processing waste: Effect of alkaline pretreatment.

    PubMed

    Calabrò, Paolo S; Greco, Rosa; Evangelou, Alexandros; Komilis, Dimitrios

    2015-11-01

    The objective of the work was to assess the effect of mild alkaline pretreatment on the anaerobic biodegradability of tomato processing waste (TPW). Experiments were carried out in duplicate BMP bottles using a pretreatment contact time of 4 and 24 h and a 1% and 5% NaOH dosage. The cumulative methane production during a 30 d period was recorded and modelled. The alkaline pretreatment did not significantly affect methane production in any of the treatments in comparison to the control. The average methane production for all runs was 320 NmL/gVS. Based on first order kinetic modelling, the alkaline pretreatment was found to slow down the rate of methanogenesis, mainly in the two reactors with the highest NaOH dosage. The biodegradability of the substrates ranged from 0.75 to 0.82 and from 0.66 to 0.72 based on two different approaches. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Bubblers Speed Nuclear Waste Processing at SRS

    ScienceCinema

    None

    2016-07-12

    At the Department of Energy's Savannah River Site, American Recovery and Reinvestment Act funding has supported installation of bubbler technology and related enhancements in the Defense Waste Processing Facility (DWPF). The improvements will accelerate the processing of radioactive waste into a safe, stable form for storage and permit expedited closure of underground waste tanks holding 37 million gallons of liquid nuclear waste.

  10. Uranium immobilization and nuclear waste

    SciTech Connect

    Duffy, C.J.; Ogard, A.E.

    1982-02-01

    Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium, plutonium, and technetium. Further, redox conditions that immobilize uranium should immobilize these elements. The mechanisms that have produced uranium ore bodies in the Earth's crust are somewhat less clear. At the temperatures of hydrothermal uranium deposits, equilibrium models are probably adequate, aqueous uranium (VI) being reduced and precipitated by interaction with ferrous-iron-bearing oxides and silicates. In lower temperature roll-type uranium deposits, overall equilibrium may not have been achieved. The involvement of sulfate-reducing bacteria in ore-body formation has been postulated, but is uncertain. Reduced sulfur species do, however, appear to be involved in much of the low temperature uranium precipitation. Assessment of the possibility of uranium transport in natural ground water is complicated because the system is generally not in overall equilibrium. For this reason, Eh measurements are of limited value. If a ground water is to be capable of reducing uranium, it must contain ions capable of reducing uranium both thermodynamically and kinetically. At present, the best candidates are reduced sulfur species.

  11. Bioprecipitation of uranium from alkaline waste solutions using recombinant Deinococcus radiodurans.

    PubMed

    Kulkarni, Sayali; Ballal, Anand; Apte, Shree Kumar

    2013-11-15

    Bioremediation of uranium (U) from alkaline waste solutions remains inadequately explored. We engineered the phoK gene (encoding a novel alkaline phosphatase, PhoK) from Sphingomonas sp. for overexpression in the radioresistant bacterium Deinococcus radiodurans. The recombinant strain thus obtained (Deino-PhoK) exhibited remarkably high alkaline phosphatase activity as evidenced by zymographic and enzyme activity assays. Deino-PhoK cells could efficiently precipitate uranium over a wide range of input U concentrations. At low uranyl concentrations (1 mM), the strain precipitated >90% of uranium within 2h while a high loading capacity of around 10.7 g U/g of dry weight of cells was achieved at 10 mM U concentration. Uranium bioprecipitation by Deino-PhoK cells was not affected in the presence of Cs and Sr, commonly present in intermediate and low level liquid radioactive waste, or after exposure to very high doses of ionizing radiation. Transmission electron micrographs revealed the extracellular nature of bioprecipitated U, while X-ray diffraction and fluorescence analysis identified the precipitated uranyl phosphate species as chernikovite. When immobilized into calcium alginate beads, Deino-PhoK cells efficiently removed uranium, which remained trapped in beads, thus accomplishing physical separation of precipitated uranyl phosphate from solutions. The data demonstrate superior ability of Deino-PhoK, over earlier reported strains, in removal of uranium from alkaline solutions and its potential use in bioremediation of nuclear and other waste. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Magnetic fusion driventransmutation of nuclear waste (FTW)

    SciTech Connect

    Peng, Yueng Kay Martin; Cheng, E.T.

    1993-01-01

    The possibility of magnetic Fusion driven Transmutation of Waste (FTW) was revisted and discussed recently. Nuclear wastes include all transuranium elements: Pu isotopes, minor actinides separated from the spent fission fuel, and fissile products. Elimination of thse long-life nuclear wastes is necessary for the long-term viability of fission power. A Small Business Innovative Research program has been initiated under the leadership of TSI Research to examine the efficacy of fusion transmutation of waste utilizing small fusion drivers.

  13. Global Nuclear Energy Partnership Waste Treatment Baseline

    SciTech Connect

    Dirk Gombert; William Ebert; James Marra; Robert Jubin; John Vienna

    2008-05-01

    The Global Nuclear Energy Partnership program (GNEP) is designed to demonstrate a proliferation-resistant and sustainable integrated nuclear fuel cycle that can be commercialized and used internationally. Alternative stabilization concepts for byproducts and waste streams generated by fuel recycling processes were evaluated and a baseline of waste forms was recommended for the safe disposition of waste streams. Waste forms are recommended based on the demonstrated or expected commercial practicability and technical maturity of the processes needed to make the waste forms, and performance of the waste form materials when disposed. Significant issues remain in developing technologies to process some of the wastes into the recommended waste forms, and a detailed analysis of technology readiness and availability may lead to the choice of a different waste form than what is recommended herein. Evolving regulations could also affect the selection of waste forms.

  14. Recycling of chemicals from alkaline waste generated during preparation of UO 3 microspheres by sol-gel process

    NASA Astrophysics Data System (ADS)

    Kumar, Ashok; Vittal Rao, T. V.; Mukerjee, S. K.; Vaidya, V. N.

    2006-05-01

    Internal gelation process, one of the sol-gel processes for nuclear fuel fabrication, offers many advantages over conventional powder pellet route. However, one of the limitation of the process is generation of large volume of alkaline liquid waste containing hexamethylenetetramine, urea, ammonium nitrate, ammonium hydroxide etc. Presence of ammonium nitrate with hexamethylenetetramine and urea presents a fire hazard which prevents direct disposal of the waste as well as its recycle by evaporation. The paper describes the studies carried out to suitably process the waste. Nitrate was removed from the waste by passing through Dowex 1 × 4 anion exchange resin in OH - form. 1.0 M NaOH was used to regenerate the resin. The nitrate-free waste was further treated to recover and recycle hexamethylenetetramine, urea and ammonium hydroxide for preparation of UO 3 microspheres. The quality of the microspheres obtained was satisfactory. An optimized flow sheet for processing of the waste solution has been suggested.

  15. Questioning nuclear waste substitution: a case study.

    PubMed

    Marshall, Alan

    2007-03-01

    This article looks at the ethical quandaries, and their social and political context, which emerge as a result of international nuclear waste substitution. In particular it addresses the dilemmas inherent within the proposed return of nuclear waste owned by Japanese nuclear companies and currently stored in the United Kingdom. The UK company responsible for this waste, British Nuclear Fuels Limited (BNFL), wish to substitute this high volume intermediate-level Japanese-owned radioactive waste for a much lower volume of much more highly radioactive waste. Special focus is given to ethical problems that they, and the UK government, have not wished to address as they move forward with waste substitution. The conclusion is that waste substitution can only be considered an ethical practice if a set of moderating conditions are observed by all parties. These conditions are listed and, as of yet, they are not being observed.

  16. Nuclear waste disposal: Gambling on Yucca Mountain

    SciTech Connect

    Ginsburg, S.

    1995-05-01

    This document describes the historical aspects of nuclear energy ,nuclear weapons usage, and development of the nuclear bureaucracy in the United States, and discusses the selection and siting of Yucca Mountain, Nevada for a federal nuclear waste repository. Litigation regarding the site selection and resulting battles in the political arena and in the Nevada State Legislature are also presented. Alternative radioactive waste disposal options, risk assessments of the Yucca Mountain site, and logistics regarding the transportation and storage of nuclear waste are also presented. This document also contains an extensive bibliography.

  17. Nuclear Waste Disposal: Alternatives to Yucca Mountain

    DTIC Science & Technology

    2009-02-06

    permanent high-level nuclear waste repository in 1987, following years of controversy over the site -selection process. Over the strenuous objections of...contending in an issue statement that he and now-Vice President Biden “do not believe that Yucca Mountain is a suitable site .” Under the current nuclear ...to Yucca Mountain would be indefinite on- site storage of nuclear waste at reactor sites and other nuclear facilities. Private central storage

  18. Developing and testing an alkaline-side solvent extraction process for technetium separation from tank waste.

    SciTech Connect

    Leonard, R.A.; Conner, C.; Liberatore, M.W.; Bonnesen, P.V.; Moyer, B.A.; Presley, D.J.; Lumetta, G.J.

    1997-12-05

    Engineering development and testing of the SRTALK solvent extraction process are discussed in this paper. This process provides a way to carry out alkaline-side removal and recovery of technetium in the form of pertechnetate anion from nuclear waste tanks within the DOE complex. The SRTALK extractant consists of a crown ether, bis-4,4'(5')[(tert-butyl)cyclohexano] -18-crown-6, in a modifier, tributyl phosphate, and a diluent, Isopar{reg_sign}L. The SRTALK flowsheet given here separates technetium from the waste and concentrates it by a factor often to minimize the load on the downstream evaporator for the technetium effluent. In this work, we initially generated and correlated the technetium extraction data, measured the dispersion number for various processing conditions, and determined hydraulic performance in a single-stage 2-cm centrifugal contactor. Then we used extraction-factor analysis, single-stage contactor tests, and stage-to-stage process calculations to develop a SRTALK flowsheet. Key features of the flowsheet are (1) a low organic-to-aqueous (O/A) flow ratio in the extraction section and a high O/A flow ratio in the strip section concentrate the technetium and (2) the use of a scrub section to reduce the salt load in the concentrated technetium effluent. Finally, the SRTALK process was evaluated in a multistage test using a synthetic tank waste. This test was very successful. Initial tests with actual waste from the Hanford nuclear waste tanks show the same technetium extractability as determined with the synthetic waste feed. Therefore, technetium removal from actual tank wastes should also work well using the SRTALK process.

  19. Concept for Underground Disposal of Nuclear Waste

    NASA Technical Reports Server (NTRS)

    Bowyer, J. M.

    1987-01-01

    Packaged waste placed in empty oil-shale mines. Concept for disposal of nuclear waste economically synergistic with earlier proposal concerning backfilling of oil-shale mines. New disposal concept superior to earlier schemes for disposal in hard-rock and salt mines because less uncertainty about ability of oil-shale mine to contain waste safely for millenium.

  20. Concept for Underground Disposal of Nuclear Waste

    NASA Technical Reports Server (NTRS)

    Bowyer, J. M.

    1987-01-01

    Packaged waste placed in empty oil-shale mines. Concept for disposal of nuclear waste economically synergistic with earlier proposal concerning backfilling of oil-shale mines. New disposal concept superior to earlier schemes for disposal in hard-rock and salt mines because less uncertainty about ability of oil-shale mine to contain waste safely for millenium.

  1. Enhancement of accelerated carbonation of alkaline waste residues by ultrasound.

    PubMed

    Araizi, Paris K; Hills, Colin D; Maries, Alan; Gunning, Peter J; Wray, David S

    2016-04-01

    The continuous growth of anthropogenic CO2 emissions into the atmosphere and the disposal of hazardous wastes into landfills present serious economic and environmental issues. Reaction of CO2 with alkaline residues or cementitius materials, known as accelerated carbonation, occurs rapidly under ambient temperature and pressure and is a proven and effective process of sequestering the gas. Moreover, further improvement of the reaction efficiency would increase the amount of CO2 that could be permanently sequestered into solid products. This paper examines the potential of enhancing the accelerated carbonation of air pollution control residues, cement bypass dust and ladle slag by applying ultrasound at various water-to-solid (w/s) ratios. Experimental results showed that application of ultrasound increased the CO2 uptake by up to four times at high w/s ratios, whereas the reactivity at low water content showed little change compared with controls. Upon sonication, the particle size of the waste residues decreased and the amount of calcite precipitates increased. Finally, the sonicated particles exhibited a rounded morphology when observed by scanning electron microscopy.

  2. OCRWM International Cooperation in Nuclear Waste Management

    SciTech Connect

    Jackson, R.; Levich, R.; Strahl, J.

    2002-02-27

    With the implementation of nuclear power as a major energy source, the United States is increasingly faced with the challenges of safely managing its inventory of spent nuclear materials. In 2002, with 438 nuclear power facilities generating electrical energy in 31 nations around the world, the management of radioactive material including spent nuclear fuel and high-level radioactive waste, is an international concern. Most of the world's nuclear nations maintain radioactive waste management programs and have generally accepted deep geologic repositories as the long-term solution for disposal of spent nuclear fuel and high-level radioactive waste. Similarly, the United States is evaluating the feasibility of deep geologic disposal at Yucca Mountain, Nevada. This project is directed by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management (OCRWM), which has responsibility for managing the disposition of spent nuclear fuel produced by commercial nuclear power facilities along with U.S. government-owned spent nuclear fuel and high-level radioactive waste. Much of the world class science conducted through the OCRWM program was enhanced through collaboration with other nations and international organizations focused on resolving issues associated with the disposition of spent nuclear fuel and high-level radioactive waste.

  3. Nuclear waste disposal educational forum

    SciTech Connect

    Not Available

    1982-10-18

    In keeping with a mandate from the US Congress to provide opportunities for consumer education and information and to seek consumer input on national issues, the Department of Energy's Office of Consumer Affairs held a three-hour educational forum on the proposed nuclear waste disposal legislation. Nearly one hundred representatives of consumer, public interest, civic and environmental organizations were invited to attend. Consumer affairs professionals of utility companies across the country were also invited to attend the forum. The following six papers were presented: historical perspectives; status of legislation (Senate); status of legislation (House of Representatives); impact on the legislation on electric utilities; impact of the legislation on consumers; implementing the legislation. All six papers have been abstracted and indexed for the Energy Data Base.

  4. Nuclear waste storage in Gabon

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The geological record of Oklo, Republic of Gabon, may provide clues to the best and safest methods of storing radioactive waste products. A group of isotope geochemists from the Los Alamos National Laboratory has begun a field and laboratory study of natural geologic nuclear reactors in equatorial Africa to assess the distribution of radioactive products in the ground. The project requires a good deal of study, and the early results must be considered preliminary; nonetheless, they are very promising. T. Benjamin of Los Alamos reported recently at a meeting of the Geological Society of Washington that radionuclides did not appear to migrate great distances from several of the natural reactors at the Oklo deposit.

  5. Managing Nuclear Waste: Options Considered

    SciTech Connect

    DOE

    2002-05-02

    Starting in the 1950s, U.S. scientists began to research ways to manage highly radioactive materials accumulating at power plants and other sites nationwide. Long-term surface storage of these materials poses significant potential health, safety, and environmental risks. Scientists studied a broad range of options for managing spent nuclear fuel and high-level radioactive waste. The options included leaving it where it is, disposing of it in various ways, and making it safer through advanced technologies. International scientific consensus holds that these materials should eventually be disposed of deep underground in what is called a geologic repository. In a recent special report, the National Academy of Sciences summarized the various studies and emphasized that geologic disposal is ultimately necessary.

  6. Managing nuclear waste from power plants

    SciTech Connect

    Keeney, R.L.; Winterfeldt, D. von

    1994-02-01

    National strategies to manage nuclear waste from commercial nuclear power plants are analyzed and compared. The current strategy is to try to operate a repository at Yucca Mountain, Nevada, to dispose storage at a centralized facility or next to nuclear power plants. If either of these is pursued now, the analysis assumes that a repository will be built in 2100 for waste not subsequently put to use. The analysis treats various uncertainties: whether a repository at Yucca Mountain would be licensed, possible theft and misuse of the waste, innovations in repository design and waste management, the potential availability of a cancer cure by 2100, and possible future uses of nuclear waste. The objectives used to compare alternatives include concerns for health and safety, environmental and socioeconomic impacts, and direct economic costs, as well as equity concerns (geographical, intergenerational, and procedural), indirect economic costs, as well as equity concerns (geographical, intergenerational, and procedural), indirect economic costs to electricity ratepayers, federal government responsibility to manage nuclear waste, and implications of theft and misuse of nuclear waste. The analysis shows that currently building an underground repository at Yucca Mountain is inferior to other available strategies by the equivalent of $10,000 million to $50,000 million. This strongly suggests that this policy should be reconsidered. A more detailed analysis using the framework presented would help to define a new national policy to manage nuclear waste. 36 refs., 3 figs., 17 tabs.

  7. SRNL CRP progress report [Development of Melt Processed Ceramics for Nuclear Waste Immobilization

    SciTech Connect

    Amoroso, J.; Marra, J.

    2014-10-02

    A multi-phase ceramic waste form is being developed at the Savannah River National Laboratory (SRNL) for treatment of secondary waste streams generated by reprocessing commercial spent nuclear. The envisioned waste stream contains a mixture of transition, alkali, alkaline earth, and lanthanide metals. Ceramic waste forms are tailored (engineered) to incorporate waste components as part of their crystal structure based on knowledge from naturally found minerals containing radioactive and non-radioactive species similar to the radionuclides of concern in wastes from fuel reprocessing. The ability to tailor ceramics to mimic naturally occurring crystals substantiates the long term stability of such crystals (ceramics) over geologic timescales of interest for nuclear waste immobilization [1]. A durable multiphase ceramic waste form tailored to incorporate all the waste components has the potential to broaden the available disposal options and thus minimize the storage and disposal costs associated with aqueous reprocessing.

  8. Nuclear Waste Management. Semiannual progress report, October 1984-March 1985

    SciTech Connect

    McElroy, J.L.; Powell, J.A.

    1985-06-01

    Progress reports are presented for the following studies on radioactive waste management: defense waste technology; nuclear waste materials characterization center; and supporting studies. 19 figs., 29 tabs.

  9. Nuclear Waste Management. Semiannual progress report, April 1984-September 1984

    SciTech Connect

    McElroy, J.L.; Powell, J.A.

    1984-12-01

    Progress in the following studies on radioactive waste management is reported: defense waste technology; Nuclear Waste Materials Characterization Center; and supporting studies. 33 figures, 13 tables.

  10. Plasma Mass Filters For Nuclear Waste Reprocessing

    SciTech Connect

    Fetterman, Abraham J.; Fisch, Nathaniel J.

    2011-05-01

    Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

  11. Plasma Mass Filters For Nuclear Waste Reprocessing

    SciTech Connect

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-05-26

    Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

  12. Science, Society, and America's Nuclear Waste: Nuclear Waste, Unit 1. Teacher Guide. Second Edition.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

    This guide is Unit 1 of the four-part series Science, Society, and America's Nuclear Waste produced by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management. The goal of this unit is to help students establish the relevance of the topic of nuclear waste to their everyday lives and activities. Particular attention is…

  13. A parallel-plate electrochemical reactor model for the destruction of nitrate and nitrite in alkaline waste solutions

    SciTech Connect

    Coleman, D.H.; White, R.E.; Hobbs, D.T.

    1995-04-01

    The electrochemical treatment of nuclear waste is the subject of much current interest. After radioactive decontamination, the liquid waste from nuclear fuel processing still contains many hazardous substances, among them nitrate and nitrite. A parallel-plate electrochemical reactor model with multiple reactions at both electrodes and anolyte and catholyte recirculation tanks was modeled for the electrochemical destruction of nitrate and nitrite species in an alkaline solution. The model can be used to predict electrochemical reaction current efficiencies and outlet concentrations of species from the reactor, given inlet feed conditions and cell operating conditions. Also, predictions are made for off-gas composition and liquid-phase composition in the recirculation tanks. The results of case studies at different applied potentials are shown here. At lower applied potentials, the model predictions show that the destruction process is more energy efficient, but the time required to destroy a given amount of waste is increased.

  14. Nuclear fuel cycle waste stream immobilization with cermets for improved thermal properties and waste consolidation

    NASA Astrophysics Data System (ADS)

    Ortega, Luis H.; Kaminski, Michael D.; Zeng, Zuotao; Cunnane, James

    2013-07-01

    In the pursuit of methods to improve nuclear waste form thermal properties and combine potential nuclear fuel cycle wastes, a bronze alloy was combined with an alkali, alkaline earth metal bearing ceramic to form a cermet. The alloy was prepared from copper and tin (10 mass%) powders. Pre-sintered ceramic consisting of cesium, strontium, barium and rubidium alumino-silicates was mixed with unalloyed bronze precursor powders and cold pressed to 300 × 103 kPa, then sintered at 600 °C and 800 °C under hydrogen. Cermets were also prepared that incorporated molybdenum, which has a limited solubility in glass, under similar conditions. The cermet thermal conductivities were seven times that of the ceramic alone. These improved thermal properties can reduce thermal gradients within the waste forms thus lowering internal temperature gradients and thermal stresses, allowing for larger waste forms and higher waste loadings. These benefits can reduce the total number of waste packages necessary to immobilize a given amount of high level waste and immobilize troublesome elements.

  15. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Advisory Committee on Nuclear Waste. 1.18 Section 1.18... Panels, Boards, and Committees § 1.18 Advisory Committee on Nuclear Waste. The Advisory Committee on Nuclear Waste (ACNW) provides advice to the Commission on all aspects of nuclear waste management, as...

  16. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Advisory Committee on Nuclear Waste. 1.18 Section 1.18... Panels, Boards, and Committees § 1.18 Advisory Committee on Nuclear Waste. The Advisory Committee on Nuclear Waste (ACNW) provides advice to the Commission on all aspects of nuclear waste management, as...

  17. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Advisory Committee on Nuclear Waste. 1.18 Section 1.18... Panels, Boards, and Committees § 1.18 Advisory Committee on Nuclear Waste. The Advisory Committee on Nuclear Waste (ACNW) provides advice to the Commission on all aspects of nuclear waste management, as...

  18. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Advisory Committee on Nuclear Waste. 1.18 Section 1.18... Panels, Boards, and Committees § 1.18 Advisory Committee on Nuclear Waste. The Advisory Committee on Nuclear Waste (ACNW) provides advice to the Commission on all aspects of nuclear waste management, as...

  19. Solid wastes from nuclear power production.

    PubMed Central

    Soule, H F

    1978-01-01

    Radioactivity in nuclear power effluents is negligible compared to that in retained wastes to be disposed of as solids. Two basic waste categories are those for which shallow disposal is accepted and those for which more extreme isolation is desired. The latter includes "high level" wastes and others contaminated with radionuclides with the unusual combined properties of long radioactive half-life and high specific radiotoxicity. The favored method for extreme isolation is emplacement in a deep stable geologic formation. Necessary technologies for waste treatment and disposal are considered available. The present program to implement these technologies is discussed, including the waste management significance of current policy on spent nuclear fuel reprocessing. Recent difficulties with shallow disposal of waste are summarized. PMID:738244

  20. Nuclear waste: distant and expensive mirage

    SciTech Connect

    2008-08-15

    The situation in the U.S. regarding the disposal of nuclear waste is briefly summarized. Current estimates are that the site will not begin operation before 2020, and that the cost will be $96 billion, which includes construction, waste transport, operation through 2133, and closure of the facility. The Department of Energy is also considering whether more disposal sites might be needed.

  1. Nuclear Waste Primer: A Handbook for Citizens.

    ERIC Educational Resources Information Center

    Weber, Isabelle P.; Wiltshire, Susan D.

    This publication was developed with the intention of offering the nonexpert a concise, balanced introduction to nuclear waste. It outlines the dimensions of the problem, discussing the types and quantities of waste. Included are the sources, types, and hazards of radiation, and some of the history, major legislation, and current status of both…

  2. Nuclear waste management: storage and disposal aspects

    SciTech Connect

    Patterson, B.D.; Dave, S.A.; O'Connell, W.J.

    1980-01-01

    Long-term disposal of nuclear wastes must resolve difficulties arising chiefly from the potential for contamination of the environment and the risk of misuse. Alternatives available for storage and disposal of wastes are examined in this overview paper. Guidelines and criteria which may govern in the development of methods of disposal are discussed.

  3. Nuclear Waste Primer: A Handbook for Citizens.

    ERIC Educational Resources Information Center

    Weber, Isabelle P.; Wiltshire, Susan D.

    This publication was developed with the intention of offering the nonexpert a concise, balanced introduction to nuclear waste. It outlines the dimensions of the problem, discussing the types and quantities of waste. Included are the sources, types, and hazards of radiation, and some of the history, major legislation, and current status of both…

  4. Overview assessment of nuclear-waste management

    NASA Astrophysics Data System (ADS)

    Burton, B. W.; Gutschick, V. P.; Perkins, B. A.; Reynolds, C. L.; Rodgers, J. C.; Steger, J. G.; Thompson, T. K.; Trocki, L. K.; Wewerka, E. M.; Wheeler, M. L.

    1982-08-01

    The environmental control technologies associated with Department of Energy nuclear waste management programs were reviewed and the most urgent problems requiring further action or follow up were identified. In order of decreasing importance they are: (1) shallow land disposal technology development; (2) active uranium mill tailings piles; (3) uranium mine dewatering; (4) site decommissioning; (5) exhumation/treatment of transuranic waste at Idaho National Engineering Laboratory; (6) uranium mine spoils; and (7) medical/institutional wastes.

  5. Natural analogues of nuclear waste glass corrosion.

    SciTech Connect

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  6. Radiation Effects in Nuclear Waste Materials

    SciTech Connect

    Weber, William J.

    2005-09-30

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials.

  7. Radiation Effects in Nuclear Waste Materials

    SciTech Connect

    Weber, William J.

    2005-06-01

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials.

  8. Doing the impossible: Recycling nuclear waste

    ScienceCinema

    None

    2016-07-12

    A Science Channel feature explores how Argonne techniques could be used to safely reduce the amount of radioactive waste generated by nuclear power—the most plentiful carbon-neutral energy source. Read more at http://www.anl.gov/Media_Center/ArgonneNow/Fall_2009/nuclear.html

  9. Strontium and Actinide Separations from High Level Nuclear Waste Solutions using Monosodium Titanate - Actual Waste Testing

    SciTech Connect

    Peters, T.B.; Barnes, M.J.; Hobbs,D.T.; Walker, D.D.; Fondeur, F.F.; Norato, M.A.; Pulmano, R.L.; Fink, S.D.

    2005-11-01

    Pretreatment processes at the Savannah River Site will separate {sup 90}Sr, alpha-emitting and radionuclides (i.e., actinides) and {sup 137}Cs prior to disposal of the high-level nuclear waste. Separation of {sup 90}Sr and alpha-emitting radionuclides occurs by ion exchange/adsorption using an inorganic material, monosodium titanate (MST). Previously reported testing with simulants indicates that the MST exhibits high selectivity for strontium and actinides in high ionic strength and strongly alkaline salt solutions. This paper provides a summary of data acquired to measure the performance of MST to remove strontium and actinides from actual waste solutions. These tests evaluated the effects of ionic strength, mixing, elevated alpha activities, and multiple contacts of the waste with MST. Tests also provided confirmation that MST performs well at much larger laboratory scales (300-700 times larger) and exhibits little affinity for desorption of strontium and plutonium during washing.

  10. Nuclear waste incineration technology status

    SciTech Connect

    Ziegler, D.L.; Lehmkuhl, G.D.; Meile, L.J.

    1981-07-15

    The incinerators developed and/or used for radioactive waste combustion are discussed and suggestions are made for uses of incineration in radioactive waste management programs and for incinerators best suited for specific applications. Information on the amounts and types of radioactive wastes are included to indicate the scope of combustible wastes being generated and in existence. An analysis of recently developed radwaste incinerators is given to help those interested in choosing incinerators for specific applications. Operating information on US and foreign incinerators is also included to provide additional background information. Development needs are identified for extending incinerator applications and for establishing commercial acceptance.

  11. Nuclear waste package fabricated from concrete

    SciTech Connect

    Pfeiffer, P.A.; Kennedy, J.M.

    1987-03-01

    After the United States enacted the Nuclear Waste Policy Act in 1983, the Department of Energy must design, site, build and operate permanent geologic repositories for high-level nuclear waste. The Department of Energy has recently selected three sites, one being the Hanford Site in the state of Washington. At this particular site, the repository will be located in basalt at a depth of approximately 3000 feet deep. The main concern of this site, is contamination of the groundwater by release of radionuclides from the waste package. The waste package basically has three components: the containment barrier (metal or concrete container, in this study concrete will be considered), the waste form, and other materials (such as packing material, emplacement hole liners, etc.). The containment barriers are the primary waste container structural materials and are intended to provide containment of the nuclear waste up to a thousand years after emplacement. After the containment barriers are breached by groundwater, the packing material (expanding sodium bentonite clay) is expected to provide the primary control of release of radionuclide into the immediate repository environment. The loading conditions on the concrete container (from emplacement to approximately 1000 years), will be twofold; (1) internal heat of the high-level waste which could be up to 400/sup 0/C; (2) external hydrostatic pressure up to 1300 psi after the seepage of groundwater has occurred in the emplacement tunnel. A suggested container is a hollow plain concrete cylinder with both ends capped. 7 refs.

  12. The disposal of nuclear waste in space

    NASA Technical Reports Server (NTRS)

    Burns, R. E.

    1978-01-01

    The important problem of disposal of nuclear waste in space is addressed. A prior study proposed carrying only actinide wastes to space, but the present study assumes that all actinides and all fission products are to be carried to space. It is shown that nuclear waste in the calcine (oxide) form can be packaged in a container designed to provide thermal control, radiation shielding, mechanical containment, and an abort reentry thermal protection system. This package can be transported to orbit via the Space Shuttle. A second Space Shuttle delivers an oxygen-hydrogen orbit transfer vehicle to a rendezvous compatible orbit and the mated OTV and waste package are sent to the preferred destination. Preferred locations are either a lunar crater or a solar orbit. Shuttle traffic densities (which vary in time) are given and the safety of space disposal of wastes discussed.

  13. The disposal of nuclear waste in space

    NASA Technical Reports Server (NTRS)

    Burns, R. E.

    1978-01-01

    The important problem of disposal of nuclear waste in space is addressed. A prior study proposed carrying only actinide wastes to space, but the present study assumes that all actinides and all fission products are to be carried to space. It is shown that nuclear waste in the calcine (oxide) form can be packaged in a container designed to provide thermal control, radiation shielding, mechanical containment, and an abort reentry thermal protection system. This package can be transported to orbit via the Space Shuttle. A second Space Shuttle delivers an oxygen-hydrogen orbit transfer vehicle to a rendezvous compatible orbit and the mated OTV and waste package are sent to the preferred destination. Preferred locations are either a lunar crater or a solar orbit. Shuttle traffic densities (which vary in time) are given and the safety of space disposal of wastes discussed.

  14. Are there options for nuclear waste?

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The problems of storage of nuclear wastes are reaching crisis proportions. Although conceding that a measure of the crises has been caused by the ‘enormous emotion’ of ‘protesting green ecologists,’ (ISR, Interdisciplinary Science Reviews, 5(4), 1980), the bottom line is that nuclear wastes have been and continue to be dumped into the oceans and scattered in leaking and leakable containers on the surface. There is a fear among members of the nuclear engineering community that the U.S., under recent government restrictions, has placed itself in a compromising position on the development of nuclear power facilities. One area of concern is that of nuclear waste disposal. Other countries are subject to the same problems and fears. For example, in the Federal Republic of Germany the term ‘Enstorgungszentrum’ has been coined to describe the total process of reprocessing and disposal of spent nuclear fuel elements. The concern is that spent fuel continues to accumulate because restrictions and laws have affected efforts to resolve the problems of reprocessing and disposal. Right now the environment is subject to damage from the inadequate storage practices of the past. Geoscientists working on the problem of waste disposal await the answers to questions about the projected quantity of waste to be disposed. The options to be explored depend on the volumes to be handled.

  15. Nuclear Waste--Physics and Policy

    NASA Astrophysics Data System (ADS)

    Ahearne, John H.

    1996-03-01

    Managing and disposing of radioactive waste are major policy and financial issues in the United States and many other countries. Low-level waste sites, once thought to be possible in many states, remain fixed at the few sites that have been operating for decades. High-level waste remains at former nuclear weapons facilities and at nuclear power plants, and the DOE estimates a repository is unlikely before 2010, at the earliest. Physics and chemistry issues relate to criticality, plutonium loading in glass, leach rates, and diffusion. The public policy issues concern non-proliferation, states' rights, stakeholder participation, and nuclear power. Cleaning up the legacy of cold war driven nuclear weapons production is estimated to cost at least $250 billion and take three-quarters of a century. Some possible steps towards resolution of these issues will be described.

  16. SORPTION OF URANIUM, PLUTONIUM AND NEPTUNIUM ONTO SOLIDS PRESENT IN HIGH CAUSTIC NUCLEAR WASTE STORAGE TANKS

    SciTech Connect

    Oji, L; Bill Wilmarth, B; David Hobbs, D

    2008-05-30

    Solids such as granular activated carbon, hematite and sodium phosphates, if present as sludge components in nuclear waste storage tanks, have been found to be capable of precipitating/sorbing actinides like plutonium, neptunium and uranium from nuclear waste storage tank supernatant liqueur. Thus, the potential may exists for the accumulation of fissile materials in such nuclear waste storage tanks during lengthy nuclear waste storage and processing. To evaluate the nuclear criticality safety in a typical nuclear waste storage tank, a study was initiated to measure the affinity of granular activated carbon, hematite and anhydrous sodium phosphate to sorb plutonium, neptunium and uranium from alkaline salt solutions. Tests with simulated and actual nuclear waste solutions established the affinity of the solids for plutonium, neptunium and uranium upon contact of the solutions with each of the solids. The removal of plutonium and neptunium from the synthetic salt solution by nuclear waste storage tank solids may be due largely to the presence of the granular activated carbon and transition metal oxides in these storage tank solids or sludge. Granular activated carbon and hematite also showed measurable affinity for both plutonium and neptunium. Sodium phosphate, used here as a reference sorbent for uranium, as expected, exhibited high affinity for uranium and neptunium, but did not show any measurable affinity for plutonium.

  17. Inorganic ion exchangers for nuclear waste remediation

    SciTech Connect

    Clearfield, A.; Bortun, A.; Bortun, L.; Behrens, E.

    1997-10-01

    The objective of this work is to provide a broad spectrum of inorganic ion exchangers that can be used for a range of applications and separations involving remediation of groundwater and tank wastes. The authors intend to scale-up the most promising exchangers, through partnership with AlliedSignal Inc., to provide samples for testing at various DOE sites. While much of the focus is on exchangers for removal of Cs{sup +} and Sr{sup 2+} from highly alkaline tank wastes, especially at Hanford, the authors have also synthesized exchangers for acid wastes, alkaline wastes, groundwater, and mercury, cobalt, and chromium removal. These exchangers are now available for use at DOE sites. Many of the ion exchangers described here are new, and others are improved versions of previously known exchangers. They are generally one of three types: (1) layered compounds, (2) framework or tunnel compounds, and (3) amorphous exchangers in which a gel exchanger is used to bind a fine powder into a bead for column use. Most of these exchangers can be regenerated and used again.

  18. Effect of pH on the destruction of complexants with ozone in Hanford nuclear waste

    SciTech Connect

    Winters, W.I.

    1981-06-01

    Chemical processing of nuclear waste at Hanford has generated some waste solutions with high concentration (0.1 to 0.5M) of N-(hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), and other organic complexing agents. These complexants must be destroyed bacause they affect radionuclide migration in soils, waste concentration, radionuclide removal, and other waste storage and processing considerations. Previous studies on actual waste solutions demonstrated that preozonation of the alkaline waste significantly improved radionuclide removal. A series of bench-scale experiments using synthetic waste has been performed to determine the optimum pH for most efficient ozone destruction of EDTA. Ozonation of EDTA in synthetic waste was carried out over the pH range of 1 to 14. Potential catalytic materials were examined at different pH levels. The EDTA-ozone reaction rates and stoichiometric requirements were compared and evaluated for the varying conditions.

  19. Science, Society, and America's Nuclear Waste: The Nuclear Waste Policy Act, Unit 3. Teacher Guide. Second Edition.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

    This guide is Unit 3 of the four-part series, Science, Society, and America's Nuclear Waste, produced by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management. The goal of this unit is to identify the key elements of the United States' nuclear waste dilemma and introduce the Nuclear Waste Policy Act and the role of the…

  20. Microstructural characterization of nuclear-waste ceramics

    SciTech Connect

    Ryerson, F.J.; Clarke, D.R.

    1982-09-22

    Characterization of nuclear waste ceramics requires techniques possessing high spatial and x-ray resolution. XRD, SEM, electron microprobe, TEM and analytical EM techniques are applied to ceramic formulations designed to immobilize both commercial and defense-related reactor wastes. These materials are used to address the strengths and limitations of the techniques above. An iterative approach combining all these techniques is suggested. 16 figures, 2 tables.

  1. Salvaging of nuclear waste by nuclear-optical converters

    NASA Astrophysics Data System (ADS)

    Karelin, A. V.; Shirokov, R. V.

    2007-06-01

    In modern conditions of power consumption growing in Russia, apparently, it is difficult to find alternative to further development of nuclear power engineering. The negative party of nuclear power engineering is the spent fuel of nuclear reactors (radioactive waste). The gaseous and fluid radioactive waste furbished of highly active impurity, dumps in atmosphere or pools. The highly active fluid radioactive waste stores by the way of saline concentrates in special tanks in surface layers of ground, above the level of groundwaters. A firm radioactive waste bury in pods from a stainless steel in underground workings, salt deposits, at the bottom of oceans. However this problem can be esteemed in a positive direction, as irradiation is a hard radiation, which one can be used as a power source in nuclear - optical converters with further conversion of optical radiation into the electric power with the help of photoelectric converters. Thus waste at all do not demand special processing and exposure in temporary storehouses. And the electricity can be worked out in a constant mode within many years practically without gang of a stimulus source, if a level of a residual radioactivity and the half-lives of component are high enough.

  2. Radiation Effects in Nuclear Waste Materials

    SciTech Connect

    Weber, William J.; Corrales, L. Rene; Ness, Nancy J.; Williford, Ralph E.; Heinisch, Howard L.; Thevuthasan, Suntharampillai; Icenhower, Jonathan P.; McGrail, B. Peter; Devanathan, Ramaswami; Van Ginhoven, Renee M.; Song, Jakyoung; Park, Byeongwon; Jiang, Weilin; Begg, Bruce D.; Birtcher, R. B.; Chen, X.; Conradson, Steven D.

    2000-10-02

    Radiation effects from the decay of radionuclides may impact the long-term performance and stability of nuclear waste forms and stabilized nuclear materials. In an effort to address these concerns, the objective of this project was the development of fundamental understanding of radiation effects in glasses and ceramics, particularly on solid-state radiation effects and their influence on aqueous dissolution kinetics. This study has employed experimental, theoretical and computer simulation methods to obtain new results and insights into radiation damage processes and to initiate the development of predictive models. Consequently, the research that has been performed under this project has significant implications for the High-Level Waste and Nuclear Materials focus areas within the current DOE/EM mission. In the High-Level Waste (HLW) focus area, the results of this research could lead to improvements in the understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials focus area, the results of this research could lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. Ultimately, this research could result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials.

  3. Advances in processing nuclear waste glasses

    SciTech Connect

    Plodinec, M J

    1988-01-01

    The vitrification of nuclear waste glasses is presenting unique challenges to glass technologists. On the one hand, the composition of the most important constituent of the glass batch/--/the waste/--/may vary widely. On the other hand, the vitrification process itself must be tightly controlled to ensure product quality, public safety, and process reliability. This has led to several important developments in waste vitrification technology, all aimed at improving process control. These include use of process models, use of artificial intelligence techniques, and improved control and measurement of glass redox. 19 refs., 2 figs., 2 tabs.

  4. Chemical aspects of nuclear waste treatment

    SciTech Connect

    Bond, W. D.

    1980-01-01

    The chemical aspects of the treatment of gaseous, liquid, and solid wastes are discussed in overview. The role of chemistry and the chemical reactions in waste treatment are emphasized. Waste treatment methods encompass the chemistry of radioactive elements from every group of the periodic table. In most streams, the radioactive elements are present in relatively low concentrations and are often associated with moderately large amounts of process reagents, or materials. In general, it is desirable that waste treatment methods are based on chemistry that is selective for the concentration of radionuclides and does not require the addition of reagents that contribute significantly to the volume of the treated waste. Solvent extraction, ion exchange, and sorbent chemistry play a major role in waste treatment because of the high selectivity provided for many radionuclides. This paper deals with the chemistry of the onsite treatment methods that is typically used at nuclear installations and is not concerned with the chemistry of the various alternative materials proposed for long-term storage of nuclear wastes. The chemical aspects are discussed from a generic point of view in which the chemistry of important radionuclides is emphasized.

  5. Actinide-Aluminate Speciation in Alkaline Radioactive Waste

    SciTech Connect

    Dr. David L. Clark; Dr. Alexander M. Fedosseev

    2001-12-21

    Investigation of behavior of actinides in alkaline media containing AL(III) showed that no aluminate complexes of actinides in oxidation states (IIII-VIII) were formed in alkaline solutions. At alkaline precipitation IPH (10-14) of actinides in presence of AL(III) formation of aluminate compounds is not observed. However, in precipitates contained actinides (IIV)<(VI), and to a lesser degree actinides (III), some interference of components takes place that is reflected in change of solid phase properties in comparison with pure components or their mechanical mixture. The interference decreases with rise of precipitation PH and at PH 14 is exhibited very feebly. In the case of NP(VII) the individual compound with AL(III) is obtained, however it is not aluminate of neptunium(VII), but neptunate of aluminium(III) similar to neptunates of other metals obtained earlier.

  6. Recent Developments in Nuclear Waste Management in Canada

    SciTech Connect

    King, F.

    2002-02-27

    This paper describes recent developments in the field of nuclear waste management in Canada with a focus on management of nuclear fuel waste. Of particular significance is the April 2001 tabling in the Canadian House of Commons of Bill C-27, An Act respecting the long-term management of nuclear fuel waste. At the time of finalizing this paper (January 15, 2002), Bill C-27 is in Third Reading in the House of Commons and is expected to move to the Senate in February. The Nuclear Fuel Waste Act is expected to come into force later in 2002. This Act requires the three nuclear utilities in Canada owning nuclear fuel waste to form a waste management organization and deposit funds into a segregated fund for nuclear fuel waste long-term management. The waste management organization is then required to perform a study of long-term management approaches for nuclear fuel waste and submit the study to the federal government within three years. The federal government will select an approach for implementation by the waste management organization. The paper discusses the activities that the nuclear fuel waste owners currently have underway to prepare for the formation of the waste management organization. As background, the paper reviews the status of interim storage of nuclear fuel waste in Canada, and describes previous initiatives related to the development of a national strategy for nuclear fuel waste long-term management.

  7. Systems approach to nuclear waste glass development

    SciTech Connect

    Jantzen, C M

    1986-01-01

    Development of a host solid for the immobilization of nuclear waste has focused on various vitreous wasteforms. The systems approach requires that parameters affecting product performance and processing be considered simultaneously. Application of the systems approach indicates that borosilicate glasses are, overall, the most suitable glasses for the immobilization of nuclear waste. Phosphate glasses are highly durable; but the glass melts are highly corrosive and the glasses have poor thermal stability and low solubility for many waste components. High-silica glasses have good chemical durability, thermal stability, and mechanical stability, but the associated high melting temperatures increase volatilization of hazardous species in the waste. Borosilicate glasses are chemically durable and are stable both thermally and mechanically. The borosilicate melts are generally less corrosive than commercial glasses, and the melt temperature miimizes excessive volatility of hazardous species. Optimization of borosilicate waste glass formulations has led to their acceptance as the reference nuclear wasteform in the United States, United Kingdom, Belgium, Germany, France, Sweden, Switzerland, and Japan.

  8. Recovery of fissile materials from nuclear wastes

    DOEpatents

    Forsberg, Charles W.

    1999-01-01

    A process for recovering fissile materials such as uranium, and plutonium, and rare earth elements, from complex waste feed material, and converting the remaining wastes into a waste glass suitable for storage or disposal. The waste feed is mixed with a dissolution glass formed of lead oxide and boron oxide resulting in oxidation, dehalogenation, and dissolution of metal oxides. Carbon is added to remove lead oxide, and a boron oxide fusion melt is produced. The fusion melt is essentially devoid of organic materials and halogens, and is easily and rapidly dissolved in nitric acid. After dissolution, uranium, plutonium and rare earth elements are separated from the acid and recovered by processes such as PUREX or ion exchange. The remaining acid waste stream is vitrified to produce a waste glass suitable for storage or disposal. Potential waste feed materials include plutonium scrap and residue, miscellaneous spent nuclear fuel, and uranium fissile wastes. The initial feed materials may contain mixtures of metals, ceramics, amorphous solids, halides, organic material and other carbon-containing material.

  9. Recovery of fissile materials from nuclear wastes

    SciTech Connect

    Forsberg, C.W.

    1999-10-05

    A process is described for recovering fissile materials such as uranium, and plutonium, and rare earth elements, from complex waste feed material, and converting the remaining wastes into a waste glass suitable for storage or disposal. The waste feed is mixed with a dissolution glass formed of lead oxide and boron oxide resulting in oxidation, dehalogenation, and dissolution of metal oxides. Carbon is added to remove lead oxide, and a boron oxide fusion melt is produced. The fusion melt is essentially devoid of organic materials and halogens, and is easily and rapidly dissolved in nitric acid. After dissolution, uranium, plutonium and rare earth elements are separated from the acid and recovered by processes such as PUREX or ion exchange. The remaining acid waste stream is vitrified to produce a waste glass suitable for storage or disposal. Potential waste feed materials include plutonium scrap and residue, miscellaneous spent nuclear fuel, and uranium fissile wastes. The initial feed materials may contain mixtures of metals, ceramics, amorphous solids, halides, organic material and other carbon-containing material.

  10. Recovery of fissile materials from nuclear wastes

    SciTech Connect

    Forsberg, Charles W.

    1997-12-01

    A process is described for recovering fissile materials such as uranium, and plutonium, and rare earth elements, from complex waste feed material, and converting the remaining wastes into a waste glass suitable for storage or disposal. The waste feed is mixed with a dissolution glass formed of lead oxide and boron oxide resulting in oxidation, dehalogenation, and dissolution of metal oxides. Carbon is added to remove lead oxide, and a boron oxide fusion melt is produced. The fusion melt is essentially devoid of organic materials and halogens, and is easily and rapidly dissolved in nitric acid. After dissolution, uranium, plutonium, and rare earth elements are separated from the acid and recovered by processes such as PUREX or ion exchange. The remaining acid waste stream is vitrified to produce a waste glass suitable for storage or disposal. Potential waste feed materials include plutonium scrap and residue, miscellaneous spent nuclear fuel, and uranium fissile wastes. The initial feed materials may contain mixtures of metals, ceramics, amorphous solids, halides, organic material and other carbon-containing material.

  11. Permanent Disposal of Nuclear Waste in Salt

    NASA Astrophysics Data System (ADS)

    Hansen, F. D.

    2016-12-01

    Salt formations hold promise for eternal removal of nuclear waste from our biosphere. Germany and the United States have ample salt formations for this purpose, ranging from flat-bedded formations to geologically mature dome structures. Both nations are revisiting nuclear waste disposal options, accompanied by extensive collaboration on applied salt repository research, design, and operation. Salt formations provide isolation while geotechnical barriers reestablish impermeability after waste is placed in the geology. Between excavation and closure, physical, mechanical, thermal, chemical, and hydrological processes ensue. Salt response over a range of stress and temperature has been characterized for decades. Research practices employ refined test techniques and controls, which improve parameter assessment for features of the constitutive models. Extraordinary computational capabilities require exacting understanding of laboratory measurements and objective interpretation of modeling results. A repository for heat-generative nuclear waste provides an engineering challenge beyond common experience. Long-term evolution of the underground setting is precluded from direct observation or measurement. Therefore, analogues and modeling predictions are necessary to establish enduring safety functions. A strong case for granular salt reconsolidation and a focused research agenda support salt repository concepts that include safety-by-design. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Author: F. D. Hansen, Sandia National Laboratories

  12. Safety management of nuclear waste in Spain

    SciTech Connect

    Echavarri, L.E. )

    1991-01-01

    For the past two decades, Spain has been consolidating a nuclear program that in the last 3 years has provided between 35 and 40% of the electricity consumed in that country. This program includes nine operating reactor units, eight of them based on US technology and one from Germany, a total of 7,356 MW(electric). There is also a 480-MW(electric) French gas-cooled reactor whose operation recently ceased and which will be decommissioned in the coming years. Spanish industry has participated significantly in this program, and material produced locally has reached 85% of the total. Once the construction program has been completed and operation is proceeding normally, the capacity factor will be {approximately} 80%. It will be very important to complete the nuclear program with the establishment of conditions for safe management and disposal of the nuclear waste generated during the years in which these reactors are in operation and for subsequent decommissioning. To establish the guidelines for the disposal of nuclear waste, the Spanish government approved in october 1987, with a revision in January 1989, the General Plan of Radioactive Wastes proposed by the Ministry of Industry and Energy and prepared by the national company for radioactive waste management, ENRESA.

  13. Nuclear Waste Fund fee adequacy: An assessment

    SciTech Connect

    1990-11-01

    The purpose of this report is to present the Department of Energy`s (the Department) analysis of the adequacy of the 1.00 mill per kilowatt-hour (kWh) fee being paid by the utilities generating nuclear power for the permanent disposal of their spent nuclear fuel (SNF). In accordance with the Nuclear Waste Policy Act (NWPA), the SNF would be disposed of in a geologic repository to be developed by the Department. An annual analysis of the fee`s adequacy is required by the NWPA.

  14. Nuclear waste management. Quarterly progress report, January-March 1980

    SciTech Connect

    Platt, A.M.; Powell, J.A.

    1980-06-01

    Reported are: high-level waste immobilization, alternative waste forms, nuclear waste materials characterization, TRU waste immobilization, TRU waste decontamination, krypton solidification, thermal outgassing, iodine-129 fixation, unsaturated zone transport, well-logging instrumentation development, mobile organic complexes of fission products, waste management system and safety studies, assessment of effectiveness of geologic isolation systems, waste/rock interactions, engineered barriers, criteria for defining waste isolation, and spent fuel and pool component integrity. (DLC)

  15. Nuclear waste issues: a perspectives document

    SciTech Connect

    Cohen, J.J.; Smith, C.F.; Ciminese, F.J.

    1983-02-01

    This report contains the results of systematic survey of perspectives on the question of radioactive waste management. Sources of information for this review include the scientific literature, regulatory and government documents, pro-nuclear and anti-nuclear publications, and news media articles. In examining the sources of information, it has become evident that a major distinction can be made between the optimistic or positive viewpoints, and the pessimistic or negative ones. Consequently, these form the principal categories for presentation of the perspectives on the radioactive waste management problem have been further classified as relating to the following issue areas: the physical aspects of radiation, longevity, radiotoxicity, the quantity of radioactive wastes, and perceptual factors.

  16. Development of alkaline solution separations for potential partitioning of used nuclear fuels

    SciTech Connect

    Jarvinen, Gordon D; Runde, Wolfgang H; Goff, George S

    2009-01-01

    The processing of used nuclear fuel in alkaline solution provides potentially useful new selectivity for separating the actinides from each other and f rom the fission products. Over the ast decade, several research teams around the world have considered dissolution of used fuel in alkaline solution and further partitioning in this medium as an alternative to acid dissolution. The chemistry of the actinides and fission products in alkaline soilltion requires extensive investigation to more carefully evaluate its potential for developing useful separation methods for used nuclear fueI.

  17. Scientific Solutions to Nuclear Waste Environmental Challenges

    SciTech Connect

    Johnson, Bradley R.

    2014-01-30

    The Hidden Cost of Nuclear Weapons The Cold War arms race drove an intense plutonium production program in the U.S. This campaign produced approximately 100 tons of plutonium over 40 years. The epicenter of plutonium production in the United States was the Hanford site, a 586 square mile reservation owned by the Department of Energy and located on the Colombia River in Southeastern Washington. Plutonium synthesis relied on nuclear reactors to convert uranium to plutonium within the reactor fuel rods. After a sufficient amount of conversion occurred, the rods were removed from the reactor and allowed to cool. They were then dissolved in an acid bath and chemically processed to separate and purify plutonium from the rest of the constituents in the used reactor fuel. The acidic waste was then neutralized using sodium hydroxide and the resulting mixture of liquids and precipitates (small insoluble particles) was stored in huge underground waste tanks. The byproducts of the U.S. plutonium production campaign include over 53 million gallons of high-level radioactive waste stored in 177 large underground tanks at Hanford and another 34 million gallons stored at the Savannah River Site in South Carolina. This legacy nuclear waste represents one of the largest environmental clean-up challenges facing the world today. The nuclear waste in the Hanford tanks is a mixture of liquids and precipitates that have settled into sludge. Some of these tanks are now over 60 years old and a small number of them are leaking radioactive waste into the ground and contaminating the environment. The solution to this nuclear waste challenge is to convert the mixture of solids and liquids into a durable material that won't disperse into the environment and create hazards to the biosphere. What makes this difficult is the fact that the radioactive half-lives of some of the radionuclides in the waste are thousands to millions of years long. (The half-life of a radioactive substance is the amount

  18. Can shale safely host US nuclear waste?

    USGS Publications Warehouse

    Neuzil, C.E.

    2013-01-01

    "Even as cleanup efforts after Japan’s Fukushima disaster offer a stark reminder of the spent nuclear fuel (SNF) stored at nuclear plants worldwide, the decision in 2009 to scrap Yucca Mountain as a permanent disposal site has dimmed hope for a repository for SNF and other high-level nuclear waste (HLW) in the United States anytime soon. About 70,000 metric tons of SNF are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers [Blue Ribbon Commission on America’s Nuclear Future, 2012].However, abandoning Yucca Mountain could also result in broadening geologic options for hosting America’s nuclear waste. Shales and other argillaceous formations (mudrocks, clays, and similar clay-rich media) have been absent from the U.S. repository program. In contrast, France, Switzerland, and Belgium are now planning repositories in argillaceous formations after extensive research in underground laboratories on the safety and feasibility of such an approach [Blue Ribbon Commission on America’s Nuclear Future, 2012; Nationale Genossenschaft für die Lagerung radioaktiver Abfälle (NAGRA), 2010; Organisme national des déchets radioactifs et des matières fissiles enrichies, 2011]. Other nations, notably Japan, Canada, and the United Kingdom, are studying argillaceous formations or may consider them in their siting programs [Japan Atomic Energy Agency, 2012; Nuclear Waste Management Organization (NWMO), (2011a); Powell et al., 2010]."

  19. Advanced waste forms from spent nuclear fuel

    SciTech Connect

    Ackerman, J.P.; McPheeters, C.C.

    1995-12-31

    More than one hundred spent nuclear fuel types, having an aggregate mass of more than 5000 metric tons (2700 metric tons of heavy metal), are stored by the United States Department of Energy. This paper proposes a method for converting this wide variety of fuel types into two waste forms for geologic disposal. The method is based on a molten salt electrorefining technique that was developed for conditioning the sodium-bonded, metallic fuel from the Experimental Breeder Reactor-II (EBR-II) for geologic disposal. The electrorefining method produces two stable, optionally actinide-free, high-level waste forms: an alloy formed from stainless steel, zirconium, and noble metal fission products, and a ceramic waste form containing the reactive metal fission products. Electrorefining and its accompanying head-end process are briefly described, and methods for isolating fission products and fabricating waste forms are discussed.

  20. Candidate waste forms for immobilisation of waste chloride salt from pyroprocessing of spent nuclear fuel

    NASA Astrophysics Data System (ADS)

    Vance, E. R.; Davis, J.; Olufson, K.; Chironi, I.; Karatchevtseva, I.; Farnan, I.

    2012-01-01

    Sodalite/glass bodies prepared by hot isostatic pressing (HIPing) at ˜850 °C/100 MPa are candidates for immobilising fission product-bearing waste KCl-LiCl pyroprocessing salts. To study the capacity of sodalite to structurally incorporate such pyroprocessing salts, K, Li, Cs, Sr, Ba and La were individually targeted for substitution in a Na site in sodalite (Na vacancies targeted as charge compensators for alkaline and rare earths) and studied by X-ray diffraction and scanning electron microscopy after sintering in the range of 800-1000 °C. K and Li appeared to enter the sodalite, but Cs, Sr and Ba formed aluminosilicate phases and La formed an oxyapatite phase. However these non-sodalite phases have reasonable resistance to water leaching. Pure chlorapatite gives superior leach resistance to sodalite, and alkalis, alkaline and rare earth ions are generally known to enter chlorapatite, but attempts to incorporate simulated waste salt formulations into HIPed chlorapatite-based preparations or to substitute Cs alone into the structure of Ca-based chlorapatite were not successful on the basis of scanning electron microscopy. The materials exhibited severe water leachability, mainly in regard to Cs release. Attempts to substitute Cs into Ba- and Sr-based chlorapatites also did not look encouraging. Consequently the use of apatite alone to retain fission product-bearing waste pyroprocessing salts from electrolytic nuclear fuel reprocessing is problematical, but chlorapatite glass-ceramics may be feasible, albeit with reduced waste loadings. Spodiosite, Ca 2(PO 4)Cl, does not appear to be suitable for incorporation of Cl-bearing waste containing fission products.

  1. Neutron pulse simulation in nuclear waste for waste characterization

    SciTech Connect

    Toffer, H.; Watson, W.T.; Roetman, V.E.

    1993-12-01

    The numerical simulations discussed in this paper show how analysis with computer-generated illustrations can be used to explain the concepts and advantages of pulsed neutron systems for tank waste evaluations. Furthermore, the analysis-illustration approach lends itself to parametric studies evaluating design features of hardware before it is fabricated. Nuclear material characteristics of hazardous or toxic simulants can be evaluated before preparing them or finding nontoxic or nonhazardous substitutes that will exhibit similar nuclear properties. Pulsed neutron systems hold significant promise for partial characterization of tank waste. The device could operate in a high background gamma radiation field and provide important information on moisture concentrations, fissionable material contents, and material interfaces quickly and at considerably less cost than obtainable from sample analyses.

  2. Strategies for characterizing mixed nuclear wastes: The challenges

    SciTech Connect

    Toste, A.P.

    1993-12-31

    The chemical analysis of nuclear wastes, especially mixed wastes, pose various problems to the analytical chemist. The chemical content may be very complex, particularly when organics are present. This report describes the analysis of two highly radioactive wastes: a neutralized cladding removal waste, and a volume reduction, double-shell slurry waste. The organic content analysis is described.

  3. Assessment of commercially available ion exchange materials for cesium removal from highly alkaline wastes

    SciTech Connect

    Brooks, K.P.; Kim, A.Y.; Kurath, D.E.

    1996-04-01

    Approximately 61 million gallons of nuclear waste generated in plutonium production, radionuclide removal campaigns, and research and development activities is stored on the Department of Energy`s Hanford Site, near Richland, Washington. Although the pretreatment process and disposal requirements are still being defined, most pretreatment scenarios include removal of cesium from the aqueous streams. In many cases, after cesium is removed, the dissolved salt cakes and supernates can be disposed of as LLW. Ion exchange has been a leading candidate for this separation. Ion exchange systems have the advantage of simplicity of equipment and operation and provide many theoretical stages in a small space. The organic ion exchange material Duolite{trademark} CS-100 has been selected as the baseline exchanger for conceptual design of the Initial Pretreatment Module (IPM). Use of CS-100 was chosen because it is considered a conservative, technologically feasible approach. During FY 96, final resin down-selection will occur for IPM Title 1 design. Alternate ion exchange materials for cesium exchange will be considered at that time. The purpose of this report is to conduct a search for commercially available ion exchange materials which could potentially replace CS-100. This report will provide where possible a comparison of these resin in their ability to remove low concentrations of cesium from highly alkaline solutions. Materials which show promise can be studied further, while less encouraging resins can be eliminated from consideration.

  4. Nuclear waste management. Quarterly progress report, October-December 1979

    SciTech Connect

    Platt, A.M.; Powell, J.A.

    1980-04-01

    Progress and activities are reported on the following: high-level waste immobilization, alternative waste forms, nuclear waste materials characterization, TRU waste immobilization programs, TRU waste decontamination, krypton solidification, thermal outgassing, iodine-129 fixation, monitoring of unsaturated zone transport, well-logging instrumentation development, mobile organic complexes of fission products, waste management system and safety studies, assessment of effectiveness of geologic isolation systems, waste/rock interactions technology, spent fuel and fuel pool integrity program, and engineered barriers. (DLC)

  5. Column leaching test to evaluate the use of alkaline industrial wastes to neutralize acid mine tailings

    SciTech Connect

    Doye, I.; Duchesne, J.

    2005-08-01

    Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals that releases highly acidic, sulfate, and metals-rich drainage. In this study, alkaline industrial wastes were mixed with acid mine tailings in order to obtain neutral conditions. A series of column leaching tests were performed to evaluate the behavior of reactive mine tailings amended with alkaline-additions under dynamic conditions. Column tests were conducted of oxidized mine tailings combined with cement kiln dust, red mud bauxite, and mixtures of cement kiln dust with red mud bauxite. The pH results show the addition of 10% of alkaline materials permits the maintenance of near neutral conditions. In the presence of 10% alkaline material, the concentration of toxic metals such as Al, Cu, Fe, Zn are significantly reduced as well as the number of viable cells (Thiobacillus ferrooxidans) compared to control samples.

  6. Review of radiation effects in solid-nuclear-waste forms

    SciTech Connect

    Weber, W.J.

    1981-09-01

    Radiation effects on the stability of high-level nuclear waste (HLW) forms are an important consideration in the development of technology to immobilize high-level radioactive waste because such effects may significantly affect the containment of the radioactive waste. Since the required containment times are long (10/sup 3/ to 10/sup 6/ years), an understanding of the long-term cumulative effects of radiation damage on the waste forms is essential. Radiation damage of nuclear waste forms can result in changes in volume, leach rate, stored energy, structure/microstructure, and mechanical properties. Any one or combination of these changes might significantly affect the long-term stability of the nuclear waste forms. This report defines the general radiation damage problem in nuclear waste forms, describes the simulation techniques currently available for accelerated testing of nuclear waste forms, and reviews the available data on radiation effects in both glass and ceramic (primarily crystalline) waste forms. 76 references.

  7. International nuclear waste management fact book

    SciTech Connect

    Abrahms, C W; Patridge, M D; Widrig, J E

    1995-11-01

    The International Nuclear Waste Management Fact Book has been compiled to provide current data on fuel cycle and waste management facilities, R and D programs, and key personnel in 24 countries, including the US; four multinational agencies; and 20 nuclear societies. This document, which is in its second year of publication supersedes the previously issued International Nuclear Fuel Cycle Fact Book (PNL-3594), which appeared annually for 12 years. The content has been updated to reflect current information. The Fact Book is organized as follows: National summaries--a section for each country that summarizes nuclear policy, describes organizational relationships, and provides addresses and names of key personnel and information on facilities. International agencies--a section for each of the international agencies that has significant fuel cycle involvement and a list of nuclear societies. Glossary--a list of abbreviations/acronyms of organizations, facilities, and technical and other terms. The national summaries, in addition to the data described above, feature a small map for each country and some general information that is presented from the perspective of the Fact Book user in the US.

  8. Melt processed multiphase ceramic waste forms for nuclear waste immobilization

    NASA Astrophysics Data System (ADS)

    Amoroso, Jake; Marra, James C.; Tang, Ming; Lin, Ye; Chen, Fanglin; Su, Dong; Brinkman, Kyle S.

    2014-11-01

    Ceramic waste forms are promising hosts for nuclear waste immobilization as they have the potential for increased durability and waste loading compared with conventional borosilicate glass waste forms. Ceramics are generally processed using hot pressing, spark plasma sintering, and conventional solid-state reaction, however such methods can be prohibitively expensive or impractical at production scales. Recently, melt processing has been investigated as an alternative to solid-state sintering methods. Given that melter technology is currently in use for High Level Waste (HLW) vitrification in several countries, the technology readiness of melt processing appears to be advantageous over sintering methods. This work reports the development of candidate multi-phase ceramic compositions processed from a melt. Cr additions, developed to promote the formation and stability of a Cs containing hollandite phase were successfully incorporated into melt processed multi-phase ceramics. Control of the reduction-oxidation (Redox) conditions suppressed undesirable Cs-Mo containing phases, and additions of Al and Fe reduced the melting temperature.

  9. Nuclear Materials: Reconsidering Wastes and Assets - 13193

    SciTech Connect

    Michalske, T.A.

    2013-07-01

    The nuclear industry, both in the commercial and the government sectors, has generated large quantities of material that span the spectrum of usefulness, from highly valuable ('assets') to worthless ('wastes'). In many cases, the decision parameters are clear. Transuranic waste and high level waste, for example, have no value, and is either in a final disposition path today, or - in the case of high level waste - awaiting a policy decision about final disposition. Other materials, though discardable, have intrinsic scientific or market value that may be hidden by the complexity, hazard, or cost of recovery. An informed decision process should acknowledge the asset value, or lack of value, of the complete inventory of materials, and the structure necessary to implement the range of possible options. It is important that informed decisions are made about the asset value for the variety of nuclear materials available. For example, there is a significant quantity of spent fuel available for recycle (an estimated $4 billion value in the Savannah River Site's (SRS) L area alone); in fact, SRS has already blended down more than 300 metric tons of uranium for commercial reactor use. Over 34 metric tons of surplus plutonium is also on a path to be used as commercial fuel. There are other radiological materials that are routinely handled at the site in large quantities that should be viewed as strategically important and / or commercially viable. In some cases, these materials are irreplaceable domestically, and failure to consider their recovery could jeopardize our technological leadership or national defense. The inventories of nuclear materials at SRS that have been characterized as 'waste' include isotopes of plutonium, uranium, americium, and helium. Although planning has been performed to establish the technical and regulatory bases for their discard and disposal, recovery of these materials is both economically attractive and in the national interest. (authors)

  10. Advanced pyrochemical technologies for minimizing nuclear waste

    SciTech Connect

    Bronson, M.C.; Dodson, K.E.; Riley, D.C.

    1994-12-31

    The US Department of Energy (DOE) is seeking to reduce the size of the current nuclear weapons complex and consequently minimize operating costs. To meet this DOE objective, the national laboratories have been asked to develop advanced technologies that take uranium and plutonium from retired weapons and prepare it for new weapons, long-term storage, and/or final disposition. Current pyrochemical processes generate residue salts and ceramic wastes that require aqueous processing to remove and recover the actinides. However, the aqueous treatment of these residues generates an estimated 100 l of acidic transuranic (TRU) waste per kilogram of plutonium in the residue. Lawrence Livermore National Laboratory (LLNL) is developing pyrochemical techniques to eliminate, minimize, or more efficiently treat these residue streams. This paper presents technologies being developed at LLNL on advanced materials for actinide containment, reactors that minimize residues, and pyrochemical processes that remove actinides from waste salts.

  11. Seal welded cast iron nuclear waste container

    DOEpatents

    Filippi, Arthur M.; Sprecace, Richard P.

    1987-01-01

    This invention identifies methods and articles designed to circumvent metallurgical problems associated with hermetically closing an all cast iron nuclear waste package by welding. It involves welding nickel-carbon alloy inserts which are bonded to the mating plug and main body components of the package. The welding inserts might be bonded in place during casting of the package components. When the waste package closure weld is made, the most severe thermal effects of the process are restricted to the nickel-carbon insert material which is far better able to accommodate them than is cast iron. Use of nickel-carbon weld inserts should eliminate any need for pre-weld and post-weld heat treatments which are a problem to apply to nuclear waste packages. Although the waste package closure weld approach described results in a dissimilar metal combination, the relative surface area of nickel-to-iron, their electrochemical relationship, and the presence of graphite in both materials will act to prevent any galvanic corrosion problem.

  12. MODELING AN ION EXCHANGE PROCESS FOR CESIUM REMOVAL FROM ALKALINE RADIOACTIVE WASTE SOLUTIONS

    SciTech Connect

    Smith, F; Luther Hamm, L; Sebastian Aleman, S; Johnston Michael, J

    2008-08-26

    The performance of spherical Resorcinol-Formaldehyde ion-exchange resin for the removal of cesium from alkaline radioactive waste solutions has been investigated through computer modeling. Cesium adsorption isotherms were obtained by fitting experimental data using a thermodynamic framework. Results show that ion-exchange is an efficient method for cesium removal from highly alkaline radioactive waste solutions. On average, two 1300 liter columns operating in series are able to treat 690,000 liters of waste with an initial cesium concentration of 0.09 mM in 11 days achieving a decontamination factor of over 50,000. The study also tested the sensitivity of ion-exchange column performance to variations in flow rate, temperature and column dimensions. Modeling results can be used to optimize design of the ion exchange system.

  13. Effect of alkaline pretreatment on anaerobic digestion of solid wastes

    SciTech Connect

    Lopez Torres, M. Espinosa Llorens, Ma. del C.

    2008-11-15

    The introduction of the anaerobic digestion for the treatment of the organic fraction of municipal solid waste (OFMSW) is currently of special interest. The main difficulty in the treatment of this waste fraction is its biotransformation, due to the complexity of organic material. Therefore, the first step must be its physical, chemical and biological pretreatment for breaking complex molecules into simple monomers, to increase solubilization of organic material and improve the efficiency of the anaerobic treatment in the second step. This paper describes chemical pretreatment based on lime addition (Ca(OH){sub 2}), in order to enhance chemical oxygen demand (COD) solubilization, followed by anaerobic digestion of the OFMSW. Laboratory-scale experiments were carried out in completely mixed reactors, 1 L capacity. Optimal conditions for COD solubilization in the first step of pretreatment were 62.0 mEq Ca(OH){sub 2}/L for 6.0 h. Under these conditions, 11.5% of the COD was solubilized. The anaerobic digestion efficiency of the OFMSW, with and without pretreatment, was evaluated. The highest methane yield under anaerobic digestion of the pretreated waste was 0.15 m{sup 3} CH{sub 4}/kg volatile solids (VS), 172.0% of the control. Under that condition the soluble COD and VS removal were 93.0% and 94.0%, respectively. The results have shown that chemical pretreatment with lime, followed by anaerobic digestion, provides the best results for stabilizing the OFMSW.

  14. Effects of alkalinity sources on the stability of anaerobic digestion from food waste.

    PubMed

    Chen, Shujun; Zhang, Jishi; Wang, Xikui

    2015-11-01

    This study investigated the effects of some alkalinity sources on the stability of anaerobic digestion (AD) from food waste (FW). Four alkalinity sources, namely lime mud from papermaking (LMP), waste eggshell (WES), CaCO3 and NaHCO3, were applied as buffer materials and their stability effects were evaluated in batch AD. The results showed that LMP and CaCO3 had more remarkable effects than NaHCO3 and WES on FW stabilization. The methane yields were 120.2, 197.0, 156.2, 251.0 and 194.8 ml g(-1) VS for the control and synergistic digestions of CaCO3, NaHCO3, LMP and WES added into FW, respectively. The corresponding final alkalinity reached 5906, 7307, 9504, 7820 and 6782 mg l(-1), while the final acidities were determined to be 501, 200, 50, 350 and 250 mg l(-1), respectively. This indicated that the synergism between alkalinity and inorganic micronutrients from different alkalinity sources played an important role in the process stability of AD from FW.

  15. Contributions of basic nuclear physics to the nuclear waste management

    NASA Astrophysics Data System (ADS)

    Flocard, Hubert

    2002-04-01

    Nuclear fission is presently a contested method of electricity production. The issue of nuclear waste management stands out among the reasons why. On the other hand, the nuclear industry has demonstrated its capacity to reliably generate cheap electricity while producing negligible amounts of greenhouse gases. These assets explain why this form of energy is still considered among the options for the long term production of electricity at least in developed countries. However, in order to tackle the still not adequately answered question of the waste, new schemes may have to be considered. Among those which have been advanced recently, the less polluting cycles such as those based on Thorium rather than Uranium and/or the transmutation of the minor actinides and some long lived fission products of the present cycle have been actively investigated. In both cases, it turns that the basic knowledge underlying these methods is either missing or incomplete. This situation opens a window of opportunity for useful contributions from basic nuclear physicists. This article describes some of them and presents the ongoing activities as well as some of the projects put forth for the short or medium term. .

  16. Nuclear waste; Can we contain it

    SciTech Connect

    King, F.; Ikeda, B.M.; Shoesmith, D.W.

    1992-04-01

    This paper reports that the safe disposal of nuclear waste requires that the waste be isolated from the environment until radioactive decay has reduced its toxicity to innocuous levels. The disposal of such wastes deep in stable geological formations has been extensively researched since the late 1970s and is now the preferred option internationally. In all of the proposed disposal concepts, the natural barrier of the geological formation is supplemented by a series of engineered barriers each of which retards the transport of radionuclides to the environment. The geological formations being considered usually fall into one of three general categories: crystalline rock (Canada, Sweden, Switzerland, United Kingdom, United States); salt deposits (United States, Germany); and sedimentary deposits, such as clay or seabed sediments (Belgium, United Kingdom, United States), illustrates the Canadian disposal concept based on disposal in igneous rock in the Canadian Shield. The waste will consist of either used fuel bundles or immobilized reprocessed material. In the multibarrier approach the principal engineered component, and the only absolute barrier, is a metallic container enclosing the waste. The required period of containment will influence the choice of material and the thickness of the container.

  17. Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts

    SciTech Connect

    Levitskaia, Tatiana G.; Lumetta, Gregg J.; Moyer, Bruce A.; Bonnesen, Peter V.

    2006-06-01

    The purpose of this research involving collaboration between Oak Ridge National Laboratory (ORNL) and Pacific Northwest National Laboratory (PNNL) is to explore new approaches to the separation of sodium hydroxide, sodium nitrate, and other sodium salts from high-level alkaline tank waste. The principal potential benefit is a major reduction in disposed waste volume, obviating the building of expensive new waste tanks and reducing the costs of low-activity waste immobilization. Principles of ion recognition are being researched toward discovery of liquid extraction systems that selectively separate sodium hydroxide and sodium nitrate from other waste components. The successful concept of pseudohydroxide extraction using fluorinated alcohols and phenols is being developed at ORNL and PNNL toward a greater understanding of the controlling equilibria, role of solvation, and of synergistic effects involving crown ethers. Studies at PNNL are directed toward new solvent formulation for the practical sodium pseudohydroxide extraction systems.

  18. Nuclear Waste Programs semiannual progress report, April--September 1992

    SciTech Connect

    Bates, J.K.; Bradley, C.R.; Buck, E.C.

    1994-05-01

    This document reports on the work done by the Nuclear Waste Programs of the Chemical Technology Division (CMT), Argonne National Laboratory, in the period April--September 1992. In these programs, studies are underway on the performance of waste glass and spent fuel in projected nuclear repository conditions to provide input to the licensing of the nation`s high-level waste repositories.

  19. Nitrogenous Waste Handling by Larval Zebrafish Danio rerio in Alkaline Water.

    PubMed

    Kumai, Yusuke; Harris, Jessica; Al-Rewashdy, Hasanen; Kwong, Raymond W M; Perry, Steve F

    2015-01-01

    Although adult fish excrete their nitrogenous waste primarily as ammonia, larval fish may excrete a higher proportion as urea, an evolutionary strategy that lessens nitrogenous waste toxicity during early development. Previous studies firmly established that ammonia excretion is inhibited in adult fish acutely exposed to alkaline water. This study was designed to test the hypothesis that total nitrogen excretion is maintained in larval zebrafish raised in alkaline water (pH ∼ 10.0) as a result of compensatory adjustments to urea and/or ammonia transport pathways. Raising zebrafish in alkaline water from 0 to 4 d postfertilization (dpf) reduced ammonia excretion at 4 dpf, whereas urea excretion was elevated by 141%. The increase in urea excretion at 4 dpf served to maintain total nitrogen excretion constant, despite the persistent inhibition of ammonia excretion. Whole body ammonia and urea contents were not significantly altered by exposure to alkaline water. Protein and mRNA expression of Rhcg1, an apically expressed ammonia-conducting channel, were significantly elevated after 4-d exposure to alkaline water, whereas the mRNA expression of Rhag, Rhbg, and urea transporter were unaffected. The acute exposure to alkaline water of 4-dpf larvae reared in control water caused a rapid inhibition of ammonia excretion that had partially recovered within 6 h of continued exposure. The partial recovery of ammonia excretion despite continued exposure to alkaline water suggested an increased ammonia excretion capacity. In agreement with an increased capacity to excrete ammonia, the transfer of larvae back to the control (normal pH) water was accompanied by increased rates of ammonia excretion. Urea excretion was not stimulated during 6-h exposure to alkaline water. Following both chronic and acute exposure to alkaline water, the rate of uptake of methylamine (an ammonia analog) was significantly elevated, consistent with increased protein expression of the apical ammonia

  20. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Advisory Committee on Nuclear Waste. 1.18 Section 1.18 Energy NUCLEAR REGULATORY COMMISSION STATEMENT OF ORGANIZATION AND GENERAL INFORMATION Headquarters Panels, Boards, and Committees § 1.18 Advisory Committee on Nuclear Waste. The Advisory Committee...

  1. Alternative Approaches to Recycling Nuclear Wastes

    NASA Astrophysics Data System (ADS)

    Hannum, William H.

    2007-04-01

    Nuclear power exists, and as the demand for non-fossil electricity generation increases, many more nuclear plants are being planned and built. The result is growing inventories of spent nuclear fuel containing plutonium that -- in principle, at least -- can be used to make nuclear explosives. There are countries and organizations that are believed to want nuclear weapons, posing a knotty proliferation problem that calls for realistic control of nuclear materials. Phasing out nuclear power and sequestering all dangerous materials in guarded storage or in geological formations would not be a realistic approach. Plutonium from commercial spent fuel is very hard to make into a weapon. However, a rogue nation could operate a power plant so as to produce plutonium with weapons-quality isotopics, and then chemically purify it. IAEA safeguards are designed to discourage this, but the only enforcement is referral to the United Nations General Assembly. The traditional reprocessing method, PUREX, produces plutonium that has the chemical purity needed for weapons. However, there are alternative approaches that produce only highly radioactive blends of fissionable materials and fission products. Recycle offers a market for spent nuclear fuel, promoting more rigorous accounting of these materials. Unlike PUREX, the new technologies permit the recycle and consumption of essentially all of the high-hazard transuranics, and will reduce the required isolation time for the waste to less than 500 years. Facilities for recovering recyclable materials from LWR spent fuel will be large and expensive. Only a very few such plants will be needed, leading to appropriate concentration of safeguards measures. Plants for recycling the spent fuel from fast burner reactors can be collocated with the power plants and share the safeguards.

  2. Waste Stream Analyses for Nuclear Fuel Cycles

    SciTech Connect

    N. R. Soelberg

    2010-08-01

    A high-level study was performed in Fiscal Year 2009 for the U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) Advanced Fuel Cycle Initiative (AFCI) to provide information for a range of nuclear fuel cycle options (Wigeland 2009). At that time, some fuel cycle options could not be adequately evaluated since they were not well defined and lacked sufficient information. As a result, five families of these fuel cycle options are being studied during Fiscal Year 2010 by the Systems Analysis Campaign for the DOE NE Fuel Cycle Research and Development (FCRD) program. The quality and completeness of data available to date for the fuel cycle options is insufficient to perform quantitative radioactive waste analyses using recommended metrics. This study has been limited thus far to qualitative analyses of waste streams from the candidate fuel cycle options, because quantitative data for wastes from the front end, fuel fabrication, reactor core structure, and used fuel for these options is generally not yet available.

  3. A STUDY OF CORROSION AND STRESS CORROSION CRACKING OF CARBON STEEL NUCLEAR WASTE STORAGE TANKS

    SciTech Connect

    BOOMER, K.D.

    2007-08-21

    The Hanford reservation Tank Farms in Washington State has 177 underground storage tanks that contain approximately 50 million gallons of liquid legacy radioactive waste from cold war plutonium production. These tanks will continue to store waste until it is treated and disposed. These nuclear wastes were converted to highly alkaline pH wastes to protect the carbon steel storage tanks from corrosion. However, the carbon steel is still susceptible to localized corrosion and stress corrosion cracking. The waste chemistry varies from tank to tank, and contains various combinations of hydroxide, nitrate, nitrite, chloride, carbonate, aluminate and other species. The effect of each of these species and any synergistic effects on localized corrosion and stress corrosion cracking of carbon steel have been investigated with electrochemical polarization, slow strain rate, and crack growth rate testing. The effect of solution chemistry, pH, temperature and applied potential are all considered and their role in the corrosion behavior will be discussed.

  4. Public reactions to nuclear waste: Citizens' views of repository siting

    SciTech Connect

    Rosa, E.A.

    1993-01-01

    This book presents revised and updated papers from a panel of social scientists, at the 1989 AAAS meetings, that examined the public's reactions to nuclear waste disposal and the repository siting process. The papers report the results of original empirical research on citizens' views of nuclear waste repository siting. Topics covered include the following: content analysis of public testimony; sources of public concern about nuclear waste disposal in Texas agricultural communities; local attitudes toward high-level waste repository at Hanford; perceived risk and attitudes toward nuclear wastes; attitudes of Nevada urban residents toward a nuclear waste repository; attitudes of rural community residents toward a nuclear waste respository. An introductory chapter provides background and context, and a concluding chapter summarizes the implications of the reports. Two additional chapters cover important features of high-level waste disposal: long term trends in public attitudes toward nuclear energy and nuclear waste policy and assessment of the effects on the Los Vegas convention business if a high-level nuclear waste depository were sited in Nevada.

  5. Alkaline subcritical water gasification of dairy industry waste (Whey).

    PubMed

    Muangrat, Rattana; Onwudili, Jude A; Williams, Paul T

    2011-05-01

    The near-critical water gasification of dairy industry waste in the form of Whey, a product composed of mixtures of carbohydrates (mainly lactose) and amino acids such as glycine and glutamic acid, has been studied. The gasification process involved partial oxidation with hydrogen peroxide in the presence of NaOH. The reactions were studied over the temperature range from 300°C to 390°C, corresponding pressures of 9.5-24.5 MPa and reaction times from 0 min to 120 min. Hydrogen production was affected by the presence of NaOH, the concentration of H(2)O(2), temperature, reaction time and feed concentration. Up to 40% of the theoretical hydrogen gas production was achieved at 390°C. Over 80% of the Whey nitrogen content was found as ammonia, mainly in the liquid effluent.

  6. Congress Examines Nuclear Waste Disposal Recommendations

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-02-01

    During an 8 February U.S. congressional hearing to examine how to move forward on dealing with spent nuclear fuel and to review other recommendations of the recently released final report of the White House-appointed Blue Ribbon Commission on America's Nuclear Future (BRC), Yucca Mountain was the 65,000-ton gorilla in the room. BRC's charge was to conduct a comprehensive review of policies to manage the back end of the nuclear fuel cycle and recommend a new strategy for dealing with the 65,000 tons of spent nuclear fuel currently stored at 75 sites around the country and the 2000 tons of new spent fuel being produced each year. However, BRC specifically did not evaluate Yucca Mountain. A 26 January letter from BRC to U.S. secretary of energy Steven Chu states, "You directed that the Commission was not to serve as a siting body. Accordingly, we have not evaluated Yucca Mountain or any other location as a potential site for the storage of spent nuclear fuel or disposal of high-level waste nor have we taken a position on the administration's request to withdraw the Yucca Mountain license application."

  7. Effect of alkalinity on the performance of a simulated landfill bioreactor digesting organic solid wastes.

    PubMed

    Ağdağ, Osman Nuri; Sponza, Delia Teresa

    2005-05-01

    This study investigated the effects of alkalinity on the anaerobic treatment of the organic solid wastes collected from the kitchen of Engineering Faculty in Dokuz Eylul University, Izmir, Turkey and the leachate characteristics treated in three simulated landfill anaerobic bioreactors. All of the reactors were operated with leachate recirculation. One reactor was operated without alkalinity addition. The second reactor was operated by the addition of 3 g l-1 d-1 of NaHCO3 alkalinity to the leachate and the third reactor was operated by the addition of 6 g l-1 d-1 NaHCO3 alkalinity to the leachate. After 65 d of anaerobic incubation, it was observed that the chemical oxygen demand (COD), volatile fatty acids (VFA) concentrations, and biochemical oxygen demand to chemical oxygen demand (BOD5/COD) ratios in the leachate samples produced from the alkalinity added reactors were lower than the control reactor while the pH values were higher than the control reactor. The COD values were measured as 18900, 3800 and 2900 mg l-1 while the VFA concentrations were 6900, 1400 and 1290 mg l-1, respectively, in the leachate samples of the control, and reactors containing 3 g l-1 NaHCO3 and 6 g l-1 NaHCO3 after 65 d of anaerobic incubation. The total nitrogen (TN), total phosphorus (TP) and ammonium nitrogen (NH4-N) concentrations in organic solid waste (OSW) significantly reduced in the reactor containing 6 g l-1 NaHCO3 by d 65. The values of pH were 6.54, 7.19 and 7.31, after 65 d of anaerobic incubation, respectively, in the aforementioned reactors results in neutral environmental conditions in alkalinity added reactors. Methane percentage of the control, reactors containing 3 g l-1 NaHCO3 and 6 g l-1 NaHCO3 were 37%, 64% and 65%, respectively, after 65 d of incubation. BOD5/COD ratios of 0.27 and 0.25 were achieved in the 3 and 6 g l-1 NaHCO3 containing reactors, indicating a better OSW stabilization. Alkalinity addition reduced the waste quantity, the organic content of the

  8. Extraction of cesium and strontium from nuclear waste

    DOEpatents

    Davis, M.W. Jr.; Bowers, C.B. Jr.

    1988-06-07

    Cesium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4[prime](5) [1-hydroxy-2-ethylhexyl]benzo 18-crown-6 compound and a cation exchanger in a matrix solution. Strontium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4[prime](5[prime]) [1-hydroxyheptyl]cyclohexo 18-crown-6 compound, and a cation exchanger in a matrix solution. 3 figs.

  9. Extraction of cesium and strontium from nuclear waste

    DOEpatents

    Davis, Jr., Milton W.; Bowers, Jr., Charles B.

    1988-01-01

    Cesium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5) [1-hydroxy-2-ethylhexyl]benzo 18-crown-6 compound and a cation exchanger in a matrix solution. Strontium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5') [1-hydroxyheptyl]cyclohexo 18-crown-6 compound, and a cation exchanger in a matrix solution.

  10. Nevada may lose nuclear waste funds

    SciTech Connect

    Marshall, E.

    1988-06-24

    The people of Nevada are concerned that a cut in DOE funding for a nuclear waste repository at Yucca Mountain, Nevada will result in cuts in the state monitoring program, e.g. dropping a seismic monitoring network and a sophisticated drilling program. Economic and social impact studies will be curtailed. Even though a provision to curtail local research forbids duplication of DOE`s work and would limit the ability of Nevada to go out and collect its own data, Nevada State University at Las Vegas would receive a nice plum, a top-of-the-line supercomputer known as the ETA-10 costing almost $30 million financed by DOE.

  11. Remediation of Groundwater Contaminated by Nuclear Waste

    NASA Astrophysics Data System (ADS)

    Parker, Jack; Palumbo, Anthony

    2008-07-01

    A Workshop on Accelerating Development of Practical Field-Scale Bioremediation Models; An Online Meeting, 23 January to 20 February 2008; A Web-based workshop sponsored by the U.S. Department of Energy Environmental Remediation Sciences Program (DOE/ERSP) was organized in early 2008 to assess the state of the science and knowledge gaps associated with the use of computer models to facilitate remediation of groundwater contaminated by wastes from Cold War era nuclear weapons development and production. Microbially mediated biological reactions offer a potentially efficient means to treat these sites, but considerable uncertainty exists in the coupled biological, chemical, and physical processes and their mathematical representation.

  12. Ancient metallurgy and nuclear waste containment

    SciTech Connect

    Goodway, M.

    1993-12-31

    Archaeological artifacts of glass, ceramic, and metal provide examples of long term durability and as such have been surveyed by the nuclear agencies of several countries as a possible guide to choices of materials for the containment of nuclear waste. In the case of metals evaluation is difficult because of the loss of many artifacts to recycling and corrosion processes, as well as by uncertainty as to the environmental history under which the remainder survived. More recently the study of ancient metallurgy has expanded to included other materials associated with metals processing. It is suggested that an impermeable ceramic composite used in ancient metals processing installations should be reproduced and tested for its resistance to radiation damage. This material was synthesized more than two millennia ago and has a proven record of durability. These installations have had no maintenance but are intact, some still holding water.

  13. Informing future societies about nuclear waste repositories

    SciTech Connect

    Jensen, M.

    1994-04-01

    In 1990 a working group of the NKS (the Nordic nuclear safety program) was formed and give the task of established a basis for a common Nordic view of the need for information conservation for nuclear waste repositories. The Group investigated what tipy of information should be conserved; in what form the information should be kept; the quality of the information; and the problems of future retrieval of information, including retrieval after very long periods of time. Topics covered include the following: scientific aspects including social context of scientific solutions; information management; systems for conservation and retrieval of information including the problems of prediction; archives, markers, archives vs. markers, and continuing processes in society; Archive media including paper documents, microfilm, digital media, media lifetimes; and finally conclusions and recommendations.

  14. The cost of alkaline solutions in ambulatory hemodialysis: an analysis about wasteful from the processes control.

    PubMed

    de Moraes Junior, Celso Souza; de Mendonça, Ricardo Rodrigues Silveira; Hatem, Raquel Oliveira Rocha de Freitas; Souza, André Luiz Sampaio; Chaves, Adriana Rodrigues; Bastos, Marcus Gomes; Colugnati, Fernando Antônio Basile

    2014-01-01

    There are few studies about costs of inputs used in hemodialysis and among these expenditures, the compounds that make up the dialysate are one of the values considered as representative of this therapy. However, there aren't costs studies that guiding solutions. The objective of this article is discuss whether there is wasteful of alkaline solutions in ambulatory hemodialysis and hence the possibility of reduction in cost from the standardization process simulation of establishment of dialysate flow in periods between shifts in hemodialysis outpatients. Starting from an observational analytic, a simulation was performed twenty case scenarios, which ten cases established by standardizing processes control on the dialysate flow in recession. The combination of data was performed using as a basis the prices of three suppliers of alkali liquid or powder. It was observed among the scenarios with standardized processes, ranging between 7.7% and 33.3% savings in the alkaline solution cost (powder or liquid), by reducing waste. It is possible to restrain the wasteful use of alkaline solutions, both powder and liquid. Consequently, its cost from the patterning on reducing the flow of dialysate during the intervals between shifts observed in the outpatient hemodialysis. However, these results are conditional upon the commitment of health professionals, mainly to supervision exercise and control of activities in quality function deployment.

  15. Idaho Nuclear Technology and Engineering Center Low-Activity Waste Process Technology Program FY-98 Status Report

    SciTech Connect

    Herbst, A.K.; McCray, J.A.; Rogers, A.Z.; Simmons, R.F.; Palethrope, S.J.

    1999-03-01

    The Low-Activity Waste Process Technology Program at the Idaho Nuclear Technology and Engineering Center (INTEC) anticipates that large volumes of low-level/low-activity wastes will need to be grouted prior to near-surface disposal. During fiscal year 1998, three grout formulations were studied for low-activity wastes derived from INTEC liquid sodium-bearing waste. Compressive strength and leach results are presented for phosphate bonding cement, acidic grout, and alkaline grout formulations. In an additional study, grout formulations are recommended for stabilization of the INTEC underground storage tank residual heels.

  16. Idaho Nuclear Technology and Engineering Center Low-Activity Waste Process Technology Program, FY-98 Status Report

    SciTech Connect

    Herbst, A.K.; Rogers, A.Z.; McCray, J.A.; Simmons, R.F.; Palethorpe, S.J.

    1999-03-01

    The Low-Activity Waste Process Technology Program at the Idaho Nuclear Technology and Engineering Center (INTEC) anticipates that large volumes of low-level/low-activity wastes will need to be grouted prior to near-surface disposal. During fiscal year 1998, three grout formulations were studied for low-activity wastes derived from INTEC liquid sodium-bearing waste. Compressive strength and leach results are presented for phosphate bonding cement, acidic grout, and alkaline grout formulations. In an additional study, grout formulations are recommended for stabilization of the INTEC underground storage tank residual heels.

  17. Idaho Nuclear Technology and Engineering Center Low-Activity Waste Process Technology Program FY-98 Status Report

    SciTech Connect

    Herbst, Alan Keith; Mc Cray, John Alan; Rogers, Adam Zachary; Simmons, R. F.; Palethorpe, S. J.

    1999-03-01

    The Low-Activity Waste Process Technology Program at the Idaho Nuclear Technology and Engineering Center (INTEC) anticipates that large volumes of low-level/low-activity wastes will need to be grouted prior to near-surface disposal. During fiscal year 1998, three grout formulations were studied for low-activity wastes derived from INTEC liquid sodium-bearing waste. Compressive strength and leach results are presented for phosphate bonding cement, acidic grout, and alkaline grout formulations. In an additional study, grout formulations are recommended for stabilization of the INTEC underground storage tank residual heels.

  18. Effect of alkaline treatment on the characterization of zalacca midrib wastes fibers

    NASA Astrophysics Data System (ADS)

    Raharjo, Wahyu Purwo; Soenoko, Rudy; Purnowidodo, Anindito; Choiron, Mochammad Agus; Triyono

    2016-03-01

    Nowadays, the need for new materials is urgent due to the scarcity of conventional materials and energy resources. The environmental issue requires materials which are biodegradable. There are many composites, arranged from synthetic fibers and matrix, which cannot be recyclable after their lifetime. In this research, the utilization potency of zalacca midrib wastes for their fibers as composite reinforcement were investigated, especially after the alkaline treatment to improve their characteristics. The influence of alkaline treatment on the density, functional groups of the fiber surface, thermal stability and crystallinity were measured and/or analyzed by linear-density-and-diameter-calculation, FTIR, TGA-DTA and XRD, respectively. The result showed that the zalacca midrib fibers had lower density than synthetic fibers and several natural fibers. Analysis of FTIR spectra indicated that the alkaline treatment of NaOH slightly raised their density because it removed several functional groups which attributed to the hemicellulose and lignin. TGA-DTA analysis indicated that zalacca fibers had good thermal stability until temperature of 220°C and it was improved by alkaline treatment. XRD analysis showed that the crystallinity of zalacca fibers was higher than several natural fibers like rice straw, sorghum stem and wheat straw fibers. Their crystallinity index was higher than wheat straw fiber. The alkaline treatment increases the crystallinity and crystallinity index rather than untreated fibers.

  19. Corrosion Behavior of Nuclear Waste Storage Canister Materials

    NASA Astrophysics Data System (ADS)

    Grant, John

    The nature of interaction of mild steel nuclear waste storage containers with technetium ions is not fully known. Technetium is formed during nuclear processing and some of this technetium has leaked at the Hanford nuclear waste storage site in Washington State. It is often found as highly oxidized pertechnetate (TeO4-) anions at these storage sites which also happen to be highly alkaline and contain a significant amount of nitrate. Theoretically, pertechnetate anions can act as electron acceptors and interact with the mild steel containers and accelerate the oxidation (corrosion) of steel. It is of interest to identify if pertechnetate anions pose a corrosion hazard to the mild steel nuclear waste storage tanks, under the conditions of the storage sites, as that can accelerate the degradation of the tanks and lead to further contamination. In this thesis, the interaction of two relevant container materials, namely, steel alloys A285 and A537 with a technetium surrogate, rhenium was studied. Perrhenate was used as an analog for pertechnetate. As all isotopes of technetium are radioactive, rhenium was chosen as the experimental surrogate due to its chemical similarity to technetium. Electrochemical behavior was evaluated using potentiodynamic polarization tests, and the surface morphology was studied using optical microscopy and scanning electron microscopy. Potentiodynamic polarization tests were conducted in 1.0M NaNO3 + 0.1M NaOH and 1.0M NaNO3 + 0.1M NaOH + 0.02M NaReO4. Tests were performed at three different temperatures, namely, (i) room temperature, (ii) 50°C and (iii) 80°C to study the effect of higher temperatures found in the storage sites. Corrosion current, corrosion potential, anodic and cathodic Tafel slopes, polarization resistance and corrosion rates were obtained from electrochemical testing and evaluated. Increasing temperatures was found to lead to increasing corrosion rates for all samples. The data also revealed increased corrosion from

  20. Nuclear waste: Quarterly report on DOE`s nuclear waste program as of March 31, 1988

    SciTech Connect

    1988-12-31

    As part of the Department of Energy`s implementation of the Nuclear Waste Policy Act of 1982, DOE is required to investigate a site at Yucca Mountain, Nevada and, if it determines that the site is suitable, recommend to the President its selection for a nuclear waste repository. The Nuclear Regulatory Commission, in considering development of the plan, issued five objections, one of which is DOE`s failure to recognize the range of alternative conceptual models of the Yucca Mountain site that can be supported by the limited existing technical data. At the end of the quarter DOE directed its project offices in Washington and Texas to begin an orderly phase-out of all site-specific repository activities. Costs for this phase-out are $53 million of the Deaf Smith site and $85 million for the Hanford site.

  1. Liquid centrifugation for nuclear waste partitioning

    SciTech Connect

    Bowman, C.D.

    1992-03-11

    The performance of liquid centrifugation for nuclear waste partitioning is examined for the Accelerator Transmutation of Waste Program currently under study at the Los Alamos National Laboratory. Centrifugation might have application for the separation of the LiF-BeF{sub 2} salt from heavier radioactive materials fission product and actinides in the separation of fission product from actinides, in the isotope separation of fission-product cesium before transmutation of the {sup 137}Cs and {sup 135}Cs, and in the removal of spallation product from the liquid lead target. It is found that useful chemical separations should be possible using existing materials for the centrifuge construction for all four cases with the actinide fraction in fission product perhaps as low as 1 part in 10{sup 7} and the fraction of {sup 137}CS in {sup 133}Cs being as low as a few parts in 10{sup 5}. A centrifuge cascade has the advantage that it can be assembled and operated as a completely closed system without a waste stream except that associated with maintenance or replacement of centrifuge components.

  2. Extrapolation of nuclear waste glass aging

    SciTech Connect

    Byers, C.D.; Ewing, R.C.; Jercinovic, M.J.; Keil, K.

    1984-01-01

    Increased confidence is provided to the extrapolation of long-term waste form behavior by comparing the alteration of experimentally aged natural basaltic glass to the condition of the same glass as it has been geologically aged. The similarity between the laboratory and geologic alterations indicates that important aging variables have been identified and incorporated into the laboratory experiments. This provides credibility to the long-term predictions made for waste form borosilicate glasses using similar experimental procedures. In addition, these experiments have demonstrated that the aging processes for natural basaltic glass are relevant to the alteration of nuclear waste glasses, as both appear to react via similar processes. The alteration of a synthetic basaltic glass was measured in MCC-1 tests done at 90/sup 0/C, a SA/V of 0.1 cm/sup -1/ and time periods up to 182 days. Tests were also done using (1) MCC-2 procedures at 190/sup 0/C, a SA/V of 0.1 cm/sup -1/ and time periods up to 91 days and (2) hydration tests in saturated water vapor at 240/sup 0/C, a SA/V of approx. 10/sup 6/ cm/sup -1/, and time periods up to 63 days. These results are compared to alteration observed in natural basaltic glasses of great age. 6 references, 6 figures, 1 table.

  3. Survival of prokaryotes in a polluted waste dump during remediation by alkaline hydrolysis.

    PubMed

    Nielsen, Marie Bank; Kjeldsen, Kasper Urup; Lever, Mark Alexander; Ingvorsen, Kjeld

    2014-04-01

    A combination of culture-dependent and culture-independent techniques was used to characterize bacterial and archaeal communities in a highly polluted waste dump and to assess the effect of remediation by alkaline hydrolysis on these communities. This waste dump (Breakwater 42), located in Denmark, contains approximately 100 different toxic compounds including large amounts of organophosphorous pesticides such as parathions. The alkaline hydrolysis (12 months at pH >12) decimated bacterial and archaeal abundances, as estimated by 16S rRNA gene-based qPCR, from 2.1 × 10(4) and 2.9 × 10(3) gene copies per gram wet soil respectively to below the detection limit of the qPCR assay. Clone libraries constructed from PCR-amplified 16S rRNA gene fragments showed a significant reduction in bacterial diversity as a result of the alkaline hydrolysis, with preferential survival of Betaproteobacteria, which increased in relative abundance from 0 to 48 %. Many of the bacterial clone sequences and the 27 isolates were related to known xenobiotic degraders. An archaeal clone library from a non-hydrolyzed sample showed the presence of three main clusters, two representing methanogens and one representing marine aerobic ammonia oxidizers. Isolation of alkalitolerant bacterial pure cultures from the hydrolyzed soil confirmed that although alkaline hydrolysis severely reduces microbial community diversity and size certain bacteria survive a prolonged alkaline hydrolysis process. Some of the isolates from the hydrolyzed soil were capable of growing at high pH (pH 10.0) in synthetic media indicating that they could become active in in situ biodegradation upon hydrolysis.

  4. Alkaline bioleaching of municipal solid waste incineration fly ash by autochthonous extremophiles.

    PubMed

    Ramanathan, Thulasya; Ting, Yen-Peng

    2016-10-01

    The increasing demand for energy and the generation of solid waste have caused an alarming rise in fly ash production globally. Since heavy metals continue to be in demand for the production of materials, resource recovery from the recycling of these wastes has the potential to delay the depletion of natural ores. The use of microorganisms for the leaching of metals, in a process called bioleaching, is an eco-friendly and economical way to treat the metal-laden wastes. Bioleaching of fly ash is challenging due largely to the alkaline nature and toxic levels of heavy metals which are detrimental to microbial growth and bioleaching activity. The present work reports the isolation of indigenous bacteria from a local fly ash landfill site and their bioleaching performance. 38 autochthonous strains of bacteria were isolated from eight samples collected and plated on five different media. 18 of the isolates showed bioleaching potential, with significant alkaline pH or fly ash tolerance. Genetic characterization of the strains revealed a dominance of Firmicutes, with Alkalibacterium sp. TRTYP6 showing highest fly ash tolerance of up to 20% w/v fly ash, and growth over a pH range 8-12.5. The organism selectively recovered about 52% Cu from the waste. To the best of our knowledge, this is the first time a study on bioleaching with extreme alkaliphiles is reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Inactivation of Geobacillus stearothermophilus spores by alkaline hydrolysis applied to medical waste treatment.

    PubMed

    Pinho, Sílvia C; Nunes, Olga C; Lobo-da-Cunha, Alexandre; Almeida, Manuel F

    2015-09-15

    Although alkaline hydrolysis treatment emerges as an alternative disinfection/sterilization method for medical waste, information on its effects on the inactivation of biological indicators is scarce. The effects of alkaline treatment on the resistance of Geobacillus stearothermophilus spores were investigated and the influence of temperature (80 °C, 100 °C and 110 °C) and NaOH concentration was evaluated. In addition, spore inactivation in the presence of animal tissues and discarded medical components, used as surrogate of medical waste, was also assessed. The effectiveness of the alkaline treatment was carried out by determination of survival curves and D-values. No significant differences were seen in D-values obtained at 80 °C and 100 °C for NaOH concentrations of 0.5 M and 0.75 M. The D-values obtained at 110 °C (2.3-0.5 min) were approximately 3 times lower than those at 100 °C (8.8-1.6 min). Independent of the presence of animal tissues and discarded medical components, 6 log10 reduction times varied between 66 and 5 min at 100 °C-0.1 M NaOH and 110 °C-1 M NaOH, respectively. The alkaline treatment may be used in future as a disinfection or sterilization alternative method for contaminated waste.

  6. Melt processed crystalline ceramic waste forms for advanced nuclear fuel cycles: CRP T21027 1813: Processing technologies for high level waste, formulation of matrices and characterization of waste forms, Task 17208: Final report

    SciTech Connect

    Amoroso, J. W.; Marra, J. C.

    2015-08-26

    A multi-phase ceramic waste form is being developed at the Savannah River National Laboratory (SRNL) for treatment of secondary waste streams generated by reprocessing commercial spent nuclear. The envisioned waste stream contains a mixture of transition, alkali, alkaline earth, and lanthanide metals. Ceramic waste forms are tailored (engineered) to incorporate waste components as part of their crystal structure based on knowledge from naturally found minerals containing radioactive and non-radioactive species similar to the radionuclides of concern in wastes from fuel reprocessing. The ability to tailor ceramics to mimic naturally occurring crystals substantiates the long term stability of such crystals (ceramics) over geologic timescales of interest for nuclear waste immobilization [1]. A durable multi-phase ceramic waste form tailored to incorporate all the waste components has the potential to broaden the available disposal options and thus minimize the storage and disposal costs associated with aqueous reprocessing. This report summarizes results from three years of work on the IAEA Coordinated Research Project on “Processing technologies for high level waste, formulation of matrices and characterization of waste forms” (T21027), and specific task “Melt Processed Crystalline Ceramic Waste Forms for Advanced Nuclear Fuel Cycles” (17208).

  7. Melt processed crystalline ceramic waste forms for advanced nuclear fuel cycles: CRP T21027 1813: Processing technologies for high level waste, formulation of matrices and characterization of waste forms, task 17208: Final report

    SciTech Connect

    Amoroso, J. W.; Marra, J. C.

    2015-08-26

    A multi-phase ceramic waste form is being developed at the Savannah River National Laboratory (SRNL) for treatment of secondary waste streams generated by reprocessing commercial spent nuclear. The envisioned waste stream contains a mixture of transition, alkali, alkaline earth, and lanthanide metals. Ceramic waste forms are tailored (engineered) to incorporate waste components as part of their crystal structure based on knowledge from naturally found minerals containing radioactive and non-radioactive species similar to the radionuclides of concern in wastes from fuel reprocessing. The ability to tailor ceramics to mimic naturally occurring crystals substantiates the long term stability of such crystals (ceramics) over geologic timescales of interest for nuclear waste immobilization [1]. A durable multi-phase ceramic waste form tailored to incorporate all the waste components has the potential to broaden the available disposal options and thus minimize the storage and disposal costs associated with aqueous reprocessing. This report summarizes results from three years of work on the IAEA Coordinated Research Project on “Processing technologies for high level waste, formulation of matrices and characterization of waste forms” (T21027), and specific task “Melt Processed Crystalline Ceramic Waste Forms for Advanced Nuclear Fuel Cycles” (17208).

  8. Nuclear waste disposal utilizing a gaseous core reactor

    NASA Technical Reports Server (NTRS)

    Paternoster, R. R.

    1975-01-01

    The feasibility of a gaseous core nuclear reactor designed to produce power to also reduce the national inventories of long-lived reactor waste products through nuclear transmutation was examined. Neutron-induced transmutation of radioactive wastes is shown to be an effective means of shortening the apparent half life.

  9. For Sale: Nuclear Waste Sites--Anyone Buying?

    ERIC Educational Resources Information Center

    Hancock, Don

    1992-01-01

    Explores why the United States Nuclear Waste Program has been unable to find a volunteer state to host either a nuclear waste repository or monitored retrieval storage facility. Discusses the Department of Energy's plans for Nevada's Yucca Mountain as a repository and state and tribal responses to the plan. (21 references) (MCO)

  10. For Sale: Nuclear Waste Sites--Anyone Buying?

    ERIC Educational Resources Information Center

    Hancock, Don

    1992-01-01

    Explores why the United States Nuclear Waste Program has been unable to find a volunteer state to host either a nuclear waste repository or monitored retrieval storage facility. Discusses the Department of Energy's plans for Nevada's Yucca Mountain as a repository and state and tribal responses to the plan. (21 references) (MCO)

  11. Validating carbonation parameters of alkaline solid wastes via integrated thermal analyses: Principles and applications.

    PubMed

    Pan, Shu-Yuan; Chang, E-E; Kim, Hyunook; Chen, Yi-Hung; Chiang, Pen-Chi

    2016-04-15

    Accelerated carbonation of alkaline solid wastes is an attractive method for CO2 capture and utilization. However, the evaluation criteria of CaCO3 content in solid wastes and the way to interpret thermal analysis profiles were found to be quite different among the literature. In this investigation, an integrated thermal analyses for determining carbonation parameters in basic oxygen furnace slag (BOFS) were proposed based on thermogravimetric (TG), derivative thermogravimetric (DTG), and differential scanning calorimetry (DSC) analyses. A modified method of TG-DTG interpretation was proposed by considering the consecutive weight loss of sample with 200-900°C because the decomposition of various hydrated compounds caused variances in estimates by using conventional methods of TG interpretation. Different quantities of reference CaCO3 standards, carbonated BOFS samples and synthetic CaCO3/BOFS mixtures were prepared for evaluating the data quality of the modified TG-DTG interpretation, in terms of precision and accuracy. The quantitative results of the modified TG-DTG method were also validated by DSC analysis. In addition, to confirm the TG-DTG results, the evolved gas analysis was performed by mass spectrometer and Fourier transform infrared spectroscopy for detection of the gaseous compounds released during heating. Furthermore, the decomposition kinetics and thermodynamics of CaCO3 in BOFS was evaluated using Arrhenius equation and Kissinger equation. The proposed integrated thermal analyses for determining CaCO3 content in alkaline wastes was precise and accurate, thereby enabling to effectively assess the CO2 capture capacity of alkaline wastes for mineral carbonation. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES

    SciTech Connect

    Nash, Kenneth L.

    2008-11-20

    In this project, both the fundamental chemistry of actinides in alkaline solutions (relevant to those present in Hanford-style waste storage tanks), and their dissolution from sludge simulants (and interactions with supernatants) have been investigated under representative sludge leaching procedures. The leaching protocols were designed to go beyond conventional alkaline sludge leaching limits, including the application of acidic leachants, oxidants and complexing agents. The simulant leaching studies confirm in most cases the basic premise that actinides will remain in the sludge during leaching with 2-3 M NaOH caustic leach solutions. However, they also confirm significant chances for increased mobility of actinides under oxidative leaching conditions. Thermodynamic data generated improves the general level of experiemental information available to predict actinide speciation in leach solutions. Additional information indicates that improved Al removal can be achieved with even dilute acid leaching and that acidic Al(NO3)3 solutions can be decontaminated of co-mobilized actinides using conventional separations methods. Both complexing agents and acidic leaching solutions have significant potential to improve the effectiveness of conventional alkaline leaching protocols. The prime objective of this program was to provide adequate insight into actinide behavior under these conditions to enable prudent decision making as tank waste treatment protocols develop.

  13. Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts

    SciTech Connect

    Levitskaia, Tatiana G.; Lumetta, Gregg J.; Moyer, Bruce A.; Bonnesen, Peter V.

    2005-06-01

    The purpose of this research involving collaboration between Oak Ridge National Laboratory (ORNL) and Pacific Northwest National Laboratory (PNNL) is to explore new approaches to the separation of sodium hydroxide, sodium nitrate, and other sodium salts from high-level alkaline tank waste. The principal potential benefit is a major reduction in disposed waste volume, obviating the building of expensive new waste tanks and reducing the costs of low-activity waste immobilization. Principles of ion recognition are being researched toward discovery of liquid-liquid extraction systems that selectively separate sodium hydroxide and sodium nitrate from other waste components. The successful concept of pseudohydroxide extraction using fluorinated alcohols and phenols is being developed at ORNL and PNNL toward a greater understanding of the controlling equilibria, role of solvation, and of synergistic effects involving crown ethers. Synthesis efforts are being directed toward enhanced sodium binding by crown ethers, both neutral and proton-ionizable. Studies with real tank waste at PNNL will provide feedback toward solvent compositions that have promising properties.

  14. Alkaline fermentation of waste sludge causes a significant reduction of antibiotic resistance genes in anaerobic reactors.

    PubMed

    Huang, Haining; Zheng, Xiong; Chen, Yinguang; Liu, Hui; Wan, Rui; Su, Yinglong

    2017-02-15

    Alkaline fermentation has been reported to be an effective method to recover valuable products from waste sludge. However, to date, the potential effect of alkaline pH on the fate of antibiotic resistance genes (ARGs) during anaerobic fermentation of sludge has never been documented. In this study, the target ARGs in sludge was observed to be removed effectively and stably when sludge was anaerobically fermented at pH10. Compared with the control (without pH adjustment), the abundances of target ARGs at pH10 were reduced by 0.87 (sulI), 1.36 (sulII), 0.42 (tet(O)), 1.11 (tet(Q)), 0.79 (tet(C)) and 1.04 (tet(X)) log units. Further investigations revealed that alkaline fermentation shifted the community structures of potential ARGs hosts. Moreover, alkaline fermentation remarkably decreased the quantities and the ARGs-possessing ability of genetic vectors (plasmid DNA, extracellular DNA and phage DNA), which might limit the transfer of ARGs via conjugation, transformation and transduction. These results suggest that the shifted compositions of gene hosts and restricted gene transfer potential might be the critical reasons for the attenuation of ARGs at pH10.

  15. Nuclear waste: Status of DOE`s nuclear waste site characterization activities

    SciTech Connect

    1987-12-31

    Three potential nuclear waste repository sites have been selected to carry out characterization activities-the detailed geological testing to determine the suitability of each site as a repository. The sites are Hanford in south-central Washington State, Yucca Mountain in southern Nevada, and Deaf Smith in the Texas Panhandle. Two key issues affecting the total program are the estimations of the site characterization completion data and costs and DOE`s relationship with the Nuclear Regulatory Commission which has been limited and its relations with affected states and Indian tribes which continue to be difficult.

  16. Nuclear waste vitrification efficiency: cold cap reactions

    SciTech Connect

    Hrma, Pavel R.; Kruger, Albert A.; Pokorny, Richard

    2012-12-15

    The cost and schedule of nuclear waste treatment and immobilization are greatly affected by the rate of glass production. Various factors influence the performance of a waste-glass melter. One of the most significant, and also one of the least understood, is the process of batch melting. Studies are being conducted to gain fundamental understanding of the batch reactions, particularly those that influence the rate of melting, and models are being developed to link batch makeup and melter operation to the melting rate. Batch melting takes place within the cold cap, i.e., a batch layer floating on the surface of molten glass. The conversion of batch to glass consists of various chemical reactions, phase transitions, and diffusion-controlled processes. These include water evaporation (slurry feed contains as high as 60% water), gas evolution, the melting of salts, the formation of borate melt, reactions of borate melt with molten salts and with amorphous oxides (Fe2O3 and Al2O3), the formation of intermediate crystalline phases, the formation of a continuous glass-forming melt, the growth and collapse of primary foam, and the dissolution of residual solids. To this list we also need to add the formation of secondary foam that originates from molten glass but accumulates on the bottom of the cold cap. This study presents relevant data obtained for a high-level-waste melter feed and introduces a one-dimensional (1D) mathematical model of the cold cap as a step toward an advanced three-dimensional (3D) version for a complete model of the waste glass melter. The 1D model describes the batch-to-glass conversion within the cold cap as it progresses in a vertical direction. With constitutive equations and key parameters based on measured data, and simplified boundary conditions on the cold-cap interfaces with the glass melt and the plenum space of the melter, the model provides sensitivity analysis of the response of the cold cap to the batch makeup and melter conditions

  17. NUCLEAR WASTE VITRIFICATION EFFICIENCY COLD CAP REACTIONS

    SciTech Connect

    KRUGER AA; HRMA PR; POKORNY R

    2011-07-29

    The cost and schedule of nuclear waste treatment and immobilization are greatly affected by the rate of glass production. Various factors influence the performance of a waste-glass melter. One of the most significant, and also one of the least understood, is the process of batch melting. Studies are being conducted to gain fundamental understanding of the batch reactions, particularly those that influence the rate of melting, and models are being developed to link batch makeup and melter operation to the melting rate. Batch melting takes place within the cold cap, i.e., a batch layer floating on the surface of molten glass. The conversion of batch to glass consists of various chemical reactions, phase transitions, and diffusion-controlled processes. These include water evaporation (slurry feed contains as high as 60% water), gas evolution, the melting of salts, the formation of borate melt, reactions of borate melt with molten salts and with amorphous oxides (Fe{sub 2}O{sub 3} and Al{sub 2}O{sub 3}), the formation of intermediate crystalline phases, the formation of a continuous glass-forming melt, the growth and collapse of primary foam, and the dissolution of residual solids. To this list we also need to add the formation of secondary foam that originates from molten glass but accumulates on the bottom of the cold cap. This study presents relevant data obtained for a high-level-waste melter feed and introduces a one-dimensional (1D) mathematical model of the cold cap as a step toward an advanced three-dimensional (3D) version for a complete model of the waste glass melter. The 1D model describes the batch-to-glass conversion within the cold cap as it progresses in a vertical direction. With constitutive equations and key parameters based on measured data, and simplified boundary conditions on the cold-cap interfaces with the glass melt and the plenum space of the melter, the model provides sensitivity analysis of the response of the cold cap to the batch makeup

  18. Dismantlement and radioactive waste management of North Korean nuclear facilities.

    SciTech Connect

    Whang, Jooho; Baldwin, George Thomas

    2004-07-01

    One critical aspect of any denuclearization of the Democratic People's Republic of Korea (DPRK) involves dismantlement of its nuclear facilities and management of their associated radioactive wastes. The decommissioning problem for its two principal operational plutonium facilities at Yongbyun, the 5MWe nuclear reactor and the Radiochemical Laboratory reprocessing facility, alone present a formidable challenge. Dismantling those facilities will create radioactive waste in addition to existing inventories of spent fuel and reprocessing wastes. Negotiations with the DPRK, such as the Six Party Talks, need to appreciate the enormous scale of the radioactive waste management problem resulting from dismantlement. The two operating plutonium facilities, along with their legacy wastes, will result in anywhere from 50 to 100 metric tons of uranium spent fuel, as much as 500,000 liters of liquid high-level waste, as well as miscellaneous high-level waste sources from the Radiochemical Laboratory. A substantial quantity of intermediate-level waste will result from disposing 600 metric tons of graphite from the reactor, an undetermined quantity of chemical decladding liquid waste from reprocessing, and hundreds of tons of contaminated concrete and metal from facility dismantlement. Various facilities for dismantlement, decontamination, waste treatment and packaging, and storage will be needed. The shipment of spent fuel and liquid high level waste out of the DPRK is also likely to be required. Nuclear facility dismantlement and radioactive waste management in the DPRK are all the more difficult because of nuclear nonproliferation constraints, including the call by the United States for 'complete, verifiable and irreversible dismantlement', or 'CVID'. It is desirable to accomplish dismantlement quickly, but many aspects of the radioactive waste management cannot be achieved without careful assessment, planning and preparation, sustained commitment, and long completion times

  19. Nuclear waste management. Quarterly progress report, April-June 1981

    SciTech Connect

    Chikalla, T.D.; Powell, J.A.

    1981-09-01

    Reports and summaries are presented for the following: high-level waste process development; alternative waste forms; TMI zeolite vitrification demonstration program; nuclear waste materials characterization center; TRU waste immobilization; TRU waste decontamination; krypton implantation; thermal outgassing; iodine-129 fixation; NWVP off-gas analysis; monitoring and physical characterization of unsaturated zone transport; well-logging instrumentation development; verification instrument development; mobility of organic complexes of radionuclides in soils; handbook of methods to decrease the generation of low-level waste; waste management system studies; waste management safety studies; assessment of effectiveness of geologic isolation systems; waste/rock interactions technology program; high-level waste form preparation; development of backfill materials; development of structural engineered barriers; disposal charge analysis; and analysis of spent fuel policy implementation.

  20. Mechanical properties of untreated and alkaline treated fibers from zalacca midrib wastes

    NASA Astrophysics Data System (ADS)

    Raharjo, Wahyu Purwo; Soenoko, Rudy; Purnowidodo, Anindito; Choiron, Mochammad Agus; Triyono

    2016-03-01

    The environmental concern has been raised due to the abundance of waste from synthetic materials which cannot be biodegraded after their life-time. It provides opportunity to exploit natural resources which are neglected. For example, midrib wastes from zalacca plants after cutting are able to utilize as composite reinforcement. The aim of this research was to characterize the mechanical properties of zalacca midrib fibers. As other ones, zalacca midrib fibers consisted of cellulose, hemicellulose and lignin, which their compositions were 42.54, 34.35 and 28.01 % respectively. To raise their cellulose content, the zalacca fibers were alkaline treated by immersion in the sodium hydroxide for 2 hours and rinsing in the distilled water. The concentration of sodium hydroxide was varied 1 and 5%. To investigate the influence of alkaline treatment, the mechanical testing and morphological analysis was performed. The tensile testing was done to obtain ultimate strength, elastic modulus and strain to fracture. The surface morphology of fibers was observed by SEM. The average ultimate tensile strength of zalacca fibers ranged from 182.12 MPa (untreated) to 417.94 MPa (5%NaOH treated). The diameter measurement showed that the alkaline treatment reduce the average fiber diameters due to the decline of the hemicellulose and lignin content as fiber matrix. This caused the increase of the tensile strength and elastic modulus due to the reduction of diameters as divider meanwhile the cellulose content as structural supporter of the fibers was relatively constant. From the SEM analysis, it was shown that the alkaline treatment reduced the fiber matrix so that its surface morphology became rougher due to the microfibrils appearance.

  1. Hydration process of nuclear-waste glass: an interim report

    SciTech Connect

    Bates, J.K.; Jardine, L.J.; Steindler, M.J.

    1982-07-01

    Aging of simulated nuclear waste glass by contact with a controlled-temperature, humid atmosphere results in the formation of a double hydration layer penetrating the glass, as well as the formation of minerals on the glass surface. The hydration process can be described by Arrhenius behavior between 120 and 240/sup 0/C. Results suggest that simulated aging reactions are necessary for demonstrating that nuclear waste forms can meet projected Nuclear Regulatory Commission regulations. 16 figures, 4 tables.

  2. A QUARTER CENTURY OF NUCLEAR WASTE MANAGEMENT IN JAPAN

    SciTech Connect

    Masuda, S.

    2002-02-25

    This paper is entitled ''A QUARTER CENTURY OF NUCLEAR WASTE MANAGEMENT IN JAPAN''. Since the first statement on the strategy for radioactive waste management in Japan was made by the Atomic Energy Commission (AEC) in 1976, a quarter century has passed, in which much experience has been accumulated both in technical and social domains. This paper looks back in this 25-year history of radioactive waste management in Japan by highlighting activities related to high-level radioactive waste (HLW) disposal.

  3. Method of preparing nuclear wastes for tansportation and interim storage

    DOEpatents

    Bandyopadhyay, Gautam; Galvin, Thomas M.

    1984-01-01

    Nuclear waste is formed into a substantially water-insoluble solid for temporary storage and transportation by mixing the calcined waste with at least 10 weight percent powdered anhydrous sodium silicate to form a mixture and subjecting the mixture to a high humidity environment for a period of time sufficient to form cementitious bonds by chemical reaction. The method is suitable for preparing an interim waste form from dried high level radioactive wastes.

  4. Nuclear waste storage container with metal matrix

    DOEpatents

    Sump, Kenneth R.

    1978-01-01

    The invention relates to a storage container for high-level waste having a metal matrix for the high-level waste, thereby providing greater impact strength for the waste container and increasing heat transfer properties.

  5. Materials Science of High-Level Nuclear Waste Immobilization

    SciTech Connect

    Weber, William J.; Navrotsky, Alexandra; Stefanovsky, S. V.; Vance, E. R.; Vernaz, Etienne Y.

    2009-01-09

    With the increasing demand for the development of more nuclear power comes the responsibility to address the technical challenges of immobilizing high-level nuclear wastes in stable solid forms for interim storage or disposition in geologic repositories. The immobilization of high-level nuclear wastes has been an active area of research and development for over 50 years. Borosilicate glasses and complex ceramic composites have been developed to meet many technical challenges and current needs, although regulatory issues, which vary widely from country to country, have yet to be resolved. Cooperative international programs to develop advanced proliferation-resistant nuclear technologies to close the nuclear fuel cycle and increase the efficiency of nuclear energy production might create new separation waste streams that could demand new concepts and materials for nuclear waste immobilization. This article reviews the current state-of-the-art understanding regarding the materials science of glasses and ceramics for the immobilization of high-level nuclear waste and excess nuclear materials and discusses approaches to address new waste streams.

  6. Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts

    SciTech Connect

    Moyer, Bruce A.; Bonnesen, Peter V.; Custelcean, Radu; Delmau, Laetitia H.; Engle, Nancy L.; Kang, Hyun-Ah; Keever, Tamara J.; Marchand, Alan P.; Gadthula, Srinivas; Gore, Vinayak K.; Huang, Zilin; Sivappa, Rasapalli; Tirunahari, Pavan K.; Levitskaia, Tatiana G.; Lumetta, Gregg J.

    2005-09-26

    The purpose of this research involving collaboration between Oak Ridge National Laboratory (ORNL) and Pacific Northwest National Laboratory (PNNL) is to explore new approaches to the separation of sodium hydroxide, sodium nitrate, and other sodium salts from high-level alkaline tank waste. The principal potential benefit is a major reduction in disposed waste volume, obviating the building of expensive new waste tanks and reducing the costs of vitrification. Principles of ion recognition are being researched toward discovery of liquid-liquid extraction systems that selectively separate sodium hydroxide and sodium nitrate from other waste components. The successful concept of pseudo hydroxide extraction using fluorinated alcohols and phenols is being developed at ORNL and PNNL toward a greater understanding of the controlling equilibria, role of solvation, and of synergistic effects involving crown ethers. Synthesis efforts are being directed toward enhanced sodium binding by crown ethers, both neutral and proton-ionizable. Studies with real tank waste at PNNL will provide feedback toward solvent compositions that have promising properties.

  7. Evaluation of New Inorganic Sorbents for Strontium and Actinide Removal from High-Level Nuclear Waste Solutions

    SciTech Connect

    Hobbs, D.T.; Nyman, M.; Medvedev, D.G.; Tripathi, A.; Clearfield, A.

    2004-03-28

    Monosodium titanate (MST), a hydrous metal oxide sorbent, is the baseline material for the removal of 90Sr and alpha-emitting radionuclides (principally 238Pu, 239Pu, 240Pu and 237Np) from alkaline waste solutions generated during the processing of irradiated nuclear materials at the Savannah River Site. This material exhibits excellent performance characteristics for strontium removal. Plutonium removal is also good, but problematic at the estimated bonding concentration. We are currently developing new inorganic materials for improved sorption characteristics. These materials include sodium nonatitanates, pharmacosiderites and heteropolyniobates. We will present results evaluating the performance of these materials with simulated and actual high level nuclear waste solutions.

  8. Depleted uranium as a backfill for nuclear fuel waste package

    DOEpatents

    Forsberg, C.W.

    1998-11-03

    A method is described for packaging spent nuclear fuel for long-term disposal in a geological repository. At least one spent nuclear fuel assembly is first placed in an unsealed waste package and a depleted uranium fill material is added to the waste package. The depleted uranium fill material comprises flowable particles having a size sufficient to substantially fill any voids in and around the assembly and contains isotopically-depleted uranium in the +4 valence state in an amount sufficient to inhibit dissolution of the spent nuclear fuel from the assembly into a surrounding medium and to lessen the potential for nuclear criticality inside the repository in the event of failure of the waste package. Last, the waste package is sealed, thereby substantially reducing the release of radionuclides into the surrounding medium, while simultaneously providing radiation shielding and increased structural integrity of the waste package. 6 figs.

  9. Depleted uranium as a backfill for nuclear fuel waste package

    SciTech Connect

    Forsberg, Charles W.

    1997-12-01

    A method is described for packaging spent nuclear fuel for long-term disposal in a geological repository. At least one spent nuclear fuel assembly is first placed in an unsealed waste package and a depleted uranium fill material is added to the waste package. The depleted uranium fill material comprises flowable particles having a size sufficient to substantially fill any voids in and around the assembly and contains isotonically-depleted uranium in the +4 valence state in an amount sufficient to inhibit dissolution of the spent nuclear fuel from the assembly into a surrounding medium and to lessen the potential for nuclear criticality inside the repository in the event of failure of the waste package. Last, the waste package is sealed, thereby substantially reducing the release of radionuclides into the surrounding medium, while simultaneously providing radiation shielding and increased structural integrity of the waste package.

  10. Depleted uranium as a backfill for nuclear fuel waste package

    DOEpatents

    Forsberg, Charles W.

    1998-01-01

    A method for packaging spent nuclear fuel for long-term disposal in a geological repository. At least one spent nuclear fuel assembly is first placed in an unsealed waste package and a depleted uranium fill material is added to the waste package. The depleted uranium fill material comprises flowable particles having a size sufficient to substantially fill any voids in and around the assembly and contains isotopically-depleted uranium in the +4 valence state in an amount sufficient to inhibit dissolution of the spent nuclear fuel from the assembly into a surrounding medium and to lessen the potential for nuclear criticality inside the repository in the event of failure of the waste package. Last, the waste package is sealed, thereby substantially reducing the release of radionuclides into the surrounding medium, while simultaneously providing radiation shielding and increased structural integrity of the waste package.

  11. Nuclear Waste Management Program summary document, FY 1981

    SciTech Connect

    Meyers, Sheldon

    1980-03-01

    The Nuclear Waste Management Program Summary Document outlines the operational and research and development (R and D) activities of the Office of Nuclear Waste Management (NEW) under the Assistant Secretary for Nuclear Energy, US Department of Energy (DOE). This document focuses on the current and planned activities in waste management for FY 1981. This Program Summary Document (PSD) was prepared in order to explain the Federal nuclear waste management and spent fuel storage programs to Congress and its committees and to interested members of the public, the private sector, and the research community. The national energy policy as it applies to waste management and spent fuel storage is presented first. The program strategy, structure, budget, management approach, and public participation programs are then identified. The next section describes program activities and outlines their status. Finally, the applicability of departmental policies to NEW programs is summarized, including field and regional activities, commercialization plans, and environmental and socioeconomic implications of waste management activities, and international programs. This Nuclear Waste Management Program Summary Document is meant to serve as a guide to the progress of R and D and other energy technology programs in radioactive waste management. The R and D objective is to provide the Nation with acceptable solutions to short- and long-term management problems for all forms of radioactive waste and spent fuel.

  12. Nuclear waste treatment program: Annual report for FY 1987

    SciTech Connect

    Brouns, R.A.; Powell, J.A.

    1988-09-01

    Two of the US Department of Energy's (DOE) nuclear waste management-related goals are to ensure that waste management is not an obstacle to the further development of light-water reactors and the closure of the nuclear fuel cycle and to fulfill its institutional responsibility for providing safe storage and disposal of existing and future nuclear wastes. As part of its approach to achieving these goals, the Office of Remedial Action and Waste Technology of DOE established what is now called the Nuclear Waste Treatment Program (NWTP) at the Pacific Northwest Laboratory during the second half of FY 1982. To support DOE's attainment of its goals, the NWTP is to provide technology necessary for the design and operation of nuclear waste treatment facilities by commercial enterprises as part of a licensed waste management system and problem-specific treatment approaches, waste form and treatment process adaptations, equipment designs, and trouble-shooting assistance, as required to treat existing wastes. This annual report describes progress during FY 1987 towards meeting these two objectives. 24 refs., 59 figs., 24 tabs.

  13. Nuclear hazardous waste cost control management

    SciTech Connect

    Selg, R.A.

    1991-05-09

    The effects of the waste content of glass waste forms on Savannah River high-level waste disposal costs are currently under study to adjust the glass frit content to optimize the glass waste loadings and therefore significantly reduce the overall waste disposal cost. Changes in waste content affect onsite Defense Waste Changes in waste contents affect onsite Defense Waste Processing Facility (DWPF) costs as well as offsite shipping and repository emplacement charges. A nominal 1% increase over the 28 wt% waste loading of DWPF glass would reduce disposal costs by about $50 million for Savannah River wastes generated to the year 2000. Optimization of the glass waste forms to be produced in the SWPF is being supported by economic evaluations of the impact of the forms on waste disposal costs. Glass compositions are specified for acceptable melt processing and durability characteristics, with economic effects tracked by the number of waste canisters produced. This paper presents an evaluation of the effects of variations in waste content of the glass waste forms on the overall cost of the disposal, including offsite shipment and repository emplacement, of the Savannah River high-level wastes.

  14. Alkaline-side extraction of technetium from tank waste using crown ethers and other extractants

    SciTech Connect

    Bonnesen, P.V.; Moyer, B.A.; Presley, D.J.; Armstrong, V.S.; Haverlock, T.J.; Counce, R.M.; Sachleben, R.A.

    1996-06-01

    The chemical development of a new crown-ether-based solvent-extraction process for the separation of (Tc) from alkaline tank-waste supernate is ready for counter-current testing. The process addresses a priority need in the proposed cleanup of Hanford and other tank wastes. This need has arisen from concerns due to the volatility of Tc during vitrification, as well as {sup 99}Tc`s long half-life and environmental mobility. The new process offers several key advantages that direct treatability--no adjustment of the waste composition is needed; economical stripping with water; high efficiency--few stages needed; non-RCRA chemicals--no generation of hazardous or mixed wastes; co-extraction of {sup 90}Sr; and optional concentration on a resin. A key concept advanced in this work entails the use of tandem techniques: solvent extraction offers high selectivity, while a subsequent column sorption process on the aqueous stripping solution serves to greatly concentrate the Tc. Optionally, the stripping solution can be evaporated to a small volume. Batch tests of the solvent-extraction and stripping components of the process have been conducted on actual melton Valley Storage Tank (MVST) waste as well as simulants of MVST and Hanford waste. The tandem process was demonstrated on MVST waste simulants using the three solvents that were selected the final candidates for the process. The solvents are 0.04 M bis-4,4{prime}(5{prime})[(tert-butyl)cyclohexano]-18-crown-6 (abbreviated di-t-BuCH18C6) in a 1:1 vol/vol blend of tributyl phosphate and Isopar{reg_sign} M (an isoparaffinic kerosene); 0.02 M di-t-BuCH18C6 in 2:1 vol/vol TBP/Isopar M and pure TBP. The process is now ready for counter-current testing on actual Hanford tank supernates.

  15. Comparison of alkaline industrial wastes for aqueous mineral carbon sequestration through a parallel reactivity study.

    PubMed

    Noack, Clinton W; Dzombak, David A; Nakles, David V; Hawthorne, Steven B; Heebink, Loreal V; Dando, Neal; Gershenzon, Michael; Ghosh, Rajat S

    2014-10-01

    Thirty-one alkaline industrial wastes from a wide range of industrial processes were acquired and screened for application in an aqueous carbon sequestration process. The wastes were evaluated for their potential to leach polyvalent cations and base species. Following mixing with a simple sodium bicarbonate solution, chemistries of the aqueous and solid phases were analyzed. Experimental results indicated that the most reactive materials were capable of sequestering between 77% and 93% of the available carbon under experimental conditions in four hours. These materials - cement kiln dust, spray dryer absorber ash, and circulating dry scrubber ash - are thus good candidates for detailed, process-oriented studies. Chemical equilibrium modeling indicated that amorphous calcium carbonate is likely responsible for the observed sequestration. High variability and low reactive fractions render many other materials less attractive for further pursuit without considering preprocessing or activation techniques. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Nuclear waste management. Quarterly progress report, April-June 1980

    SciTech Connect

    Platt, A.M.; Powell, J.A.

    1980-09-01

    The status of the following programs is reported: high-level waste immobilization; alternative waste forms; Nuclear Waste Materials Characterization Center; TRU waste immobilization; TRU waste decontamination; krypton solidification; thermal outgassing; iodine-129 fixation; monitoring and physical characterization of unsaturated zone transport; well-logging instrumentation development; mobility of organic complexes of fission products in soils; waste management system studies; waste management safety studies; assessment of effectiveness of geologic isolation systems; waste/rock interactions technology; systems study on engineered barriers; criteria for defining waste isolation; spent fuel and fuel pool component integrity program; analysis of spent fuel policy implementation; asphalt emulsion sealing of uranium tailings; application of long-term chemical biobarriers for uranium tailings; and development of backfill material.

  17. Nuclear waste management. Quarterly progress report, October through December 1980

    SciTech Connect

    Chikalla, T.D.; Powell, J.A.

    1981-03-01

    Progress reports and summaries are presented under the following headings: high-level waste process development; alternative waste forms; nuclear waste materials characterization center; TRU waste immobilization; TRU waste decontamination; krypton solidification; thermal outgassing; iodine-129 fixation; monitoring and physical characterization of unsaturated zone transport; well-logging instrumentation development; mobility of organic complexes of radionuclides in soils; waste management system studies; waste management safety studies; assessment of effectiveness of geologic isolation systems; waste/rock interactions technology; high level waste form preparation; development of backfill material; development of structural engineered barriers; ONWI disposal charge analysis; spent fuel and fuel component integrity program; analysis of spent fuel policy implementation; analysis of postulated criticality events in a storage array of spent LWR fuel; asphalt emulsion sealing of uranium tailings; liner evaluation for uranium mill tailings; multilayer barriers for sealing of uranium tailings; application of long-term chemical biobarriers for uranium tailings; revegetation of inactive uranium tailing sites; verification instrument development.

  18. Idaho Nuclear Technology and Engineering Center (INTEC) Sodium Bearing Waste - Waste Incidental to Reprocessing Determination

    SciTech Connect

    Jacobson, Victor Levon

    2002-08-01

    U.S. Department of Energy Manual 435.1-1, Radioactive Waste Management, Section I.1.C, requires that all radioactive waste subject to Department of Energy Order 435.1 be managed as high-level radioactive waste, transuranic waste, or low-level radioactive waste. Determining the radiological classification of the sodium-bearing waste currently in the Idaho Nuclear Technology and Engineering Center Tank Farm Facility inventory is important to its proper treatment and disposition. This report presents the technical basis for making the determination that the sodium-bearing waste is waste incidental to spent fuel reprocessing and should be managed as mixed transuranic waste. This report focuses on the radiological characteristics of the sodiumbearing waste. The report does not address characterization of the nonradiological, hazardous constituents of the waste in accordance with Resource Conservation and Recovery Act requirements.

  19. Electrolytic recycling of a carbonate salt in a process with a dissolution of spent nuclear fuel in a strong alkaline carbonate media

    SciTech Connect

    Kwang-Wook Kim; In-Tae Kim; Seong-Min Kim; Yeon-Hwa Kim; Eil-Hee Lee; Kwang-Yong Jee

    2007-07-01

    A removal of only uranium from spent nuclear fuel with the concepts of a high proliferation-resistance and a minimal generation of waste is helpful for a spent fuel management in view of a volume reduction of the high level radioactive waste generated from the spent fuel treatment. That can be accomplished by a process using a selective oxidative dissolution of the spent fuel in a carbonate solution of high alkalinity. In this work, an electrolytic method for a de-carbonation and a recovery of CO{sub 2} for recycling the used carbonate solution contaminated with some impurity metal ions generated in such a process with a concept of zero-release of waste solution was studied. A carbonate solution generated from such a system was confirmed to be completely recycled within the system, while the impurity ions being separated from the carbonate solution. (authors)

  20. Heavy metals stabilization in medical waste incinerator fly ash using alkaline assisted supercritical water technology.

    PubMed

    Jin, Jian; Li, Xiaodong; Chi, Yong; Yan, Jianhua

    2010-12-01

    This study investigated the process of aluminosilicate formation in medical waste incinerator fly ash containing large amounts of heavy metals and treated with alkaline compounds at 375 degrees C and examined how this process affected the mobility and availability of the metals. As a consequence of the treatments, the amount of dissolved heavy metals, and thus their mobility, was greatly reduced, and the metal leaching concentration was below the legislative regulations for metal leachability. Moreover, this process did not produce a high concentration of heavy metals in the effluent. The addition of alkaline compounds such as sodium hydroxide and sodium carbonate can prevent certain heavy metal ions dissolving in water. In comparison with the alkaline-free condition, the extracted concentrations of As, Mn, Pb, Sr and Zn were decreased by about 51.08, 97.22, 58.33, 96.77 and 86.89% by the addition of sodium hydroxide and 66.18, 86.11, 58.33, 83.87 and 81.91% by the addition of sodium carbonate. A mechanism for how the formation of aluminosilicate occurred in supercritical water and affected the mobility and availability of the heavy metals is discussed. The reported results could be useful as basic knowledge for planning new technologies for the hydrothermal stabilization of heavy metals in fly ash.

  1. Biodegradation of the alkaline cellulose degradation products generated during radioactive waste disposal.

    PubMed

    Rout, Simon P; Radford, Jessica; Laws, Andrew P; Sweeney, Francis; Elmekawy, Ahmed; Gillie, Lisa J; Humphreys, Paul N

    2014-01-01

    The anoxic, alkaline hydrolysis of cellulosic materials generates a range of cellulose degradation products (CDP) including α and β forms of isosaccharinic acid (ISA) and is expected to occur in radioactive waste disposal sites receiving intermediate level radioactive wastes. The generation of ISA's is of particular relevance to the disposal of these wastes since they are able to form complexes with radioelements such as Pu enhancing their migration. This study demonstrates that microbial communities present in near-surface anoxic sediments are able to degrade CDP including both forms of ISA via iron reduction, sulphate reduction and methanogenesis, without any prior exposure to these substrates. No significant difference (n = 6, p = 0.118) in α and β ISA degradation rates were seen under either iron reducing, sulphate reducing or methanogenic conditions, giving an overall mean degradation rate of 4.7 × 10(-2) hr(-1) (SE ± 2.9 × 10(-3)). These results suggest that a radioactive waste disposal site is likely to be colonised by organisms able to degrade CDP and associated ISA's during the construction and operational phase of the facility.

  2. Biodegradation of the Alkaline Cellulose Degradation Products Generated during Radioactive Waste Disposal

    PubMed Central

    Rout, Simon P.; Radford, Jessica; Laws, Andrew P.; Sweeney, Francis; Elmekawy, Ahmed; Gillie, Lisa J.; Humphreys, Paul N.

    2014-01-01

    The anoxic, alkaline hydrolysis of cellulosic materials generates a range of cellulose degradation products (CDP) including α and β forms of isosaccharinic acid (ISA) and is expected to occur in radioactive waste disposal sites receiving intermediate level radioactive wastes. The generation of ISA's is of particular relevance to the disposal of these wastes since they are able to form complexes with radioelements such as Pu enhancing their migration. This study demonstrates that microbial communities present in near-surface anoxic sediments are able to degrade CDP including both forms of ISA via iron reduction, sulphate reduction and methanogenesis, without any prior exposure to these substrates. No significant difference (n = 6, p = 0.118) in α and β ISA degradation rates were seen under either iron reducing, sulphate reducing or methanogenic conditions, giving an overall mean degradation rate of 4.7×10−2 hr−1 (SE±2.9×10−3). These results suggest that a radioactive waste disposal site is likely to be colonised by organisms able to degrade CDP and associated ISA's during the construction and operational phase of the facility. PMID:25268118

  3. Influence of Acidic and Alkaline Waste Solution Properties on Uranium Migration in Subsurface Sediments

    SciTech Connect

    Szecsody, James E.; Truex, Michael J.; Qafoku, Nikolla; Wellman, Dawn M.; Resch, Charles T.; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments has significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH 2) resulted in a rapid (< 10 h) increase in aqueous carbonate (with Ca2+, Mg2+) and phosphate and a slow (100s of hours) increase in silica, Al3+, and K+, likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH 13) resulted in a rapid (< 10 h) increase in carbonate, followed by a slow (10s to 100s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity.

  4. Influence of acidic and alkaline waste solution properties on uranium migration in subsurface sediments

    NASA Astrophysics Data System (ADS)

    Szecsody, Jim E.; Truex, Mike J.; Qafoku, Nikolla P.; Wellman, Dawn M.; Resch, Tom; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments have significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100 s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH 2) resulted in a rapid (< 10 h) increase in aqueous carbonate (with Ca2 +, Mg2 +) and phosphate and a slow (100 s of hours) increase in silica, Al3 +, and K+, likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH 13) resulted in a rapid (< 10 h) increase in carbonate, followed by a slow (10 s to 100 s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in not only uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity.

  5. Use of alkaline aluminum-containing waste products of industrial plants for waste-water treatment

    SciTech Connect

    Shut'ko, A.P.; Butchenko, L.I.

    1987-10-20

    The aim of this work was to investigate the coagulating power of sodium aluminate, and to determine the optimum dose of the reagent and pH range of the water being purified. A solution of sodium aluminate, 0.5 M as Al/sub 2/O/sub 3/, was used, prepared by dissolving aluminum metal in concentrated alkali solution. The pH of the solution obtained was 13.80 at 20/sub 0/, and the alkalinity, determined by titration of the sodium aluminate with 0.1 M hydrochloric acid solution with the use of bromophenol blue as indicator, was 3.75 g-eq/liter. The industrial coagulant used was spent solution from processes of chemical scouring of aluminum and its alloys, containing 40 g/liter of aluminum, with a pH of 13.86 and an alkalinity of 7.5 g-eq/liter. It was determined that the optimum doses were 60-90 mg/liter as Al/sub 2/O/sub 3/. The criteria of good coagulation were a formation, during 1 min, of coarse rapidly setting flakes of aluminum hydroxide, and a low residual aluminum content not exceeding 0.5 mg/liter.

  6. Can clays ensure nuclear waste repositories?

    NASA Astrophysics Data System (ADS)

    Zaoui, A.; Sekkal, W.

    2015-03-01

    Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation.

  7. Can clays ensure nuclear waste repositories?

    PubMed Central

    Zaoui, A.; Sekkal, W.

    2015-01-01

    Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation. PMID:25742950

  8. Irradiated Nuclear Fuel Management: Resource Versus Waste

    SciTech Connect

    Nash, Kenneth L.; Lumetta, Gregg J.; Vienna, John D.

    2013-01-01

    Management of irradiated fuel is an important component of commercial nuclear power production. Although it is broadly agreed that the disposition of some fraction of the fuel in geological repositories will be necessary, there is a range of options that can be considered that affect exactly what fraction of material will be disposed in that manner. Furthermore, until geological repositories are available to accept commercial irradiated fuel, these materials must be safely stored. Temporary storage of irradiated fuel has traditionally been conducted in storage pools, and this is still true for freshly discharged fuel. Criticality control technologies have led to greater efficiencies in packing of irradiated fuel into storage pools. With continued delays in establishing permanent repositories, utilities have begun to move some of the irradiated fuel inventory into dry storage. Fuel cycle options being considered worldwide include the once-through fuel cycle, limited recycle in which U and Pu are recycled back to power reactors as mixed oxide fuel, and advance partitioning and transmutation schemes designed to reduce the long term hazards associated with geological disposal from millions of years to a few hundred years. Each of these options introduces specific challenges in terms of the waste forms required to safely immobilize the hazardous components of irradiated fuel.

  9. Can clays ensure nuclear waste repositories?

    PubMed

    Zaoui, A; Sekkal, W

    2015-03-06

    Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation.

  10. [The role of the operator of nuclear power plants in disposal of nuclear waste].

    PubMed

    Chaussade, J P

    1995-03-15

    Public opinion polls show that the French have largely understood the importance of our nuclear programme in maintaining French independence with regard to power supply and its security and that they have confidence in the technicians for the proper construction and operation of these power plants, but that they retain many questions concerning the disposal of nuclear waste. They have the impression that solutions remain to be found, and especially that the Electricité de France (EDF) devised the nuclear power programme without concern for the disposal of waste. This lack of information is fortunately far from reality. EDF, under the supervision of the security authorities, manages the waste produced in the nuclear power plants. Final stocking of waste is handled by a body that is independent of the waste producer, the "Agence nationale pour la gestion des déchets radioadctifs" (Andra) (National Agency for the Management of Radioactive Waste).

  11. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... notification of shipment of irradiated reactor fuel and nuclear waste. (a)(1) As specified in paragraphs (b... shipment of irradiated reactor fuel or nuclear waste must contain the following information: (1) The name... nuclear waste shipment; (2) A description of the irradiated reactor fuel or nuclear waste contained in...

  12. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... notification of shipment of irradiated reactor fuel and nuclear waste. (a)(1) As specified in paragraphs (b... shipment of irradiated reactor fuel or nuclear waste must contain the following information: (1) The name... nuclear waste shipment; (2) A description of the irradiated reactor fuel or nuclear waste contained in...

  13. Iron Phosphate Glasses: An Alternative for Vitrifying Certain Nuclear Wastes

    SciTech Connect

    Delbert E. Day; Chandra S. Ray; Cheol-Woon Kim

    2004-12-28

    Vitrification of nuclear waste in a glass is currently the preferred process for waste disposal. DOE currently approves only borosilicate (BS) type glasses for such purposes. However, many nuclear wastes, presently awaiting disposal, have complex and diverse chemical compositions, and often contain components that are poorly soluble or chemically incompatible in BS glasses. Such problematic wastes can be pre-processed and/or diluted to compensate for their incompatibility with a BS glass matrix, but both of these solutions increases the wasteform volume and the overall cost for vitrification. Direct vitrification using alternative glasses that utilize the major components already present in the waste is preferable, since it avoids pre-treating or diluting the waste, and, thus, minimizes the wasteform volume and overall cost.

  14. Nuclear waste/nuclear power: their futures are linked

    SciTech Connect

    Skoblar, L.T.

    1981-01-01

    This paper briefly reviews current aspects of radioactive waste disposal techniques and transportation. Addressed are high-level and low-level radioactive wastes, interim spent fuel storage and transportation. The waste options being explored by DOE are listed. Problems of public acceptance will be more difficult to overcome than technical problems. (DMC)

  15. High level nuclear waste treatment in the Defense Waste Processing Facility: Overview and integrated flowsheet model

    SciTech Connect

    Choi, A.S.; Fowler, J.R.; Edwards, R.E. Jr.; Randall, C.T.

    1991-01-01

    Design and construction of the world's largest vitrification facility for high level nuclear waste has been nearly completed at the US Department of Energy's Savannah River Site. Equipment testing and calibration are currently being performed in preparation for the nonradioactive Chemical Runs in the late 1991. In 1993, the Defense Waste Processing Facility (DWPF) will begin producing 100 kg/hr of radioactive waste glass at 28 wt% waste oxide loading. This paper describes all phases of waste processing operations in DWPF and waste tank farms using the integrated flowsheet modeling approach. Particular emphases are given to recent developments in the DWPF processes and design.

  16. High level nuclear waste treatment in the Defense Waste Processing Facility: Overview and integrated flowsheet model

    SciTech Connect

    Choi, A.S.; Fowler, J.R.; Edwards, R.E. Jr.; Randall, C.T.

    1991-12-31

    Design and construction of the world`s largest vitrification facility for high level nuclear waste has been nearly completed at the US Department of Energy`s Savannah River Site. Equipment testing and calibration are currently being performed in preparation for the nonradioactive Chemical Runs in the late 1991. In 1993, the Defense Waste Processing Facility (DWPF) will begin producing 100 kg/hr of radioactive waste glass at 28 wt% waste oxide loading. This paper describes all phases of waste processing operations in DWPF and waste tank farms using the integrated flowsheet modeling approach. Particular emphases are given to recent developments in the DWPF processes and design.

  17. Method for calcining nuclear waste solutions containing zirconium and halides

    DOEpatents

    Newby, Billie J.

    1979-01-01

    A reduction in the quantity of gelatinous solids which are formed in aqueous zirconium-fluoride nuclear reprocessing waste solutions by calcium nitrate added to suppress halide volatility during calcination of the solution while further suppressing chloride volatility is achieved by increasing the aluminum to fluoride mole ratio in the waste solution prior to adding the calcium nitrate.

  18. Nuclear Waste Cross Site Transfer Pump Operational Resonance Resolution

    SciTech Connect

    HAUCK, F.M.

    1999-12-01

    Two single-volute, multi-stage centrifugal pumps are installed at a nuclear waste transfer station operated by the Department of Energy in Hanford, WA. The two parallel 100% pumps are Variable Frequency Drive operated and designed to transport waste etc.

  19. Method for forming microspheres for encapsulation of nuclear waste

    DOEpatents

    Angelini, Peter; Caputo, Anthony J.; Hutchens, Richard E.; Lackey, Walter J.; Stinton, David P.

    1984-01-01

    Microspheres for nuclear waste storage are formed by gelling droplets containing the waste in a gelation fluid, transferring the gelled droplets to a furnace without the washing step previously used, and heating the unwashed gelled droplets in the furnace under temperature or humidity conditions that result in a substantially linear rate of removal of volatile components therefrom.

  20. Modeling transient heat transfer in nuclear waste repositories.

    PubMed

    Yang, Shaw-Yang; Yeh, Hund-Der

    2009-09-30

    The heat of high-level nuclear waste may be generated and released from a canister at final disposal sites. The waste heat may affect the engineering properties of waste canisters, buffers, and backfill material in the emplacement tunnel and the host rock. This study addresses the problem of the heat generated from the waste canister and analyzes the heat distribution between the buffer and the host rock, which is considered as a radial two-layer heat flux problem. A conceptual model is first constructed for the heat conduction in a nuclear waste repository and then mathematical equations are formulated for modeling heat flow distribution at repository sites. The Laplace transforms are employed to develop a solution for the temperature distributions in the buffer and the host rock in the Laplace domain, which is numerically inverted to the time-domain solution using the modified Crump method. The transient temperature distributions for both the single- and multi-borehole cases are simulated in the hypothetical geological repositories of nuclear waste. The results show that the temperature distributions in the thermal field are significantly affected by the decay heat of the waste canister, the thermal properties of the buffer and the host rock, the disposal spacing, and the thickness of the host rock at a nuclear waste repository.

  1. Benefits and risks of P & T of nuclear waste

    SciTech Connect

    Abrahams, K.

    1995-10-01

    Efforts on waste transmutation are coordinated in a research programme called RAS. One of the aims of this RAS program is to inform the public and advise the authorities on methods for transmutation/conditioning of nuclear waste, and on techniques which are being developed. Such new procedures for the treatment of waste should of course not lead to significant risks for the present population. Small risks might be accepted, but these should sufficiently be compensated for by favours to future generations.

  2. Lessons in waste minimization from nuclear industry experience

    SciTech Connect

    Devgun, J.S.; Thuot, J.R.; Vrtis, J.

    1996-07-01

    The nuclear power industry has been very successful at reducing waste volumes and waste sources. The success has been driven by escalating cost, decreasing disposal ability, and a desire by the industry to achieve excellence. The result has been a cycle of continuing improvement resulting in reduced cost. Many of the examples of Dry Active Waste reduction are applicable to the Department of Energy in both operations and remedial activities. This paper discusses several successful examples of utility applications in this area.

  3. Process to separate transuranic elements from nuclear waste

    DOEpatents

    Johnson, Terry R.; Ackerman, John P.; Tomczuk, Zygmunt; Fischer, Donald F.

    1989-01-01

    A process for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR).

  4. Microbial Effects on Nuclear Waste Packaging Materials

    SciTech Connect

    Horn, J; Martin, S; Carrillo, C; Lian, T

    2005-07-22

    Microorganisms may enhance corrosion of components of planned engineered barriers within the proposed nuclear waste repository at Yucca Mountain (YM). Corrosion could occur either directly, through processes collectively known as Microbiologically Influenced Corrosion (MIC), or indirectly, by adversely affecting the composition of water or brines that come into direct contact with engineered barrier surfaces. Microorganisms of potential concern (bacteria, archea, and fungi) include both those indigenous to Yucca Mountain and those that infiltrate during repository construction and after waste emplacement. Specific aims of the experimental program to evaluate the potential of microorganisms to affect damage to engineered barrier materials include the following: Indirect Effects--(1) Determine the limiting factors to microbial growth and activity presently in the YM environment. (2) Assess these limiting factors to aid in determining the conditions and time during repository evolution when MIC might become operant. (3) Evaluate present bacterial densities, the composition of the YM microbial community, and determining bacterial densities if limiting factors are overcome. During a major portion of the regulatory period, environmental conditions that are presently extant become reestablished. Therefore, these studies ascertain whether biomass is sufficient to cause MIC during this period and provide a baseline for determining the types of bacterial activities that may be expected. (4) Assess biogenic environmental effects, including pH, alterations to nitrate concentration in groundwater, the generation of organic acids, and metal dissolution. These factors have been shown to be those most relevant to corrosion of engineered barriers. Direct Effects--(1) Characterize and quantify microbiological effects on candidate containment materials. These studies were carried out in a number of different approaches, using whole YM microbiological communities, a subset of YM

  5. Nuclear physics information needed for accelerator driven transmutation of nuclear waste

    SciTech Connect

    Lisowski, P.W.; Bowman, C.D.; Arthur, E.D.; Young, P.G.

    1991-01-01

    There is renewed interest in using accelerator driven neutron sources to address the problem of high-level long-lived nuclear waste. Several laboratories have developed systems that may have a significant impact on the future use of nuclear power, adding options for dealing with long-lived actinide wastes and fission products, and for power production. This paper describes a new Los Alamos concept using thermal neutrons and examines the nuclear data requirements. 7 refs., 3 figs., 1 tab.

  6. Technetium removal column flow testing with alkaline, high salt, radioactive tank waste

    SciTech Connect

    Blanchard, D.L. Jr.; Kurath, D.E.; Golcar, G.R.; Conradson, S.D.

    1996-09-30

    This report describes two bench-scale column tests conducted to demonstrate the removal of Tc-99 from actual alkaline high salt radioactive waste. The waste used as feed for these tests was obtained from the Hanford double shell tank AW-101, which contains double shell slurry feed (DSSF). The tank sample was diluted to approximately 5 M Na with water, and most of the Cs-137 was removed using crystalline silicotitanates. The tests were conducted with two small columns connected in series, containing, 10 mL of either a sorbent, ABEC 5000 (Eichrom Industries, Inc.), or an anion exchanger Reillex{trademark}-HPQ (Reilly Industries, Inc.). Both materials are selective for pertechnetate anion (TcO{sub 4}{sup -}). The process steps generally followed those expected in a full-scale process and included (1) resin conditioning, (2) loading, (3) caustic wash to remove residual feed and prevent the precipitation of Al(OH){sub 3}, and (4) elution. A small amount of Tc-99m tracer was added as ammonium pertechnetate to the feed and a portable GEA counter was used to closely monitor the process. Analyses of the Tc-99 in the waste was performed using ICP-MS with spot checks using radiochemical analysis. Technetium x-ray absorption spectroscopy (XAS) spectra of 6 samples were also collected to determine the prevalence of non-pertechnetate species [e.g. Tc(IV)].

  7. Technetium recovery from high alkaline solution

    SciTech Connect

    Nash, Charles A.

    2016-07-12

    Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

  8. Spherical tokamak (ST) transmutation of nuclear wastes

    SciTech Connect

    Peng, Yueng Kay Martin; Cheng, E.T.; Galambos, John D; Cerbone, R. J.

    1995-01-01

    The concept for an ST fusion core that drives a He-cooled, actinide-bearing, molten-salt blanket of moderate power density to generate electricity is examined for the first time. The results show that the fusion core is suited for this purpose and require a level of plasma, power density, engineering, and material performances moderate in comparison with what has been considered desirable for fusion-only power plants. The low aspect ratio of ST introduces a relatively thick, diverted scrape-off layer which leads to reduced heat fluxes at the limiter and divertor tiles. The use of a demountable, water-cooled, single-turn copper center leg for the toroidal field coils enables simplifications of the fusion core configuration and improves overall practicality for future power applications. These result in much reduced size and cost of the fusion core for the transmutation power plant relative to an optimized fusion-only fusion core. Surrounded by a separate tritium-breeding zone, the molten-salt blanket concept is in principle less complex and costly than the thermal breeding blankets for fusion. These combine to effect major reductions in the cost and weight of the power core equipment for the transmutation power plant. The minimum cost of electricity for such a power plant is thus reduced from the best fusion-only counterpart by more than 30%, based on consistent but approximate modeling. The key issues, development steps, and the potential value inherent in the ST fusion core in addressing the world needs for nuclear waste reduction and energy production are discussed.

  9. Evaluation of packed-bed and fluidized-bed cell technology for the destruction and removal of contaminants in alkaline waste solutions. Final report

    SciTech Connect

    Hobbs, D.T.; Bockris, J.O.M.; Kim, Jinseong

    1995-12-31

    Disposing of the large quantity of nuclear waste that has been produced within the DOE complex is an area of active research and development. Electrochemical processes have been reported for the treatment of alkaline wastes including the destruction of nitrate and nitrite and the removal of metals such as Tc and Ru. Electrolytic recovery of metals from dilute solution has been reported using conventional porous electrodes such as felt electrode and reticulated electrode, but use of such electrodes is limited. The pores of such electrodes become blocked as a consequence of metal deposition. If an attempt is made to regenerate these electrodes by dissolution of the deposited metals, oxygen evolution on the matrix competes with dissolution of metals deposited within the pores. On the other hand, the use of three dimensional packed-bed and fluidized-bed electrodes having large surface area per unit volume would offer an improvement on felt or reticulated system because of the greater ease of regeneration.

  10. Corrosion experience in calcination of liquid nuclear waste

    SciTech Connect

    Zimmerman, C A

    1980-01-01

    The Waste Calcining Facility (WCF) at the Idaho National Engineering Laboratory became operational in 1963. Since that time, approximately 13,337,137 litres (3,523,375 gallons) of liquid nuclear wastes, generated during the reprocessing of spent nuclear fuel materials, have been reduced to dry granular solids. The volume reduction is about seven or eight gallons of liquid waste to one gallon of dry granular solids. This paper covers some of the corrosion experiences encountered in over fifteen years of operating that calcination facility. 7 figures, 7 tables.

  11. Row erupts over US firm's plan to import nuclear waste

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2008-06-01

    A controversy is brewing in the US over a plan by a firm in Utah to import, process and dispose of 20 000 tonnes of low-level radioactive waste from decommissioned nuclear reactors built in Italy by American companies. EnergySolutions intends to recycle some of this waste at a site near Oak Ridge, Tennessee, so that it can be re-used as shielding blocks in nuclear plants. The firm then wants to dispose of the remaining radioactive material at a site in Clive, Utah, where over 90% of low-level radioactive waste generated in the US is currently buried.

  12. Radiation Effects in a Model Ceramic for Nuclear Waste Disposal

    SciTech Connect

    Devanathan, Ram; Weber, William J.

    2007-04-02

    The safe immobilization of nuclear waste in geological repositories is one of the major scientific challenges facing humanity today. Crystalline ceramics hold the promise of locking up actinides from nuclear fuel and excess weapons plutonium in their structure thereby isolating them from the environment. In this paper, we discuss the atomistic details of radiation damage in a model ceramic, zircon.

  13. Constructibility issues associated with a nuclear waste repository in basalt

    SciTech Connect

    Turner, D.A.

    1981-12-04

    This report contains the text and slide reproductions of a speech on nuclear waste disposal in basalt. The presentation addresses the layout of repository access shafts and subsurface facilities resulting from the conceptual design of a nuclear repository in basalt. The constructibility issues that must be resolved prior to construction are described. (DMC)

  14. Nuclear system that burns its own wastes shows promise

    NASA Technical Reports Server (NTRS)

    Atchison, K.

    1975-01-01

    A nuclear fission energy system, capable of eliminating a significant amount of its radioactive wastes by burning them, is described. A theoretical investigation of this system conducted by computer analysis, is based on use of gaseous fuel nuclear reactors. Gaseous core reactors using a uranium plasma fuel are studied along with development for space propulsion.

  15. Safety aspects of nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Edgecombe, D. S.; Compton, P. R.

    1981-01-01

    Safety issues involved in the disposal of nuclear wastes in space as a complement to mined geologic repositories are examined as part of an assessment of the feasibility of nuclear waste disposal in space. General safety guidelines for space disposal developed in the areas of radiation exposure and shielding, containment, accident environments, criticality, post-accident recovery, monitoring systems and isolation are presented for a nuclear waste disposal in space mission employing conventional space technology such as the Space Shuttle. The current reference concept under consideration by NASA and DOE is then examined in detail, with attention given to the waste source and mix, the waste form, waste processing and payload fabrication, shipping casks and ground transport vehicles, launch site operations and facilities, Shuttle-derived launch vehicle, orbit transfer vehicle, orbital operations and space destination, and the system safety aspects of the concept are discussed for each component. It is pointed out that future work remains in the development of an improved basis for the safety guidelines and the determination of the possible benefits and costs of the space disposal option for nuclear wastes.

  16. Safety aspects of nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Edgecombe, D. S.; Compton, P. R.

    1981-01-01

    Safety issues involved in the disposal of nuclear wastes in space as a complement to mined geologic repositories are examined as part of an assessment of the feasibility of nuclear waste disposal in space. General safety guidelines for space disposal developed in the areas of radiation exposure and shielding, containment, accident environments, criticality, post-accident recovery, monitoring systems and isolation are presented for a nuclear waste disposal in space mission employing conventional space technology such as the Space Shuttle. The current reference concept under consideration by NASA and DOE is then examined in detail, with attention given to the waste source and mix, the waste form, waste processing and payload fabrication, shipping casks and ground transport vehicles, launch site operations and facilities, Shuttle-derived launch vehicle, orbit transfer vehicle, orbital operations and space destination, and the system safety aspects of the concept are discussed for each component. It is pointed out that future work remains in the development of an improved basis for the safety guidelines and the determination of the possible benefits and costs of the space disposal option for nuclear wastes.

  17. Dismantlement and Radioactive Waste Management of DPRK Nuclear Facilities

    SciTech Connect

    Jooho, W.; Baldwin, G. T.

    2005-04-01

    One critical aspect of any denuclearization of the Democratic People’s Republic of Korea (DPRK) involves dismantlement of its nuclear facilities and management of their associated radioactive wastes. The decommissioning problem for its two principal operational plutonium facilities at Yongbyun, the 5MWe nuclear reactor and the Radiochemical Laboratory reprocessing facility, alone present a formidable challenge. Dismantling those facilities will create radioactive waste in addition to existing inventories of spent fuel and reprocessing wastes. Negotiations with the DPRK, such as the Six Party Talks, need to appreciate the enormous scale of the radioactive waste management problem resulting from dismantlement. The two operating plutonium facilities, along with their legacy wastes, will result in anywhere from 50 to 100 metric tons of uranium spent fuel, as much as 500,000 liters of liquid high-level waste, as well as miscellaneous high-level waste sources from the Radiochemical Laboratory. A substantial quantity of intermediate-level waste will result from disposing 600 metric tons of graphite from the reactor, an undetermined quantity of chemical decladding liquid waste from reprocessing, and hundreds of tons of contaminated concrete and metal from facility dismantlement. Various facilities for dismantlement, decontamination, waste treatment and packaging, and storage will be needed. The shipment of spent fuel and liquid high level waste out of the DPRK is also likely to be required. Nuclear facility dismantlement and radioactive waste management in the DPRK are all the more difficult because of nuclear nonproliferation constraints, including the call by the United States for “complete, verifiable and irreversible dismantlement,” or “CVID.” It is desirable to accomplish dismantlement quickly, but many aspects of the radioactive waste management cannot be achieved without careful assessment, planning and preparation, sustained commitment, and long

  18. Ethanol production from glycerol-containing biodiesel waste by Klebsiella variicola shows maximum productivity under alkaline conditions.

    PubMed

    Suzuki, Toshihiro; Nishikawa, Chiaki; Seta, Kohei; Shigeno, Toshiya; Nakajima-Kambe, Toshiaki

    2014-05-25

    Biodiesel fuel (BDF) waste contains large amounts of crude glycerol as a by-product, and has a high alkaline pH. With regard to microbial conversion of ethanol from BDF-derived glycerol, bacteria that can produce ethanol at alkaline pH have not been reported to date. Isolation of bacteria that shows maximum productivity under alkaline conditions is essential to effective production of ethanol from BDF-derived glycerol. In this study, we isolated the Klebsiella variicola TB-83 strain, which demonstrated maximum ethanol productivity at alkaline pH. Strain TB-83 showed effective usage of crude glycerol with maximum ethanol production at pH 8.0-9.0, and the culture pH was finally neutralized by formate, a by-product. In addition, the ethanol productivity of strain TB-83 under various culture conditions was investigated. Ethanol production was more efficient with the addition of yeast extract. Strain TB-83 produced 9.8 g/L ethanol (0.86 mol/mol glycerol) from cooking oil-derived BDF waste. Ethanol production from cooking oil-derived BDF waste was higher than that of new frying oil-derived BDF and pure-glycerol. This is the first report to demonstrate that the K. variicola strain TB-83 has the ability to produce ethanol from glycerol at alkaline pH.

  19. Evaluation of Waste Arising from Future Nuclear Fuel Cycle

    SciTech Connect

    Jubin, Robert Thomas; Taiwo, Temitope; Wigeland, Roald

    2015-01-01

    A comprehensive study was recently completed at the request of the US Department of Energy Office of Nuclear Energy (DOE-NE) to evaluate and screen nuclear fuel cycles. The final report was issued in October 2014. Uranium- and thorium-based fuel cycles were evaluated using both fast and thermal spectrum reactors. Once-through, limited-recycle, and continuous-recycle cases were considered. This study used nine evaluation criteria to identify promising fuel cycles. Nuclear waste management was one of the nine evaluation criteria. The waste generation criterion from this study is discussed herein.

  20. Microbial reduction of U(VI) under alkaline conditions: implications for radioactive waste geodisposal.

    PubMed

    Williamson, Adam J; Morris, Katherine; Law, Gareth T W; Rizoulis, Athanasios; Charnock, John M; Lloyd, Jonathan R

    2014-11-18

    Although there is consensus that microorganisms significantly influence uranium speciation and mobility in the subsurface under circumneutral conditions, microbiologically mediated U(VI) redox cycling under alkaline conditions relevant to the geological disposal of cementitious intermediate level radioactive waste, remains unexplored. Here, we describe microcosm experiments that investigate the biogeochemical fate of U(VI) at pH 10-10.5, using sediments from a legacy lime working site, stimulated with an added electron donor, and incubated in the presence and absence of added Fe(III) as ferrihydrite. In systems without added Fe(III), partial U(VI) reduction occurred, forming a U(IV)-bearing non-uraninite phase which underwent reoxidation in the presence of air (O2) and to some extent nitrate. By contrast, in the presence of added Fe(III), U(VI) was first removed from solution by sorption to the Fe(III) mineral, followed by bioreduction and (bio)magnetite formation coupled to formation of a complex U(IV)-bearing phase with uraninite present, which also underwent air (O2) and partial nitrate reoxidation. 16S rRNA gene pyrosequencing showed that Gram-positive bacteria affiliated with the Firmicutes and Bacteroidetes dominated in the post-reduction sediments. These data provide the first insights into uranium biogeochemistry at high pH and have significant implications for the long-term fate of uranium in geological disposal in both engineered barrier systems and the alkaline, chemically disturbed geosphere.

  1. Nuclear waste package design for the Vadose zone in tuff

    SciTech Connect

    O`Neal, W.C.; Ballou, L.B.; Gregg, D.W.; Russell, E.W.

    1984-02-01

    This report presents an overview of the selection and analysis of conceptual waste package designs that will be used by the Nevada Nuclear Waste Storage Investigations (NNWSI) project for disposal of high-level nuclear waste (HLW) at the proposed Yucca Mountain, Nevada Site. The design requirements that the waste packages are required to meet are listed. Concept drawings for the reference designs and one alternative package design are shown. Four metal alloys; 304L SS, 321 SS, 316L SS and Incoloy 825 have been selected for candidate canister/overpack materials, and 1020 carbon steel has been selected as the reference metal for the borehole liners. A summary of the results of technical and economic analysis supporting the selection of the conceptual waste package designs is included. Post-closure containment and release rates are not discussed in this paper. 17 references, 2 figures, 2 tables.

  2. Expected brine movement at potential nuclear waste repository salt sites

    SciTech Connect

    McCauley, V.S.; Raines, G.E.

    1987-08-01

    The BRINEMIG brine migration code predicts rates and quantities of brine migration to a waste package emplaced in a high-level nuclear waste repository in salt. The BRINEMIG code is an explicit time-marching finite-difference code that solves a mass balance equation and uses the Jenks equation to predict velocities of brine migration. Predictions were made for the seven potentially acceptable salt sites under consideration as locations for the first US high-level nuclear waste repository. Predicted total quantities of accumulated brine were on the order of 1 m/sup 3/ brine per waste package or less. Less brine accumulation is expected at domal salt sites because of the lower initial moisture contents relative to bedded salt sites. Less total accumulation of brine is predicted for spent fuel than for commercial high-level waste because of the lower temperatures generated by spent fuel. 11 refs., 36 figs., 29 tabs.

  3. High Resolution Sensor for Nuclear Waste Characterization

    SciTech Connect

    Shah, Kanai; Higgins, William; Van Loef, Edgar V

    2006-01-23

    Gamma ray spectrometers are an important tool in the characterization of radioactive waste. Important requirements for gamma ray spectrometers used in this application include good energy resolution, high detection efficiency, compact size, light weight, portability, and low power requirements. None of the available spectrometers satisfy all of these requirements. The goal of the Phase I research was to investigate lanthanum halide and related scintillators for nuclear waste clean-up. LaBr3:Ce remains a very promising scintillator with high light yield and fast response. CeBr3 is attractive because it is very similar to LaBr3:Ce in terms of scintillation properties and also has the advantage of much lower self-radioactivity, which may be important in some applications. CeBr3 also shows slightly higher light yield at higher temperatures than LaBr3 and may be easier to produce with high uniformity in large volume since it does not require any dopants. Among the mixed lanthanum halides, the light yield of LaBrxI3-x:Ce is lower and the difference in crystal structure of the binaries (LaBr3 and LaI3) makes it difficult to grow high quality crystals of the ternary as the iodine concentration is increased. On the other hand, LaBrxCl3-x:Ce provides excellent performance. Its light output is high and it provides fast response. The crystal structures of the two binaries (LaBr3 and LaCl3) are very similar. Overall, its scintillation properties are very similar to those for LaBr3:Ce. While the gamma-ray stopping efficiency of LaBrxCl3-x:Ce is lower than that for LaBr3:Ce (primarily because the density of LaCl3 is lower than that of LaBr3), it may be easier to grow large crystals of LaBrxCl3-x:Ce than LaBr3:Ce since in some instances (for example, CdxZn1-xTe), the ternary compounds provide increased flexibility in the crystal lattice. Among the new dopants, Eu2+ and Pr3+, tried in LaBr3 host crystals, the Eu2+ doped samples exhibited low light output. This was mostly because a

  4. Nuclear Waste: Increasing Scale and Sociopolitical Impacts

    ERIC Educational Resources Information Center

    La Porte, Todd R.

    1978-01-01

    Discusses the impact of radioactive waste management system on social and political development. The article also presents (1) types of information necessary to estimate the costs and consequences of radioactive waste management; and (2) an index of radioactive hazards to improve the basis for policy decisions. (HM)

  5. Nuclear Waste: Increasing Scale and Sociopolitical Impacts

    ERIC Educational Resources Information Center

    La Porte, Todd R.

    1978-01-01

    Discusses the impact of radioactive waste management system on social and political development. The article also presents (1) types of information necessary to estimate the costs and consequences of radioactive waste management; and (2) an index of radioactive hazards to improve the basis for policy decisions. (HM)

  6. Commercial Spent Nuclear Fuel Waste Package Misload Analysis

    SciTech Connect

    J.K. Knudson

    2003-10-02

    The purpose of this calculation is to estimate the probability of misloading a commercial spent nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or burnup) outside the waste package design. The waste package designs are based on the expected commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1 and Table 1). For this calculation, a misloaded waste package is defined as a waste package that has a fuel assembly(s) loaded into it with an enrichment and/or burnup outside the waste package design. An example of this type of misload is a fuel assembly designated for the 21-PWR Control Rod waste package being incorrectly loaded into a 21-PWR Absorber Plate waste package. This constitutes a misloaded 21-PWR Absorber Plate waste package, because the reactivity (i.e., enrichment and/or burnup) of a 21-PWR Control Rod waste package fuel assembly is outside the design of a 21-PWR Absorber Plate waste package. These types of misloads (i.e., fuel assembly with enrichment and/or burnup outside waste package design) are the only types that are evaluated in this calculation. This calculation utilizes information from ''Frequency of SNF Misload for Uncanistered Fuel Waste Package'' (CRWMS M&O 1998) as the starting point. The scope of this calculation is limited to the information available. The information is based on the whole population of fuel assemblies and the whole population of waste packages, because there is no information about the arrival of the waste stream at this time. The scope of this calculation deviates from that specified in ''Technical Work Plan for: Risk and Criticality Department'' (BSC 2002a, Section 2.1.30) in that only waste package misload is evaluated. The remaining issues identified (i.e., flooding and geometry reconfiguration) will be addressed elsewhere. The intended use of the calculation is to provide information and inputs to the Preclosure Safety Analysis

  7. Commercial Spent Nuclear Fuel Waste Package Misload Analysis

    SciTech Connect

    A. Alsaed

    2005-07-28

    The purpose of this calculation is to estimate the probability of misloading a commercial spent nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or burnup) outside the waste package design. The waste package designs are based on the expected commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1 and Table 1). For this calculation, a misloaded waste package is defined as a waste package that has a fuel assembly(s) loaded into it with an enrichment and/or burnup outside the waste package design. An example of this type of misload is a fuel assembly designated for the 21-PWR Control Rod waste package being incorrectly loaded into a 21-PWR Absorber Plate waste package. This constitutes a misloaded 21-PWR Absorber Plate waste package, because the reactivity (i.e., enrichment and/or burnup) of a 21-PWR Control Rod waste package fuel assembly is outside the design of a 21-PWR Absorber Plate waste package. These types of misloads (i.e., fuel assembly with enrichment and/or burnup outside waste package design) are the only types that are evaluated in this calculation. This calculation utilizes information from ''Frequency of SNF Misload for Uncanistered Fuel Waste Package'' (CRWMS M&O 1998) as the starting point. The scope of this calculation is limited to the information available. The information is based on the whole population of fuel assemblies and the whole population of waste packages, because there is no information about the arrival of the waste stream at this time. The scope of this calculation deviates from that specified in ''Technical Work Plan for: Risk and Criticality Department'' (BSC 2002a, Section 2.1.30) in that only waste package misload is evaluated. The remaining issues identified (i.e., flooding and geometry reconfiguration) will be addressed elsewhere. The intended use of the calculation is to provide information and inputs to the Preclosure Safety Analysis

  8. Security risks in nuclear waste management: Exceptionalism, opaqueness and vulnerability.

    PubMed

    Vander Beken, Tom; Dorn, Nicholas; Van Daele, Stijn

    2010-01-01

    This paper analyses some potential security risks, concerning terrorism or more mundane forms of crime, such as fraud, in management of nuclear waste using a PEST scan (of political, economic, social and technical issues) and some insights of criminologists on crime prevention. Nuclear waste arises as spent fuel from ongoing energy generation or other nuclear operations, operational contamination or emissions, and decommissioning of obsolescent facilities. In international and EU political contexts, nuclear waste management is a sensitive issue, regulated specifically as part of the nuclear industry as well as in terms of hazardous waste policies. The industry involves state, commercial and mixed public-private bodies. The social and cultural dimensions--risk, uncertainty, and future generations--resonate more deeply here than in any other aspect of waste management. The paper argues that certain tendencies in regulation of the industry, claimed to be justified on security grounds, are decreasing transparency and veracity of reporting, opening up invisible spaces for management frauds, and in doing allowing a culture of impunity in which more serious criminal or terrorist risks could arise. What is needed is analysis of this 'exceptional' industry in terms of the normal cannons of risk assessment - a task that this paper begins. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Volatile fatty acids production from anaerobic treatment of cassava waste water: effect of temperature and alkalinity.

    PubMed

    Hasan, Salah Din Mahmud; Giongo, Citieli; Fiorese, Mônica Lady; Gomes, Simone Damasceno; Ferrari, Tatiane Caroline; Savoldi, Tarcio Enrico

    2015-01-01

    The production of volatile fatty acids (VFAs), intermediates in the anaerobic degradation process of organic matter from waste water, was evaluated in this work. A batch reactor was used to investigate the effect of temperature, and alkalinity in the production of VFAs, from the fermentation of industrial cassava waste water. Peak production of total volatile fatty acids (TVFAs) was observed in the first two days of acidogenesis. A central composite design was performed, and the highest yield (3400 mg L(-1) of TVFA) was obtained with 30°C and 3 g L(-1) of sodium bicarbonate. The peak of VFA was in 45 h (pH 5.9) with a predominance of acetic (63%) and butyric acid (22%), followed by propionic acid (12%). Decreases in amounts of cyanide (12.9%) and chemical oxygen demand (21.6%) were observed, in addition to the production of biogas (0.53 cm(3) h(-1)). The process was validated experimentally and 3400 g L(-1) of TVFA were obtained with a low relative standard deviation.

  10. Science, Society, and America's Nuclear Waste: The Waste Management System, Unit 4. Teacher Guide. Second Edition.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

    This guide is Unit 4 of the four-part series, Science, Society, and America's Nuclear Waste, produced by the U.S. Department of Energy's Office Civilian Radioactive Waste Management. The goal of this unit is to explain how transportation, a geologic repository, and the multi-purpose canister will work together to provide short-term and long-term…

  11. Radiological characterization of the nuclear waste streams of the Belgian nuclear research centre SCK.CEN

    SciTech Connect

    Maris, Patrick; Cornelissen, Rene; Bruggeman, Michel

    2007-07-01

    The radiological characterization of nuclear wastes of a research centre is difficult seen the many different processes that generate waste. Since these wastes may contain radionuclides relevant for the disposal option, the nuclide content and activity have to be known. Considering the fact that some wastes are generated only in minor quantities, complex approaches, involving sampling and successive analysis are not justified. Basic physical models can generally be applied to estimate activity ratios, from which the radionuclide inventory can be determined by non-destructive assay on waste-packages. This article discusses waste streams at the Belgian Nuclear Research Centre SCK.CEN and explains how nuclide inventories and activity are determined. The physical models, used to derive activity ratios, and other simple approaches are discussed. (authors)

  12. The Nuclear Waste Policy Act, as amended with appropriations acts appended

    SciTech Connect

    Not Available

    1994-03-01

    The Nuclear Waste Policy Act of 1982 provides for the development of repositories for the disposal of high-level radioactive waste and spent nuclear fuel, to establish a program of research, development and demonstration regarding the disposal of high-level radioactive waste and spent nuclear fuel. Titles 1 and 2 cover these subjects. Also included in this Act are: Title 3: Other provisions relating to radioactive waste; Title 4: Nuclear waste negotiation; Title 5: Nuclear waste technical review board; and Title 6: High-level radioactive waste. An appendix contains excerpts from appropriations acts from fiscal year 1984--1994.

  13. Nuclear Magnetic Resonance Studies of Aluminosilicate Gels Prepared in High-Alkaline and Salt-Concentrated Solutions

    SciTech Connect

    Wang, Li Q.; Mattigod, Shas V.; Parker, Kent E.; Hobbs, David T.; McCready, David E.

    2005-11-01

    Solid-state 29Si, 27Al, and 23Na MAS (magic angle spinning) NMR techniques in combination with x-ray powder diffraction (XRD) are used to characterize aluminosilicate gels as a function of composition, pH, and reaction times. These gels were prepared at 80 C using initial solutions with low Si/Al ratios, high alkaline and salt concentrations that are characteristic of nuclear tank wastes. XRD data show that cancrinite and sodalite are the main crystalline phases in the aluminosilicate gels produced. It is found that the pH and the salt content have significant effects on the nature of the aluminosilicate gels. Higher pH appears to increase the rate of crystallization, the degree of overall crystallinity and the percentage of cancrinite phases in aluminosilicate gels, whereas the high salt concentration promotes the formation of cancrinite and sodalite and prohibits the formation of other zeolites. Complementary to XRD, NMR is extremely useful for providing the information on the structure of amorphous intermediate gels with no long-range order.

  14. NUCLEAR WASTE GLASSES CONTINUOUS MELTING AND BULK VITRIFICAITON

    SciTech Connect

    KRUGER AA; HRMA PR

    2008-03-24

    This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes have a variety of components and composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee the glass can be easily made and resist environmental degradation. Glass formulation is facilitated by developing property-composition models, and the strategy of model development and application is reviewed. However, the large variability of waste compositions presents numerous additional challenges: insoluble solids and molten salts may segregate; foam may hinder heat transfer and slow down the process; molten salts may accumulate in container refractory walls; the glass on cooling may precipitate crystalline phases. These problems need targeted exploratory research. Examples of specific problems and their possible solutions are discussed.

  15. National briefing summaries: Nuclear fuel cycle and waste management

    SciTech Connect

    Schneider, K.J.; Bradley, D.J.; Fletcher, J.F.; Konzek, G.J.; Lakey, L.T.; Mitchell, S.J.; Molton, P.M.; Nightingale, R.E.

    1991-04-01

    Since 1976, the International Program Support Office (IPSO) at the Pacific Northwest Laboratory (PNL) has collected and compiled publicly available information concerning foreign and international radioactive waste management programs. This National Briefing Summaries is a printout of an electronic database that has been compiled and is maintained by the IPSO staff. The database contains current information concerning the radioactive waste management programs (with supporting information on nuclear power and the nuclear fuel cycle) of most of the nations (except eastern European countries) that now have or are contemplating nuclear power, and of the multinational agencies that are active in radioactive waste management. Information in this document is included for three additional countries (China, Mexico, and USSR) compared to the prior issue. The database and this document were developed in response to needs of the US Department of Energy.

  16. Nuclear waste repository research at the micro- to nanoscale

    SciTech Connect

    Schaefer, T.; Denecke, M. A.

    2010-04-06

    Micro- and nano-focused synchrotron radiation techniques to investigate determinant processes in contaminant transport in geological media are becoming especially an increasingly used tool in nuclear waste disposal research. There are a number of reasons for this but primarily they are driven by the need to characterize actinide speciation localized in components of heterogeneous natural systems. We summarize some of the recent research conducted by researchers of the Institute of Nuclear Waste Disposal (INE) at the Karlsruhe Institute of Technology using micro- and nano-focused X-ray beams for characterization of colloids and their interaction with minerals and of elemental and phase distributions in potential repository host rocks and actinide speciation in a repository natural analogues sample. Such investigations are prerequisite to ensuring reliable assessment of the long term radiological safety for proposed nuclear waste disposal sites.

  17. Public meetings on nuclear waste management: their function and organization

    SciTech Connect

    Duvernoy, E.G.; Marcus, A.A.; Overcast, T.; Schilling, A.H.

    1981-05-01

    This report focuses on public meetings as a vehicle for public participation in nuclear waste management. The nature of public meetings is reviewed and the functions served by meetings highlighted. The range of participants and their concerns are addressed, including a review of the participants from past nuclear waste management meetings. A sound understanding of the expected participants allows DOE to tailor elements of the meeting, such as notification, format, and agenda to accommodate the attendees. Finally, the report discusses the organization of public meetings on nuclear waste management in order to enhance the DOE's functions for such meetings. Possible structures are suggested for a variety of elements that are relevant prior to, during and after the public meeting. These suggestions are intended to supplement the DOE Public Participation Manual.

  18. Disposal of slightly contaminated radioactive wastes from nuclear power plants

    SciTech Connect

    Minns, J.L.

    1995-02-01

    With regard to the disposal of solid wastes, nuclear power plants basically have two options, disposal in a Part 61 licensed low-level waste site, or receive approval pursuant to 20.2002 for disposal in a manner not otherwise authorized by the NRC. Since 1981, the staff has reviewed and approved 30 requests for disposal of slightly contaminated radioactive materials pursuant to Section 20.2002 (formerly 20.302) for nuclear power plants located in non-Agreement States. NRC Agreement States have been delegated the authority for reviewing and approving such disposals (whether onsite or offsite) for nuclear power plants within their borders. This paper describes the characteristics of the waste disposed of, the review process, and the staff`s guidelines.

  19. The role of hydrometallurgy in treating nuclear waste

    NASA Astrophysics Data System (ADS)

    Gula, Michael J.; Totura, George T.; Jassin, Lawrence

    1995-09-01

    This paper describes three case histories in which Eichrom's DiphonixTM resin was used successfully in pilot-scale equipment for the treatment of radioactive waste streams. Two of the cases describe the use of the resin for reducing actinides, primarily uranium, in an analytical waste stream and in a fuel processing effluent. The third case history reports the use of Diphonix resin to control radioactive zinc and cobalt in a nuclear power plant effluent.

  20. Chemical digestion of low level nuclear solid waste material

    DOEpatents

    Cooley, Carl R.; Lerch, Ronald E.

    1976-01-01

    A chemical digestion for treatment of low level combustible nuclear solid waste material is provided and comprises reacting the solid waste material with concentrated sulfuric acid at a temperature within the range of 230.degree.-300.degree.C and simultaneously and/or thereafter contacting the reacting mixture with concentrated nitric acid or nitrogen dioxide. In a special embodiment spent ion exchange resins are converted by this chemical digestion to noncombustible gases and a low volume noncombustible residue.

  1. Liquid level measurement in high level nuclear waste slurries

    SciTech Connect

    Weeks, G.E.; Heckendorn, F.M.; Postles, R.L.

    1990-01-01

    Accurate liquid level measurement has been a difficult problem to solve for the Defense Waste Processing Facility (DWPF). The nuclear waste sludge tends to plug or degrade most commercially available liquid-level measurement sensors. A liquid-level measurement system that meets demanding accuracy requirements for the DWPF has been developed. The system uses a pneumatic 1:1 pressure repeater as a sensor and a computerized error correction system. 2 figs.

  2. Case for retrievable high-level nuclear waste disposal

    USGS Publications Warehouse

    Roseboom, Eugene H.

    1994-01-01

    Plans for the nation's first high-level nuclear waste repository have called for permanently closing and sealing the repository soon after it is filled. However, the hydrologic environment of the proposed site at Yucca Mountain, Nevada, should allow the repository to be kept open and the waste retrievable indefinitely. This would allow direct monitoring of the repository and maintain the options for future generations to improve upon the disposal methods or use the uranium in the spent fuel as an energy resource.

  3. Differential lead retention in zircons: implications for nuclear waste containment.

    PubMed

    Gentry, R V; Sworski, T J; McKown, H S; Smith, D H; Eby, R E; Christie, W H

    1982-04-16

    An innovative ultrasensitive technique was used for lead isotopic analysis of individual zircons extracted from granite core samples at depths of 960, 2170, 2900, 3930, and 4310 meters. The results show that lead, a relatively mobile element compared to the nuclear waste-related actinides uranium and thorium, has been highly retained at elevated temperatures (105 degrees to 313 degrees C) under conditions relevant to the burial of synthetic rock waste containers in deep granite holes.

  4. Deep Geologic Nuclear Waste Disposal - No New Taxes - 12469

    SciTech Connect

    Conca, James; Wright, Judith

    2012-07-01

    To some, the perceived inability of the United States to dispose of high-level nuclear waste justifies a moratorium on expansion of nuclear power in this country. Instead, it is more an example of how science yields to social pressure, even on a subject as technical as nuclear waste. Most of the problems, however, stem from confusion on the part of the public and their elected officials, not from a lack of scientific knowledge. We know where to put nuclear waste, how to put it there, how much it will cost, and how well it will work. And it's all about the geology. The President's Blue Ribbon Commission on America's Nuclear Future has drafted a number of recommendations addressing nuclear energy and waste issues (BRC 2011) and three recommendations, in particular, have set the stage for a new strategy to dispose of high-level nuclear waste and to manage spent nuclear fuel in the United States: 1) interim storage for spent nuclear fuel, 2) resumption of the site selection process for a second repository, and 3) a quasi-government entity to execute the program and take control of the Nuclear Waste Fund in order to do so. The first two recommendations allow removal and storage of spent fuel from reactor sites to be used in the future, and allows permanent disposal of actual waste, while the third controls cost and administration. The Nuclear Waste Policy Act of 1982 (NPWA 1982) provides the second repository different waste criteria, retrievability, and schedule, so massive salt returns as the candidate formation of choice. The cost (in 2007 dollars) of disposing of 83,000 metric tons of heavy metal (MTHM) high-level waste (HLW) is about $ 83 billion (b) in volcanic tuff, $ 29 b in massive salt, and $ 77 b in crystalline rock. Only in salt is the annual revenue stream from the Nuclear Waste Fund more than sufficient to accomplish this program without additional taxes or rate hikes. The cost is determined primarily by the suitability of the geologic formation, i.e., how

  5. Enhancement of thermophilic anaerobic digestion of thickened waste activated sludge by combined microwave and alkaline pretreatment.

    PubMed

    Chi, Yongzhi; Li, Yuyou; Fei, Xuening; Wang, Shaopo; Yuan, Hongying

    2011-01-01

    Abstract Pretreatment of thickened waste activated sludge (TWAS) by combined microwave and alkaline pretreatment (MAP) was studied to improve thermophilic anaerobic digestion efficiency. Uniform design was applied to determine the combination of target temperature (11 degrees-210 degrees C), microwave holding time (1-51 min), and NaOH dose (0-2.5 g NaOH/g suspended solids (SS)) in terms of their effect on volatile suspended solids (VSS) solubilization. Maximum solubilization ratio (85.1%) of VSS was observed at 210 degrees C with 0.2 g-NaOH/g-SS and 35 min holding time. The effects of 12 different pretreatment methods were investigated in 28 thermophilic batch reactors by monitoring cumulative methane production (CMP). Improvements in methane production in the TWAS were directly related to the microwave and alkaline pretreatment of the sludge. The highest CMP was a 27% improvement over the control. In spite of the increase in soluble chemical oxygen demand concentration and the decrease in dewaterability of digested sludge, a semi-continuous thermophilic reactor fed with pretreated TWAS without neutralization (at 170 degrees C with 1 min holding time and 0.05 g NaOH/g SS) was stable and functioned well, with volatile solid (VS) and total chemical oxygen demand (TCOD) reductions of 28% and 18%, respectively, which were higher than those of the control system. Additionally, methane yields (L@STP/g-CODadded, at standard temperature and pressure (STP) conditions of 0 degree C and 101.325 kPa) and (L@STP/g VSadded) increased by 17% and 13%, respectively, compared to the control reactor.

  6. Use of natural mordenite to remove chromium (III) and to neutralize pH of alkaline waste waters.

    PubMed

    Córdova-Rodríguez, Valduvina; Rodríguez-Iznaga, Inocente; Acosta-Chávez, Raquel María; Chávez-Rivas, Fernando; Petranovskii, Vitalii; Pestryakov, Alexey

    2016-01-01

    The natural mordenite from Palmarito de Cauto deposit (PZ), Cuba, was studied in this work as an ion exchanger to remove Cr(3+) cations from alkaline aqueous solutions at different pH and chromium concentrations. The mordenite stability under cyclic treatment processes with alkaline solutions and its capacity to decrease the pH of the solutions was also analyzed. It was shown that PZ removes Cr(3+) ions from alkaline solutions, and it happens independently of the starting chromium concentration and the pH of the exchange solution used. This material has an important neutralizing effect on alkaline solutions, expressed in a significant pH decrease from the early stages of the treatments. For solutions with initial pH equal to 11, it decreases to a value of around seven. The stability of this material is not affected significantly after continuous cyclic treatment with NaOH solution, which shows that mordenite, in particular from Palmarito de Cauto deposit, has high stability in alkaline solutions. The results are important as they suggest that natural zeolites may be of interest in treatments of alkaline industrial waste effluents.

  7. Improved methane production from waste activated sludge with low organic content by alkaline pretreatment at pH 10.

    PubMed

    Feng, L Y; Yang, L Q; Zhang, L X; Chen, H L; Chen, J

    2013-01-01

    Sludge with low organic content always results in an unsatisfactory performance, even failure of anaerobic digestion. The alkaline pretreatment effect on anaerobic digestion of sludge with low organic content has seldom been studied although it gives many benefits for sludge with high organic content. In this study the influence of alkaline pretreatment (pH 10, an effective alkaline pH) on the solubilization and methane production from waste activated sludge (WAS) with low organic content was investigated. Results from biochemical methane potential (BMP) experiments showed that anaerobic biodegradability of WAS was greatly improved by alkaline pretreatment at pH 10. Methane production from the current WAS under conditions of pretreatment time 4 h and digestion time 15 d was 139.6 mL/g VS (volatile solids), much higher than that from the unpretreated WAS with digestion time of 20 d (75.2 mL/g VS). Also, the solubilization of WAS was significantly accelerated by alkaline pretreatment. Mechanism exploration indicated that the general activities of anaerobic microorganisms, specific activities of key enzymes and the amounts of methanogens were enhanced by alkaline pretreatment at pH 10, showing good agreement with methane production.

  8. Nuclear Methods for Transmutation of Nuclear Waste: Problems, Perspextives, Cooperative Research - Proceedings of the International Workshop

    NASA Astrophysics Data System (ADS)

    Khankhasayev, Zhanat B.; Kurmanov, Hans; Plendl, Mikhail Kh.

    1996-12-01

    The Table of Contents for the full book PDF is as follows: * Preface * I. Review of Current Status of Nuclear Transmutation Projects * Accelerator-Driven Systems — Survey of the Research Programs in the World * The Los Alamos Accelerator-Driven Transmutation of Nuclear Waste Concept * Nuclear Waste Transmutation Program in the Czech Republic * Tentative Results of the ISTC Supported Study of the ADTT Plutonium Disposition * Recent Neutron Physics Investigations for the Back End of the Nuclear Fuel Cycle * Optimisation of Accelerator Systems for Transmutation of Nuclear Waste * Proton Linac of the Moscow Meson Factory for the ADTT Experiments * II. Computer Modeling of Nuclear Waste Transmutation Methods and Systems * Transmutation of Minor Actinides in Different Nuclear Facilities * Monte Carlo Modeling of Electro-nuclear Processes with Nonlinear Effects * Simulation of Hybrid Systems with a GEANT Based Program * Computer Study of 90Sr and 137Cs Transmutation by Proton Beam * Methods and Computer Codes for Burn-Up and Fast Transients Calculations in Subcritical Systems with External Sources * New Model of Calculation of Fission Product Yields for the ADTT Problem * Monte Carlo Simulation of Accelerator-Reactor Systems * III. Data Basis for Transmutation of Actinides and Fission Products * Nuclear Data in the Accelerator Driven Transmutation Problem * Nuclear Data to Study Radiation Damage, Activation, and Transmutation of Materials Irradiated by Particles of Intermediate and High Energies * Radium Institute Investigations on the Intermediate Energy Nuclear Data on Hybrid Nuclear Technologies * Nuclear Data Requirements in Intermediate Energy Range for Improvement of Calculations of ADTT Target Processes * IV. Experimental Studies and Projects * ADTT Experiments at the Los Alamos Neutron Science Center * Neutron Multiplicity Distributions for GeV Proton Induced Spallation Reactions on Thin and Thick Targets of Pb and U * Solid State Nuclear Track Detector and

  9. Preclosure analysis of conceptual waste package designs for a nuclear waste repository in tuff

    SciTech Connect

    O`Neal, W.C.; Gregg, D.W.; Hockman, J.N.; Russell, E.W.; Stein, W.

    1984-11-01

    This report discusses the selection and analysis of conceptual waste package developed by the Nevada Nuclear Waste Storage Investigations (NNWSI) project for possible disposal of high-level nuclear waste at a candidate site at Yucca Mountain, Nevada. The design requirements that the waste package must conform to are listed, as are several desirable design considerations. Illustrations of the reference and alternative designs are shown. Four austenitic stainless steels (316L SS, 321 SS, 304L SS and Incoloy 825 high nickel alloy) have been selected for candidate canister/overpack materials, and 1020 carbon steel has been selected as the reference metal for the borehole liners. A summary of the results of technical and ecnonmic analyses supporting the selection of the conceptual waste package designs is included. Postclosure containment and release rates are not analyzed in this report.

  10. Recovery of transplutonium elements from nuclear reactor waste

    DOEpatents

    Campbell, David O.; Buxton, Samuel R.

    1977-05-24

    A method of separating actinide values from nitric acid waste solutions resulting from reprocessing of irradiated nuclear fuels comprises oxalate precipitation of the major portion of actinide and lanthanide values to provide a trivalent fraction suitable for subsequent actinide/lanthanide partition, exchange of actinide and lanthanide values in the supernate onto a suitable cation exchange resin to provide an intermediate-lived raffinate waste stream substantially free of actinides, and elution of the actinide values from the exchange resin. The eluate is then used to dissolve the trivalent oxalate fraction prior to actinide/lanthanide partition or may be combined with the reprocessing waste stream and recycled.

  11. Process to separate transuranic elements from nuclear waste

    DOEpatents

    Johnson, T.R.; Ackerman, J.P.; Tomczuk, Z.; Fischer, D.F.

    1988-07-12

    A process for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR). 2 figs.

  12. Process to separate transuranic elements from nuclear waste

    DOEpatents

    Johnson, T.R.; Ackerman, J.P.; Tomczuk, Z.; Fischer, D.F.

    1989-03-21

    A process is described for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR). 2 figs.

  13. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs, D

    2008-01-22

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90 and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction, for Cs-137 removal. The MST and separated Cs-137 will be encapsulated into a borosilicate glass waste form for eventual entombment at the federal repository. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239 and Pu-240. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.

  14. Disposition of salt-waste from pyrochemical nuclear fuel processing

    SciTech Connect

    Vance, E.R.

    2007-07-01

    Waste salts from pyrochemical processing of nuclear fuel can be immobilised in sodalite if consolidated by hot isostatic pressing (HIP) at {approx}750 deg. C/100 MPa in thick stainless steel 316 cans. Other canning materials for this purpose also look possible. Spodiosite-based waste forms do not look promising in terms of leach resistance and their incorporation of alkali ions and compatibility with other phases which could potentially accommodate fission products, such as NaZr{sub 2}(PO{sub 4}){sub 3} or alumino-phosphate glass. Chloro- or fluor-apatite-based waste forms however have been reported to successfully accommodate fission products and alkalis which would be derived from either chloride- or fluoride-based waste pyro-processing salts. The presence of 10 or 20 wt% of additional Whitlockite, Ca{sub 3}(PO{sub 4}){sub 2}, should allow chemical flexibility to maintain the same qualitative phase assemblage when there are variations in the waste feed and in the waste/precursor ratios. Experimental verification of incorporation of the full complement of waste salts and fission products is not yet complete however. Apatite-rich samples could likely be HIPed in Inconel 600 cans. Other candidate HIP canning materials such as Alloy 22 or Inconel 625 are under study by encapsulating them in the candidate waste form and studying their interaction or otherwise with the waste form. (author)

  15. Nuclear waste management. Quarterly progress report, January-March, 1981

    SciTech Connect

    Chikalla, T.D.; Powell, J.A.

    1981-06-01

    Reports and summaries are provided for the following programs: high-level waste process development; alternative waste forms; nuclear waste materials characterization center; TRU waste immobilization; TRU waste decontamination; krypton solidification; thermal outgassing; iodine-129 fixation; NWVP off-gas analysis; monitoring and physical characterization of unsaturated zone transport; well-logging instrumentation development; verification instrument development; mobility of organic complexes of radionuclide in soils; low-level waste generation reduction handbook; waste management system studies; assessment of effectiveness of geologic isolation systems; waste/rock interactions technology program; high-level waste form preparation; development of backfill materials; development of structural engineered barriers; disposal charge analysis; analysis of spent fuel policy implementation; spent fuel and pool component integrity program; analysis of postulated criticality events in a storage array of spent LWR fuel; asphalt emulsion sealing of uranium mill tailings; liner evaluation for uranium mill tailings; multilayer barriers for sealing of uranium tailings; application of long-term chemical biobarriers for uranium tailings; and revegetation of inactive uranium tailings sites.

  16. Thermal investigation of nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Wilkinson, C. L.

    1981-01-01

    A thermal analysis has been conducted to determine the allowable size and response of bare and shielded nuclear waste forms in both low earth orbit and at 0.85 astronomical units. Contingency conditions of re-entry with a 45 deg and 60 deg aeroshell are examined as well as re-entry of a spherical shielded waste form. A variety of shielded schemes were examined and the waste form thermal response for each determined. Two optimum configurations were selected. The thermal response of these two shielded waste configurations to indefinite exposure to ground conditions following controlled and uncontrolled re-entry is determined. In all cases the prime criterion is that waste containment must be maintained.

  17. Thermal investigation of nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Wilkinson, C. L.

    1981-01-01

    A thermal analysis has been conducted to determine the allowable size and response of bare and shielded nuclear waste forms in both low earth orbit and at 0.85 astronomical units. Contingency conditions of re-entry with a 45 deg and 60 deg aeroshell are examined as well as re-entry of a spherical shielded waste form. A variety of shielded schemes were examined and the waste form thermal response for each determined. Two optimum configurations were selected. The thermal response of these two shielded waste configurations to indefinite exposure to ground conditions following controlled and uncontrolled re-entry is determined. In all cases the prime criterion is that waste containment must be maintained.

  18. Mesoscale to plant-scale models of nuclear waste reprocessing.

    SciTech Connect

    Noble, David Frederick; O'Hern, Timothy John; Moffat, Harry K.; Nemer, Martin B.; Domino, Stefan Paul; Rao, Rekha Ranjana; Cipiti, Benjamin B.; Brotherton, Christopher M.; Jove-Colon, Carlos F.; Pawlowski, Roger Patrick

    2010-09-01

    Imported oil exacerabates our trade deficit and funds anti-American regimes. Nuclear Energy (NE) is a demonstrated technology with high efficiency. NE's two biggest political detriments are possible accidents and nuclear waste disposal. For NE policy, proliferation is the biggest obstacle. Nuclear waste can be reduced through reprocessing, where fuel rods are separated into various streams, some of which can be reused in reactors. Current process developed in the 1950s is dirty and expensive, U/Pu separation is the most critical. Fuel rods are sheared and dissolved in acid to extract fissile material in a centrifugal contactor. Plants have many contacts in series with other separations. We have taken a science and simulation-based approach to develop a modern reprocessing plant. Models of reprocessing plants are needed to support nuclear materials accountancy, nonproliferation, plant design, and plant scale-up.

  19. Review and evaluation of metallic TRU nuclear waste consolidation methods

    SciTech Connect

    Montgomery, D.R.; Nesbitt, J.F.

    1983-08-01

    The US Department of Energy established the Commercial Waste Treatment Program to develop, demonstrate, and deploy waste treatment technology. In this report, viable methods are identified that could consolidate the volume of metallic wastes generated in a fuel reprocessing facility. The purpose of this study is to identify, evaluate, and rate processes that have been or could be used to reduce the volume of contaminated/irradiated metallic waste streams and to produce an acceptable waste form in a safe and cost-effective process. A technical comparative evaluation of various consolidation processes was conducted, and these processes were rated as to the feasibility and cost of producing a viable product from a remotely operated radioactive process facility. Out of the wide variety of melting concepts and consolidation systems that might be applicable for consolidating metallic nuclear wastes, the following processes were selected for evaluation: inductoslay melting, rotating nonconsumable electrode melting, plasma arc melting, electroslag melting with two nonconsumable electrodes, vacuum coreless induction melting, and cold compaction. Each process was evaluated and rated on the criteria of complexity of process, state and type of development required, safety, process requirements, and facility requirements. It was concluded that the vacuum coreless induction melting process is the most viable process to consolidate nuclear metallic wastes. 11 references.

  20. Chemistry of pyroprocessing for nuclear waste transmutation

    SciTech Connect

    Ackerman, J.P.

    1995-10-01

    Pyrochemical treatment of spent nuclear fuel is an attractive approach for separating the transuranium (TRU) elements neptunium, plutonium, americium, and curium because of its simplicity, diversion resistance, and potentially low cost.

  1. Risk analysis and solving the nuclear waste siting problem

    SciTech Connect

    Inhaber, H.

    1993-12-01

    In spite of millions of dollars and countless human resources being expended on finding nuclear wastes sites, the search has proved extremely difficult for the nuclear industry. This may be due to the approach followed, rather than inadequacies in research or funding. A new approach to the problem, the reverse Dutch auction, is suggested. It retains some of the useful elements of the present system, but it also adds new ones.

  2. International High Level Nuclear Waste Management

    ERIC Educational Resources Information Center

    Dreschhoff, Gisela; And Others

    1974-01-01

    Discusses the radioactive waste management in Belgium, Canada, France, Germany, India, Italy, Japan, the United Kingdom, the United States, and the USSR. Indicates that scientists and statesmen should look beyond their own lifetimes into future centuries and millennia to conduct long-range plans essential to protection of future generations. (CC)

  3. Siting Patterns of Nuclear Waste Repositories.

    ERIC Educational Resources Information Center

    Solomon, Barry D.; Shelley, Fred M.

    1988-01-01

    Provides an inventory of international radioactive waste-management policies and repository siting decisions for North America, Central and South America, Europe, Asia, and Africa. This discussion stresses the important role of demographic, geologic, and political factors in siting decisions. (Author/BSR)

  4. International High Level Nuclear Waste Management

    ERIC Educational Resources Information Center

    Dreschhoff, Gisela; And Others

    1974-01-01

    Discusses the radioactive waste management in Belgium, Canada, France, Germany, India, Italy, Japan, the United Kingdom, the United States, and the USSR. Indicates that scientists and statesmen should look beyond their own lifetimes into future centuries and millennia to conduct long-range plans essential to protection of future generations. (CC)

  5. Siting Patterns of Nuclear Waste Repositories.

    ERIC Educational Resources Information Center

    Solomon, Barry D.; Shelley, Fred M.

    1988-01-01

    Provides an inventory of international radioactive waste-management policies and repository siting decisions for North America, Central and South America, Europe, Asia, and Africa. This discussion stresses the important role of demographic, geologic, and political factors in siting decisions. (Author/BSR)

  6. Salt disposal of heat-generating nuclear waste.

    SciTech Connect

    Leigh, Christi D.; Hansen, Francis D.

    2011-01-01

    This report summarizes the state of salt repository science, reviews many of the technical issues pertaining to disposal of heat-generating nuclear waste in salt, and proposes several avenues for future science-based activities to further the technical basis for disposal in salt. There are extensive salt formations in the forty-eight contiguous states, and many of them may be worthy of consideration for nuclear waste disposal. The United States has extensive experience in salt repository sciences, including an operating facility for disposal of transuranic wastes. The scientific background for salt disposal including laboratory and field tests at ambient and elevated temperature, principles of salt behavior, potential for fracture damage and its mitigation, seal systems, chemical conditions, advanced modeling capabilities and near-future developments, performance assessment processes, and international collaboration are all discussed. The discussion of salt disposal issues is brought current, including a summary of recent international workshops dedicated to high-level waste disposal in salt. Lessons learned from Sandia National Laboratories' experience on the Waste Isolation Pilot Plant and the Yucca Mountain Project as well as related salt experience with the Strategic Petroleum Reserve are applied in this assessment. Disposal of heat-generating nuclear waste in a suitable salt formation is attractive because the material is essentially impermeable, self-sealing, and thermally conductive. Conditions are chemically beneficial, and a significant experience base exists in understanding this environment. Within the period of institutional control, overburden pressure will seal fractures and provide a repository setting that limits radionuclide movement. A salt repository could potentially achieve total containment, with no releases to the environment in undisturbed scenarios for as long as the region is geologically stable. Much of the experience gained from United

  7. Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms

    SciTech Connect

    Weber, William J.; Zhang, Yanwen

    2016-09-20

    This is the final report of the NEUP project “Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms.” This project started on July 1, 2012 and was successfully completed on June 30, 2016. This report provides an overview of the main achievements, results and findings through the duration of the project. Additional details can be found in the main body of this report and in the individual Quarterly Reports and associated Deliverables of this project, which have been uploaded in PICS-NE. The objective of this research was to advance understanding and develop validated models on the effects of self-radiation from beta and alpha decay on the response of used nuclear fuel and nuclear waste forms during high-temperature interim storage and long-term permanent disposition. To achieve this objective, model used-fuel materials and model waste form materials were identified, fabricated, and studied.

  8. Development of glass vitrification at SRL as a waste treatment technique for nuclear weapon components

    SciTech Connect

    Coleman, J.T.; Bickford, D.F.

    1991-12-31

    This report discusses the development of vitrification for the waste treatment of nuclear weapons components at the Savannah River Site. Preliminary testing of surrogate nuclear weapon electronic waste shows that glass vitrification is a viable, robust treatment method.

  9. Development of glass vitrification at SRL as a waste treatment technique for nuclear weapon components

    SciTech Connect

    Coleman, J.T.; Bickford, D.F.

    1991-01-01

    This report discusses the development of vitrification for the waste treatment of nuclear weapons components at the Savannah River Site. Preliminary testing of surrogate nuclear weapon electronic waste shows that glass vitrification is a viable, robust treatment method.

  10. Radiation effects in nuclear waste materials. 1998 annual progress report

    SciTech Connect

    Weber, W.J.; Corrales, L.R.; Birtcher, R.C.; Nastasi, M.

    1998-06-01

    'The objective of this multidisciplinary, multi-institutional research effort is to develop a fundamental understanding of radiation effects in glasses and ceramics at the atomic, microscopic, and macroscopic levels. The goal is to provide the underpinning science and models necessary to assess the performance of glasses and ceramics designed for the immobilization and disposal of high-level tank waste, plutonium residues, excess weapons plutonium, and other highly radioactive waste streams. A variety of experimental and computer simulation methods are employed in this effort. In general, research on glasses focuses on the electronic excitations due to ionizing radiation emitted from beta decay, since this is currently thought to be the principal mechanism for deleterious radiation effects in nuclear waste glasses. Research on ceramics focuses on defects and structural changes induced by the elastic interactions between alpha-decay particles and the atoms in the structure. Radiation effects can lead to changes in physical and chemical properties that may significantly impact long-term performance of nuclear waste materials. The current lack of fundamental understanding of radiation effects in nuclear waste materials makes it impossible to extrapolate the limited existing data bases to larger doses, lower dose rates, different temperature regimes, and different glass compositions or ceramic structures. This report summarizes work after almost 2 years of a 3-year project. Work to date has resulted in 9 publications. Highlights of the research over the past year are presented.'

  11. Effect of thermal alkaline pretreatment on the anaerobic digestion of wasted activated sludge.

    PubMed

    Vigueras-Carmona, S E; Ramírez, F; Noyola, A; Monroy, O

    2011-01-01

    The effect of alkaline pretreatment of waste-activated sludge, using two models to study the sequential hydrolysis rates of suspended (Sanders' surface model) and dissolved (Goel's saturation model) solids, on the mesophilic and thermophilic anaerobic digestion rate is evaluated. The pretreatment, which reduces the size of the solids, increases the reaction rate by increasing the surface area and the specific surface hydrolysis constant (K(SBK)); at thermophilic conditions from 0.45 x 10(-3) kg m(-2) d(-1) for the fresh sludge to 0.74 x 10(-3) kg m(-2) d(-1) for the pretreated sludge and at mesophilic conditions these values are 0.28 x 10(-3) kg m(-2) d(-1) and 0.47 x 10(-3) kg m(-2) d(-1) confirming the usefulness of a pretreatment for solids reduction. But for soluble solids, the thermoalkaline pretreatment decreases the reaction rates by inducing a competitive inhibition on the thermophilic anaerobic digestion rate while in the mesophilic range, a non-competitive inhibition is observed. A mathematical simulation of the consecutive reactions, suspended solids to dissolved solids and to methane in staged anaerobic thermophilic-mesophilic digestion, shows that with 4% suspended solids concentration it is better not to use a thermoalkaline pretreatment because overall solids reduction and total methane production are not as good as without pretreatment.

  12. Managing nuclear waste: Social and economic impacts

    SciTech Connect

    Hemphill, R.C.; Bassett, G.W. Jr.

    1993-03-01

    Recent research has focused on perceptions of risk dominant source of economic impacts due to siting a high level radioactive waste facility. This article addresses the social and economic considerations involved with the issue of risk perception and other types of negative imagery. Emphasis is placed on ways of measuring the potential for economic effects resulting from perceptions prior to construction and operation of a HLW facility. We describe the problems in arriving at defensible estimates of economic impacts. Our review has found that although legal and regulatory bases may soon allow inclusion of these impacts in EIS and for compensation purposes, credible scientific methods do not currently exist for predicting the existence or magnitude of changes in economic decision-making. Policy-makers should recognize the potential for perception-based economic impacts in determining the location and means of managing radioactive waste; but, they also need be cognizant of the current limitations of quantitative estimates of impacts in this area.

  13. AIROX nuclear fuel recycling and waste management

    SciTech Connect

    Thomas, T.R.

    1993-06-01

    This report discusses the AIROX process which is a dry pyrochemical process developed by Atomic International for recycling LWR spent fuels which would retain most of the fission-product inventory in reconstituted fuel assemblies. The process would: (1) avoid the generation of high-level liquid waste streams, (2) recycle fertile U-238, unburned U-235, and unburned transuranics, and, (3) in principle, allow extended burnup to about 120 MWd/kg via three or four recycles. In this study: (1) prior AIROX studies were reviewed, (2) a preconceptual design and cost estimate of an AIROX plant were developed, (3) types and amounts of wastes that would be generated were calculated, and (4) further R&D needs for the AIROX process were identified.

  14. Backfill composition for secondary barriers in nuclear waste repositories

    DOEpatents

    Beall, G.W.; Allard, B.M.

    1980-05-30

    A backfill composition for sorbing and retaining hazardous elements of nuclear wastes comprises 50 to 70% by weight of quartz, 10 to 30% by weight of montmorillonite, 1 to 10% by weight of phosphate mineral, 1 to 10% by weight of ferrous mineral, 1 to 10% by weight of sulfate mineral and 1 to 10% by weight of attapulgite.

  15. Hazards of managing and disposing of nuclear waste

    SciTech Connect

    Kastenberg, W.E.; Gratton, L.J.

    1997-06-01

    When we bury long-lived nuclear wastes in geologic repositories, we have to worry about what may happen ten thousand{emdash}or even a million{emdash}years in the future.{copyright} {ital 1997 American Institute of Physics.}

  16. Backfill composition for secondary barriers in nuclear waste repositories

    DOEpatents

    Beall, Gary W.; Allard, Bert M.

    1982-01-01

    A backfill composition for sorbing and retaining hazardous elements of nuclear wastes comprises 50-70% by weight of quartz, 10-30% by weight of montmorillonite, 1-10% by weight of phosphate mineral, 1-10% by weight of ferrous mineral, 1-10% by weight of sulfate mineral and 1-10% by weight of attapulgite.

  17. Nuclear Waste Disposal: Can Government Cope?

    DTIC Science & Technology

    1983-12-01

    Codes December 1983Avlardo Dist Special The original version of this study was prepared by the author, Jackie L. Braitman, as a dissertation in partial...disposal, are to be met. The work originates from a supposition that the failure, thus far, S S of the Department of Energy (DOE) to site and develop...develop the capabilities needed to site a high-level radioactive waste repository. Lester Salamon (1981) advances a similar question in his critique of

  18. Evaluation of the transport and resuspension of a simulated nuclear waste slurry: Nuclear Waste Treatment Program

    SciTech Connect

    Carleson, T.E.; Drown, D.C.; Hart, R.E.; Peterson, M.E.

    1987-09-01

    The Department of Chemical Engineering at the University of Idaho conducted research on the transport and resuspension of a simulated high-level nuclear waste slurry. In the United States, the reference process for treating both defense and civilian HLLW is vitrification using the liquid-fed ceramic melter process. The non-Newtonian behavior of the slurry complicates the evaluation of the transport and resuspension characteristics of the slurry. The resuspension of a simulated (nonradioactive) melter feed slurry was evaluated using a slurry designated as WV-205. The simulated slurry was developed for the West Valley Demonstration Project and was used during a pilot-scale ceramic melter (PSCM) experiment conducted at PNL in July 1985 (PSCM-21). This study involved determining the transport characteristics of a fully suspended slurry and the resuspension characteristics of settled solids in a pilot-scale pipe loop. The goal was to predict the transport and resuspension of a full-scale system based on rheological data for a specific slurry. The rheological behavior of the slurry was evaluated using a concentric cylinder rotational viscometer, a capillary tube viscometer, and the pilot-scale pipe loop. The results obtained from the three approaches were compared. 40 refs., 74 figs., 15 tabs.

  19. Improved Performance of the Alkaline-Side CSEX Process for Cesium Extraction from Alkaline High-Level Waste Obtained by Characterization of the Effect of Surfactant Impurities

    SciTech Connect

    Delmau, L.H.

    1999-11-04

    Improved understanding and performance of the alkaline-side CSEX process has been obtained through the characterization of impurity effects that hinder complete stripping of cesium from the solvent. It is shown in this report that tests of the alkaline-side CSEX process conducted in the summer and fall of 1998 were complicated by the presence of common surfactant anions, undecyl- and dodecylsulfonate, as trace impurities in the two simulants tested. This conclusion was drawn from the results of a series of systematic extraction tests followed by a definitive identification by electrospray mass spectrometry (ES-MS). Based on this understanding, a straightforward preventative measure involving the addition of a lipophilic tertiary amine extractant at a small concentration to the solvent is proposed and demonstrated. As part of the task ''Fission Product Solvent Extraction'' supported by the Efficient Separations and Processing Crosscutting Program within the USDOE Office of Environmental Management, the alkaline-side CSEX process has been developed for removal of radio-cesium ({sup 137}Cs) from alkaline high-level wastes stored in underground tanks at the Hanford Site and Savannah River Site (SRS). As described in a previous report, tests conducted in Fiscal Year 1998 generally demonstrated performance meeting the requirements for cesium removal from the waste to be treated at the SRS. However, discrepancies in stripping behavior were shown to arise from unidentified differences ''in the batches of waste simulant employed for testing. Various effects such as solvent impurities, kinetics, contacting method, and counting method were eliminated as possible causes of the observed discrepancies. Tests in Fiscal Year 1999 reported herein confirmed the earlier suspicion that the simulants contained lipophilic anionic impurities. Extraction tests demonstrated that the impurities could be concentrated in the solvent, and by ES-MS in the negative-ion mode it was possible to

  20. Waste Minimization Policy at the Romanian Nuclear Power Plant

    SciTech Connect

    Andrei, V.; Daian, I.

    2002-02-26

    The radioactive waste management system at Cernavoda Nuclear Power Plant (NPP) in Romania was designed to maintain acceptable levels of safety for workers and to protect human health and the environment from exposure to unacceptable levels of radiation. In accordance with terminology of the International Atomic Energy Agency (IAEA), this system consists of the ''pretreatment'' of solid and organic liquid radioactive waste, which may include part or all of the following activities: collection, handling, volume reduction (by an in-drum compactor, if appropriate), and storage. Gaseous and aqueous liquid wastes are managed according to the ''dilute and discharge'' strategy. Taking into account the fact that treatment/conditioning and disposal technologies are still not established, waste minimization at the source is a priority environmental management objective, while waste minimization at the disposal stage is presently just a theoretical requirement for future adopted technologies . The necessary operational and maintenance procedures are in place at Cernavoda to minimize the production and contamination of waste. Administrative and technical measures are established to minimize waste volumes. Thus, an annual environmental target of a maximum 30 m3 of radioactive waste volume arising from operation and maintenance has been established. Within the first five years of operations at Cernavoda NPP, this target has been met. The successful implementation of the waste minimization policy has been accompanied by a cost reduction while the occupational doses for plant workers have been maintained at as low as reasonably practicable levels. This paper will describe key features of the waste management system along with the actual experience that has been realized with respect to minimizing the waste volumes at the Cernavoda NPP.

  1. Nuclear-waste disposal: Technical issues and status

    NASA Astrophysics Data System (ADS)

    Hunter, T. O.

    The nuclear waste from the defense programs of the United States and the commercial nuclear fuel cycle are planned for disposal in mined geologic repositories. High-level waste will require the development of one to three repositories. A number of technical issues are associated with the selection and characterization of a suitable site, the design of surface and underground facilities, development of an appropriate waste package, and methods to assess the performance of the system relative to regulatory requirements. These issues are being addressed by four major projects to evaluate salt, basalt, volcanic tuff, and other crystalline rocks such as granite. The key technical issues and the status of activities to resolve those issues are reviewed.

  2. Conceptual Model of Uranium in the Vadose Zone for Acidic and Alkaline Wastes Discharged at the Hanford Site Central Plateau

    SciTech Connect

    Truex, Michael J.; Szecsody, James E.; Qafoku, Nikolla; Serne, R. Jeffrey

    2014-09-01

    Historically, uranium was disposed in waste solutions of varying waste chemistry at the Hanford Site Central Plateau. The character of how uranium was distributed in the vadose zone during disposal, how it has continued to migrate through the vadose zone, and the magnitude of potential impacts on groundwater are strongly influenced by geochemical reactions in the vadose zone. These geochemical reactions can be significantly influenced by the disposed-waste chemistry near the disposal location. This report provides conceptual models and supporting information to describe uranium fate and transport in the vadose zone for both acidic and alkaline wastes discharged at a substantial number of waste sites in the Hanford Site Central Plateau. The conceptual models include consideration of how co-disposed acidic or alkaline fluids influence uranium mobility in terms of induced dissolution/precipitation reactions and changes in uranium sorption with a focus on the conditions near the disposal site. This information, when combined with the extensive information describing uranium fate and transport at near background pH conditions, enables focused characterization to support effective fate and transport estimates for uranium in the subsurface.

  3. Long-term nuclear waste management: Present status and alternatives

    NASA Astrophysics Data System (ADS)

    Schapira, J. P.

    1989-08-01

    Long-term nuclear waste management deals with the final and irreversible stage of waste disposal, on surface and in deep geological formations (according to the waste type), when institutional surveillance is over. There are presently two main options available to deal with the wastes generated by spent nuclear fuel unloaded from reactors and containing most of the radiotoxicity produced all along the nuclear fuel cycle. Since the end of Word War II, spent-fuel reprocessing technology has gone through three different stages, ending up with considerable technical achievements and large investments (construction of large facilities, UP3 in France and THORP in the UK). However, having to face spent-fuel risings and lack of reprocessing capacities, since the mid-seventies some countries are considering the possibility of direct spent-fuel disposal without reprocessing. These two options are discussed in terms of long-term waste management. Because of the types of waste conditioning and packaging adopted with present reprocessing technology, in that case long-term safety, after a few centuries, relies completely on the geological barriers. On the other hand, long-term safety with the second option is based essentially on the retention properties of uranium oxide with respect to actinides. Finally, alternatives such as chemical partitioning of minor actinides followed by their transmutation, either in reactors or using high-energy particle accelerators, are under discussion. Apart from the standard reprocessing (after a cooling period of 3-5 years), all the other options called for a long period (50 years) of interim storage, preventing the adoption of irreversible, costly and not well proved waste management solutions, and leaving time to develop and assess these alternative methods.

  4. Neutralization of acid mine drainage using the final product from CO2 emissions capture with alkaline paper mill waste.

    PubMed

    Pérez-López, Rafael; Castillo, Julio; Quispe, Dino; Nieto, José Miguel

    2010-05-15

    In this study, experiments were conducted to investigate the applicability of low-cost alkaline paper mill wastes as acidity neutralizing agents for treatment of acid mine drainage (AMD). Paper wastes include a calcium mud by-product from kraft pulping, and a calcite powder from a previous study focused on sequestering CO(2) by carbonation of calcium mud. The neutralization process consisted of increase of pH by alkaline additive dissolution, decrease of metals solubility and precipitation of gypsum and poorly crystallized Fe-Al oxy-hydroxides/oxy-hydroxysulphates, which acted as a sink for trace elements to that extent that solutions reached the pre-potability requirements of water for human consumption. This improvement was supported by geochemical modelling of solutions using PHREEQC software, and observations by scanning electron microscope and X-ray diffraction of reaction products. According to PHREEQC simulations, the annual amount of alkaline additive is able to treat AMD (pH 3.63, sulphate 3800 mg L(-1), iron 348 mg L(-1)) with an average discharge of about 114 and 40 Ls(-1) for calcium mud and calcite powder, respectively. Likewise, given the high potential of calcium mud to sequester CO(2) and of resulting calcite powder to neutralize AMD, paper wastes could be a promising solution for facing this double environmental problem.

  5. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... notification of shipment of irradiated reactor fuel and nuclear waste. (a) As specified in paragraphs (b), (c... of the shipper, carrier, and receiver of the irradiated reactor fuel or nuclear waste shipment; (2) A description of the irradiated reactor fuel or nuclear waste contained in the shipment, as specified in...

  6. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... notification of shipment of irradiated reactor fuel and nuclear waste. (a) As specified in paragraphs (b), (c... of the shipper, carrier, and receiver of the irradiated reactor fuel or nuclear waste shipment; (2) A description of the irradiated reactor fuel or nuclear waste contained in the shipment, as specified in...

  7. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... notification of shipment of irradiated reactor fuel and nuclear waste. (a) As specified in paragraphs (b), (c... advance notification of shipment of irradiated reactor fuel or nuclear waste must contain the following... irradiated reactor fuel or nuclear waste shipment; (2) A description of the irradiated reactor fuel...

  8. Can Shale Safely Host U.S. Nuclear Waste?

    NASA Astrophysics Data System (ADS)

    Neuzil, C. E.

    2013-07-01

    Even as cleanup efforts after Japan's Fukushima disaster offer a stark reminder of the spent nuclear fuel (SNF) stored at nuclear plants worldwide, the decision in 2009 to scrap Yucca Mountain as a permanent disposal site has dimmed hope for a repository for SNF and other high-level nuclear waste (HLW) in the United States anytime soon. About 70,000 metric tons of SNF are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers [Blue Ribbon Commission on America's Nuclear Future, 2012].

  9. Radioactive Waste Management in Non-Nuclear Countries - 13070

    SciTech Connect

    Kubelka, Dragan; Trifunovic, Dejan

    2013-07-01

    This paper challenges internationally accepted concepts of dissemination of responsibilities between all stakeholders involved in national radioactive waste management infrastructure in the countries without nuclear power program. Mainly it concerns countries classified as class A and potentially B countries according to International Atomic Energy Agency. It will be shown that in such countries long term sustainability of national radioactive waste management infrastructure is very sensitive issue that can be addressed by involving regulatory body in more active way in the infrastructure. In that way countries can mitigate possible consequences on the very sensitive open market of radioactive waste management services, comprised mainly of radioactive waste generators, operators of end-life management facilities and regulatory body. (authors)

  10. Analysis of mercury in simulated nuclear waste

    SciTech Connect

    Policke, T.A.; Johnson, L.C.; Best, D.R.

    1991-12-31

    Mercury, Hg, is a non-radioactive component in the High Level Waste at the Savannah River Site (SRS). Thus, it is a component of the Defense Waste Processing Facility`s (DWPF) process streams. It is present because mercuric nitrate (Hg(NO{sub 3}){sub 2}) is used to dissolve spent fuel rods. Since mercury halides are extremely corrosive, especially at elevated temperatures such as those seen in a melter (1150{degrees}C), its concentration throughout the process needs to be monitored so that it is at an acceptable level prior to reaching the melter off-gas system. The Hg can be found in condensates and sludge feeds and throughout the process and process lines, i.e., at any sampling point. The different samples types that require Hg determinations in the process streams are: (1) sludges, which may be basic or acidic and may or may not include aromatic organics, (2) slurries, which are sludges with frit and will always contain organics (formate and aromatics), and (3) condensates, from feed prep and melter off-gas locations. The condensates are aqueous and the mercury may exist as a complex mixture of halides, oxides, and metal, with levels between 10 and 100 ppm. The mercury in the sludges and slurries can be Hg{sup 0}, Hg{sup +1}, or Hg{sup +2}, with levels between 200 and 3000 ppm, depending upon the location, both time and position, of sampling. For DWPF, both total and soluble Hg concentrations need to be determined. The text below describes how these determinations are being made by the Defense Waste Processing Technology (DWPT) Analytical Laboratory at the Savannah River Site. Both flame atomic absorption (FAA) and cold vapor atomic (CVAA) measurements are discussed. Also, the problems encountered in the steps toward measuring HG in these samples types of condensates and sludges are discussed along with their solutions.

  11. Analysis of mercury in simulated nuclear waste

    SciTech Connect

    Policke, T.A.; Johnson, L.C.; Best, D.R.

    1991-01-01

    Mercury, Hg, is a non-radioactive component in the High Level Waste at the Savannah River Site (SRS). Thus, it is a component of the Defense Waste Processing Facility's (DWPF) process streams. It is present because mercuric nitrate (Hg(NO{sub 3}){sub 2}) is used to dissolve spent fuel rods. Since mercury halides are extremely corrosive, especially at elevated temperatures such as those seen in a melter (1150{degrees}C), its concentration throughout the process needs to be monitored so that it is at an acceptable level prior to reaching the melter off-gas system. The Hg can be found in condensates and sludge feeds and throughout the process and process lines, i.e., at any sampling point. The different samples types that require Hg determinations in the process streams are: (1) sludges, which may be basic or acidic and may or may not include aromatic organics, (2) slurries, which are sludges with frit and will always contain organics (formate and aromatics), and (3) condensates, from feed prep and melter off-gas locations. The condensates are aqueous and the mercury may exist as a complex mixture of halides, oxides, and metal, with levels between 10 and 100 ppm. The mercury in the sludges and slurries can be Hg{sup 0}, Hg{sup +1}, or Hg{sup +2}, with levels between 200 and 3000 ppm, depending upon the location, both time and position, of sampling. For DWPF, both total and soluble Hg concentrations need to be determined. The text below describes how these determinations are being made by the Defense Waste Processing Technology (DWPT) Analytical Laboratory at the Savannah River Site. Both flame atomic absorption (FAA) and cold vapor atomic (CVAA) measurements are discussed. Also, the problems encountered in the steps toward measuring HG in these samples types of condensates and sludges are discussed along with their solutions.

  12. Nevada Nuclear Waste Storage Investigations: Quality

    NASA Astrophysics Data System (ADS)

    1980-08-01

    The geohydrologic setting and underground rock masses of the Nevada Test Site and contiguous areas were evaluated to determine whether a suitable site exists for constructing a repository for isolating highly radioactive solid wastes. A quality assurance program which conforms to the criteria given in the Code of Federal Regulations is needed to control the quality aspects of the work. This Quality Assurance Plan describes the general quality assurance program for the overall project under which the quality assurance programs of the individual participating organizations and support contractors are to operate.

  13. DEVELOPMENT OF GLASS COMPOSITIONS TO IMMOBILIZE ALKALI, ALKALINE EARTH, LANTHANIDE AND TRANSITION METAL FISSION PRODUCTS FROM NUCLEAR FUEL REPROCESSING

    SciTech Connect

    Marra, J.; Billings, A.

    2009-06-24

    The Advanced Fuel Cycle Initiative (AFCI) waste management strategy revolves around specific treatment of individual or groups of separated waste streams. A goal for the separations processes is to efficiently manage the waste to be dispositioned as high level radioactive waste. The Advanced Fuel Cycle Initiative (AFCI) baseline technology for immobilization of the lanthanide (Ln) and transition metal fission product (TM) wastes is vitrification into a borosilicate glass. A current interest is to evaluate the feasibility of vitrifying combined waste streams to most cost effectively immobilize the wastes resulting from aqueous fuel reprocessing. Studies showed that high waste loadings are achievable for the Ln only (Option 1) stream. Waste loadings in excess of 60 wt % (on a calcined oxide basis) were demonstrated via a lanthanide borosilicate (LaBS) glass. The resulting glasses had excellent relative durability as determined by the Product Consistency Test (PCT). For a combined Ln and TM waste stream glass (Option 2), noble metal solubility was found to limit waste loading. However, the measured PCT normalized elemental releases for this glass were at least an order of magnitude below that of Environmental Assessment (EA) glass. Current efforts to evaluate the feasibility of vitrifying combined Ln, TM, alkali (Cs is the primary radionuclide of concern) and alkaline earth (Sr is the primary radionuclide of concern) wastes (Option 3) have shown that these approaches are feasible. However, waste loading limitations with respect to heat load (Cs/Sr loading), molybdenum solubility and/or noble metal solubility will likely be realized and must be considered in determining the cost effectiveness of these approaches.

  14. Nuclear waste package materials testing report: basaltic and tuffaceous environments

    SciTech Connect

    Bradley, D.J.; Coles, D.G.; Hodges, F.N.; McVay, G.L.; Westerman, R.E.

    1983-03-01

    The disposal of high-level nuclear wastes in underground repositories in the continental United States requires the development of a waste package that will contain radionuclides for a time period commensurate with performance criteria, which may be up to 1000 years. This report addresses materials testing in support of a waste package for a basalt (Hanford, Washington) or a tuff (Nevada Test Site) repository. The materials investigated in this testing effort were: sodium and calcium bentonites and mixtures with sand or basalt as a backfill; iron and titanium-based alloys as structural barriers; and borosilicate waste glass PNL 76-68 as a waste form. The testing also incorporated site-specific rock media and ground waters: Reference Umtanum Entablature-1 basalt and reference basalt ground water, Bullfrog tuff and NTS J-13 well water. The results of the testing are discussed in four major categories: Backfill Materials: emphasizing water migration, radionuclide migration, physical property and long-term stability studies. Structural Barriers: emphasizing uniform corrosion, irradiation-corrosion, and environmental-mechanical testing. Waste Form Release Characteristics: emphasizing ground water, sample surface area/solution volume ratio, and gamma radiolysis effects. Component Compatibility: emphasizing solution/rock, glass/rock, glass/structural barrier, and glass/backfill interaction tests. This area also includes sensitivity testing to determine primary parameters to be studied, and the results of systems tests where more than two waste package components were combined during a single test.

  15. Anticipating Potential Waste Acceptance Criteria for Defense Spent Nuclear Fuel

    SciTech Connect

    Rechard, R.P.; Lord, M.E.; Stockman, C.T.; McCurley, R.D.

    1997-12-31

    The Office of Environmental Management of the U.S. Department of Energy is responsible for the safe management and disposal of DOE owned defense spent nuclear fuel and high level waste (DSNF/DHLW). A desirable option, direct disposal of the waste in the potential repository at Yucca Mountain, depends on the final waste acceptance criteria, which will be set by DOE`s Office of Civilian Radioactive Waste Management (OCRWM). However, evolving regulations make it difficult to determine what the final acceptance criteria will be. A method of anticipating waste acceptance criteria is to gain an understanding of the DOE owned waste types and their behavior in a disposal system through a performance assessment and contrast such behavior with characteristics of commercial spent fuel. Preliminary results from such an analysis indicate that releases of 99Tc and 237Np from commercial spent fuel exceed those of the DSNF/DHLW; thus, if commercial spent fuel can meet the waste acceptance criteria, then DSNF can also meet the criteria. In large part, these results are caused by the small percentage of total activity of the DSNF in the repository (1.5%) and regulatory mass (4%), and also because commercial fuel cladding was assumed to provide no protection.

  16. Characterization of Oversized Crates containing Nuclear Waste

    SciTech Connect

    Berg, Randal K.; Haggard, Daniel L.; Hilliard, Jim; Mozhayev, Andrey V.

    2007-11-01

    The 212-N Building at the Hanford Site held fifteen large crates containing glove boxes and process equipment associated with the development and fabrication of mixed oxide (MOX) fuel. The gloveboxes and associated equipment originated from the 308 Building of the Hanford Site and had been placed in the crates after a process upset in the 1960s. The crates were transported to the 212-N Building and had been in storage since 1972. In an effort to reduce the hazard categorization of 212-N the crates were removed from the building and Nondestructive Assay (NDA) was performed to characterize the crate contents meeting both Safeguards and Waste Management interests. A measurement system consisting of four configurable neutron slab detectors and high purity germanium (HPGe) detectors was deployed. Since no viable information regarding the waste matrix and configuration was available it was essential to correct for attenuation with a series of transmission measurements using californium and europium sources for both neutron and gamma applications. The gamma and neutron results obtained during this measurement campaign are compared and discussed in the paper.

  17. A proliferation of nuclear waste for the Southeast.

    PubMed

    Alvarez, Robert; Smith, Stephen

    2007-12-01

    The U.S. Department of Energy's (DOE) Global Nuclear Energy Partnership (GNEP) is being promoted as a program to bring about the expansion of worldwide nuclear energy. Here in the U.S. much of this proposed nuclear power expansion is slated to happen in the Southeast, including here in South Carolina. Under the GNEP plan, the United States and its nuclear partners would sell nuclear power plants to developing nations that agree not to pursue technologies that would aid nuclear weapons production, notably reprocessing and uranium enrichment. As part of the deal, the United States would take highly radioactive spent ("used") fuel rods to a reprocessing center in this country. Upon analysis of the proposal, it is clear that DOE lacks a credible plan for the safe management and disposal of radioactive wastes stemming from the GNEP program and that the high costs and possible public health and environmental impacts from the program pose significant risks, especially to this region. Given past failures to address waste problems before they were created, DOE's rush to invest major public funds for deployment of reprocessing should be suspended.

  18. Case histories of EA documents for nuclear waste

    SciTech Connect

    Vocke, R.W.

    1985-01-01

    Nuclear power programs and policies in the United States have been subject to environmental assessment under the National Environmental Policy Act (NEPA) since 1971. NEPA documentation prepared for programmatic policy decision-making within the nuclear fuel cycle and concurrent federal policy are examined as they relate to radioactive waste management in this paper. Key programmatic environmental impact statements that address radioactive waste management include: the Atomic Energy Commission document on management of commercial high-level and transuranium-contaminated radioactive waste, which focussed on development of engineered retrievable surface storage facilities (RSSF); the Nuclear Regulatory Commission (NRC) document on use of recycled plutonium in mixed oxide fuel in light water cooled reactors, which focussed on plutonium recycle and RSSF; the NRC statement on handling of spent light water power reactor fuel, which focussed on spent fuel storage; and the Department of Energy (DOE) statement on management of commercially generated radioactive wastes, which focussed on development of deep geologic repositories. DOE is currently pursuing the deep geologic repository option, with monitored retrievable storage as a secondary option.

  19. The suitability of a supersulfated cement for nuclear waste immobilisation

    NASA Astrophysics Data System (ADS)

    Collier, N. C.; Milestone, N. B.; Gordon, L. E.; Ko, S.-C.

    2014-09-01

    Composite cements based on ordinary Portland cement are used in the UK as immobilisation matrices for low and intermediate level nuclear wastes. However, the high pore solution pH causes corrosion of some metallic wastes and undesirable expansive reactions, which has led to alternative cementing systems being examined. We have investigated the physical, chemical and microstructural properties of a supersulfated cement in order to determine its applicability for use in nuclear waste encapsulation. The hardened supersulfated cement paste appeared to have properties desirable for use in producing encapsulation matrices, but the high powder specific surface resulted in a matrix with high porosity. Ettringite and calcium silicate hydrate were the main phases formed in the hardened cement paste and anhydrite was present in excess. The maximum rate of heat output during hydration of the supersulfated cement paste was slightly higher than that of a 9:1 blastfurnace slag:ordinary Portland cement paste commonly used by the UK nuclear waste processing industry, although the total heat output of the supersulfated cement paste was lower. The pH was also significantly lower in the supersulfated cement paste. Aluminium hydroxide was formed on the surface of aluminium metal encapsulated in the cement paste and ettringite was detected between the aluminium hydroxide and the hardened cement paste.

  20. Ventilation planning for a prospective nuclear waste repository

    SciTech Connect

    Wallace, K.G. Jr.

    1987-12-31

    In 1982, the US Congress passed the Nuclear Waste Policy Act to provide for the development of underground repositories for spent nuclear fuel. This development will be managed by the United States Department of Energy. In 1986, the President selected three areas for site characterization to determine their suitability for the development of an underground repository; those sites were: (1) A site in volcanic tuff located at Yucca Mountain in Nevada, (2) a site in bedded salt located in Deaf Smith County in Texas, and (3) a site in basalt located in Hanford, Washington. At present conceptual repository designs are being developed for each site. A key element of a repository design is the underground ventilation system required to support construction, nuclear waste emplacement, and potential waste retrieval. This paper describes the preliminary ventilation systems designed for the repository in tuff. The concept provides separate ventilation systems for the construction and waste emplacement activities. The paper further describes the means by which acceptable environmental conditions will be re-established to allow re-entry into previously closed rooms for the purpose of inspection, maintenance or retrieval.

  1. Annular air space effects on nuclear waste canister temperatures in a deep geologic waste repository

    SciTech Connect

    Lowry, W.E.; Cheung, H.; Davis, B.W.

    1980-05-13

    Air spaces in a deep geologic repository for nuclear high level waste will have an important effect on the long-term performance of the waste package. The important temperature effects of an annular air gap surrounding a high level waste canister are determined through 3-D numerical modeling. Air gap properties and parameters specifically analyzed and presented are the air gap size, surfaces emissivity, presence of a sleeve, and initial thermal power generation rate; particular emphasis was placed on determining the effect of these variables have on the canister surface temperature. Finally a discussion based on modeling results is presented which specifically relates the results to NRC regulatory considerations.

  2. Review: Waste-Pretreatment Technologies for Remediation of Legacy Defense Nuclear Wastes

    SciTech Connect

    Wilmarth, William R.; Lumetta, Gregg J.; Johnson, Michael E.; Poirier, Micheal R.; Thompson, Major C.; Suggs, Patricia C.; Machara, N.

    2011-01-13

    The U.S. Department of Energy (DOE) is responsible for retrieving, immobilizing, and disposing of radioactive waste that has been generated during the production of nuclear weapons in the United States. The vast bulk of this waste material is stored in underground tanks at the Savannah River Site in South Carolina and the Hanford Site in Washington State. The general strategy for treating the radioactive tank waste consists of first separating the waste into high-level and low-activity fractions. This initial partitioning of the waste is referred to as pretreatment. Following pretreatment, the high-level fraction will be immobilized in a glass form suitable for disposal in a geologic repository. The low-activity waste will be immobilized in a waste form suitable for disposal at the respective site. This paper provides a review of recent developments in the application of pretreatment technologies to the processing of the Hanford and Savannah River radioactive tank wastes. Included in the review are discussions of 1) solid/liquid separations methods, 2) cesium separation technologies, and 3) other separations critical to the success of the DOE tank waste remediation effort. Also included is a brief discussion of the different requirements and circumstances at the two DOE sites that have in some cases led to different choices in pretreatment technologies.

  3. Waste package performance evaluations for the proposed high-level nuclear waste repository at Yucca Mountain.

    PubMed

    Mon, Kevin G; Bullard, Bryan E; Mehta, Sunil; Lee, Joon H

    2004-04-01

    The evaluation studies of the proposed repository for long-term storage of spent nuclear fuel and high-level nuclear waste at Yucca Mountain, Nevada, are underway. Fulfillment of the requirements for limiting dose to the public, which includes containment of the radioactive waste emplaced in the proposed repository and subsequent slow release of radionuclides from the Engineered Barrier System (EBS) into the geosphere, will rely on a robust waste container design, among other EBS components. Part of the evaluation process involves sensitivity studies aimed at elucidating which model parameters contribute most to the waste package and overlying drip shield degradation characteristics. The model parameters identified for this study include (1) general corrosion rate parameters and (2) stress corrosion cracking (SCC) parameters. Temperature dependence and parameter uncertainty are evaluated for the general corrosion rate model parameters while for the SCC model parameters, uncertainty treatment of stress intensity factor, crack initiation threshold, and manufacturing flaw orientations are evaluated. Based on these evaluations new uncertainty distributions are generated and recommended for future analyses. Also, early waste package failures due to improper heat treatment were added to the waste package degradation model. The results of these investigations indicate that the waste package failure profiles are governed by the manufacturing flaw orientation model parameters.

  4. Groundwater chemistry of a nuclear waste reposoitory in granite bedrock

    SciTech Connect

    Rydberg, J.

    1981-09-01

    This report concerns the prediction of the maximum dissolution rate for nuclear waste stored in the ground. That information is essential in judging the safety of a nuclear waste repository. With a limited groundwater flow, the maximum dissolution rate coincides with the maximum solubility. After considering the formation and composition of deep granite bedrock groundwater, the report discusses the maximum solubility in such groundwater of canister materials, matrix materials and waste elements. The parameters considered are pH, Eh and complex formation. The use of potential-pH (Pourbaix) diagrams is stressed; several appendixes are included to help in analyzing such diagrams. It is repeatedly found that desirable basic information on solution chemistry is lacking, and an international cooperative research effort is recommended. The report particularly stresses the lack of reliable data about complex formation and hydrolysis of the actinides. The Swedish Nuclear Fuel Safety (KBS) study has been used as a reference model. Notwithstanding the lack of reliable chemical data, particularly for the actinides and some fission products, a number of essential conclusions can be drawn about the waste handling model chosen by KBS. (1) Copper seems to be highly resistant to groundwater corrosion. (2) Lead and titanium are also resistant to groundwater, but inferior to copper. (3) Iron is not a suitable canister material. (4) Alumina (Al/sub 2/O/sub 3/) is not a suitable canister material if groundwater pH goes up to or above 10. Alumina is superior to copper at pH < 9, if there is a risk of the groundwater becoming oxidizing. (5) The addition of vivianite (ferrous phosphate) to the clay backfill around the waste canisters improves the corrosion resistance of the metal canisters, and reduces the solubility of many important waste elements. This report does not treat the migration of dissolved species through the rock.

  5. Graphite matrix materials for nuclear waste isolation

    SciTech Connect

    Morgan, W.C.

    1981-06-01

    At low temperatures, graphites are chemically inert to all but the strongest oxidizing agents. The raw materials from which artificial graphites are produced are plentiful and inexpensive. Morover, the physical properties of artificial graphites can be varied over a very wide range by the choice of raw materials and manufacturing processes. Manufacturing processes are reviewed herein, with primary emphasis on those processes which might be used to produce a graphite matrix for the waste forms. The approach, recommended herein, involves the low-temperature compaction of a finely ground powder produced from graphitized petroleum coke. The resultant compacts should have fairly good strength, low permeability to both liquids and gases, and anisotropic physical properties. In particular, the anisotropy of the thermal expansion coefficients and the thermal conductivity should be advantageous for this application. With two possible exceptions, the graphite matrix appears to be superior to the metal alloy matrices which have been recommended in prior studies. The two possible exceptions are the requirements on strength and permeability; both requirements will be strongly influenced by the containment design, including the choice of materials and the waste form, of the multibarrier package. Various methods for increasing the strength, and for decreasing the permeability of the matrix, are reviewed and discussed in the sections in Incorporation of Other Materials and Elimination of Porosity. However, it would be premature to recommend a particular process until the overall multi-barrier design is better defined. It is recommended that increased emphasis be placed on further development of the low-temperature compacted graphite matrix concept.

  6. Combined Utilization of Cation Exchanger and Neutral Receptor to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts

    SciTech Connect

    Levitskaia, Tatiana G.; Lumetta, Gregg J.; Moyer, Bruce A.

    2004-03-29

    In this report, novel approaches to the selective liquid-liquid extraction separation of sodium hydroxide and sodium nitrate from high-level alkaline tank waste will be discussed. Sodium hydroxide can be successfully separated from alkaline tank-waste supernatants by weakly acidic lipophilic hydroxy compounds via a cation-exchange mechanism referred to as pseudo hydroxide extraction. In a multi-cycle process, as sodium hydroxide in the aqueous phase becomes depleted, it is helpful to have a neutral sodium receptor in the extraction system to exploit the high nitrate concentration in the waste solution to promote sodium removal by an ion-pair extraction process. Simultaneous utilization of an ionizable organic hydroxy compound and a neutral extractant (crown ether) in an organic phase results in the synergistic enhancement of ion exchange and improved separation selectivity due to the receptor's strong and selective sodium binding. Moreover, combination of the hydroxy compound and the crown ether provides for mutually increased solubility, even in a non-polar organic solvent. Accordingly, application of Isopar{reg_sign} L, a kerosene-like alkane solvent, becomes feasible. This investigation involves examination of such dual-mechanism extraction phases for sodium extraction from simulated and actual salt cake waste solutions. Sodium salts can be regenerated upon the contact of the loaded extraction phases with water. Finally, conditions of potential extraction/strip cycling will be discussed.

  7. Early containment of high-alkaline solution simulating low-level radioactive waste stream in clay-bearing blended cement

    SciTech Connect

    Kruger, A.A.; Olson, R.A.; Tennis, P.D.

    1995-04-01

    Portland cement blended with fly ash and attapulgite clay was mixed with high-alkaline solution simulating low-level radioactive waste stream at a one-to-one weight ratio. Mixtures were adiabatically and isothermally cured at various temperatures and analyzed for phase composition, total alkalinity, pore solution chemistry, and transport properties as measured by impedance spectroscopy. Total alkalinity is characterized by two main drops. The early one corresponds to a rapid removal of phosphorous, aluminum, sodium, and to a lesser extent potassium solution. The second drop from about 10 h to 3 days is mainly associated with the removal of aluminum, silicon, and sodium. Thereafter, the total alkalinity continues descending, but at a lower rate. All pastes display a rapid flow loss that is attributed to an early precipitation of hydrated products. Hemicarbonate appears as early as one hour after mixing and is probably followed by apatite precipitation. However, the former is unstable and decomposes at a rate that is inversely related to the curing temperature. At high temperatures, zeolite appears at about 10 h after mixing. At 30 days, the stabilized crystalline composition Includes zeolite, apatite and other minor amounts of CaCO{sub 3}, quartz, and monosulfate Impedance spectra conform with the chemical and mineralogical data. The normalized conductivity of the pastes shows an early drop, which is followed by a main decrease from about 12 h to three days. At three days, the permeability of the cement-based waste as calculated by Katz-Thompson equation is over three orders of magnitude lower than that of ordinary portland cement paste. However, a further decrease in the calculated permeability is questionable. Chemical stabilization is favorable through incorporation of waste species into apatite and zeolite.

  8. Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash.

    PubMed

    Diaz-Loya, E Ivan; Allouche, Erez N; Eklund, Sven; Joshi, Anupam R; Kupwade-Patil, Kunal

    2012-08-01

    Municipal solid waste (MSW) incineration is a common and effective practice to reduce the volume of solid waste in urban areas. However, the byproduct of this process is a fly ash (IFA), which contains large quantities of toxic contaminants. The purpose of this research study was to analyze the chemical, physical and mechanical behaviors resulting from the gradual introduction of IFA to an alkaline activated coal fly ash (CFA) matrix, as a mean of stabilizing the incinerator ash for use in industrial construction applications, where human exposure potential is limited. IFA and CFA were analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD) and Inductive coupled plasma (ICP) to obtain a full chemical analysis of the samples, its crystallographic characteristics and a detailed count of the eight heavy metals contemplated in US Title 40 of the Code of Federal Regulations (40 CFR). The particle size distribution of IFA and CFA was also recorded. EPA's Toxicity Characteristic Leaching Procedure (TCLP) was followed to monitor the leachability of the contaminants before and after the activation. Also images obtained via Scanning Electron Microscopy (SEM), before and after the activation, are presented. Concrete made from IFA, CFA and IFA-CFA mixes was subjected to a full mechanical characterization; tests include compressive strength, flexural strength, elastic modulus, Poisson's ratio and setting time. The leachable heavy metal contents (except for Se) were below the maximum allowable limits and in many cases even below the reporting limit. The leachable Chromium was reduced from 0.153 down to 0.0045 mg/L, Arsenic from 0.256 down to 0.132 mg/L, Selenium from 1.05 down to 0.29 mg/L, Silver from 0.011 down to .001 mg/L, Barium from 2.06 down to 0.314 mg/L and Mercury from 0.007 down to 0.001 mg/L. Although the leachable Cd exhibited an increase from 0.49 up to 0.805 mg/L and Pd from 0.002 up to 0.029 mg/L, these were well below the maximum limits of 1.00 and 5

  9. Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash

    SciTech Connect

    Ivan Diaz-Loya, E.; Allouche, Erez N.; Eklund, Sven; Joshi, Anupam R.; Kupwade-Patil, Kunal

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Incinerator fly ash (IFA) is added to an alkali activated coal fly ash (CFA) matrix. Black-Right-Pointing-Pointer Means of stabilizing the incinerator ash for use in construction applications. Black-Right-Pointing-Pointer Concrete made from IFA, CFA and IFA-CFA mixes was chemically characterized. Black-Right-Pointing-Pointer Environmentally friendly solution to IFA disposal by reducing its toxicity levels. - Abstract: Municipal solid waste (MSW) incineration is a common and effective practice to reduce the volume of solid waste in urban areas. However, the byproduct of this process is a fly ash (IFA), which contains large quantities of toxic contaminants. The purpose of this research study was to analyze the chemical, physical and mechanical behaviors resulting from the gradual introduction of IFA to an alkaline activated coal fly ash (CFA) matrix, as a mean of stabilizing the incinerator ash for use in industrial construction applications, where human exposure potential is limited. IFA and CFA were analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD) and Inductive coupled plasma (ICP) to obtain a full chemical analysis of the samples, its crystallographic characteristics and a detailed count of the eight heavy metals contemplated in US Title 40 of the Code of Federal Regulations (40 CFR). The particle size distribution of IFA and CFA was also recorded. EPA's Toxicity Characteristic Leaching Procedure (TCLP) was followed to monitor the leachability of the contaminants before and after the activation. Also images obtained via Scanning Electron Microscopy (SEM), before and after the activation, are presented. Concrete made from IFA, CFA and IFA-CFA mixes was subjected to a full mechanical characterization; tests include compressive strength, flexural strength, elastic modulus, Poisson's ratio and setting time. The leachable heavy metal contents (except for Se) were below the maximum allowable limits and in many cases

  10. pH neutralization and zonation in alkaline-saline tank waste plumes.

    PubMed

    Wan, Jiamin; Larsen, Joern T; Tokunaga, Tetsu K; Zheng, Zuoping

    2004-03-01

    At the Hanford Site in Washington State, the pH values of contaminant plumes resulting from leaking of initially highly alkaline-saline radioactive waste solutions into the subsurface are now found to be substantially neutralized. However, the nature of plume pH neutralization has not previously been understood. As a master geochemical variable, pH needs to be understood in order to predict the fate and transport of contaminants carried by the waste plumes. Through this laboratory study, we found that the plume pH values spanned a broad range from 14 (within the near-source region) down to the value of 7 (lower than the pH value of the initial soil solution) while the plume was still connected to an actively leaking source. We defined two zones within a plume: the silicate dissolution zone (SDZ, pH 14-10) and the neutralized zone (NZ, pH 10-7). Quartz dissolution at elevated temperature and precipitation of secondary silicates (including sodium metasilicate, cancrinite, and zeolites) are the key reactions responsible for the pH neutralization within the SDZ. The rapid and thorough cation exchange of Na+ replacing Ca2+/Mg2+, combined with transport, resulted in a dynamic Ca2+/Mg2+-enriched plume front. Subsequent precipitation of calcite, sodium silicate, and possibly talc led to dramatically reduced pH within the plume front and the neutralized zone. During aging (after the plume source became inactive), continued quartz dissolution and the secondary silicate precipitation drove the pH value lower, toward pH 11 at equilibrium within the SDZ, whereas the pH values in the NZ remained relatively unchanged with time. A pH profile of 11 from the plume source to pH 7 at the plume front is expected for a historical plume. This laboratory-based study provided realistic plume pH profiles (consistent with that measured from borehole samples) and identified underlying mechanisms responsible for pH evolution.

  11. "Hanford: A Conversation About Nuclear Waste and Cleanup"

    SciTech Connect

    Gephart, Roy E.

    2003-05-10

    In ''Hanford: A Conversation about Nuclear Waste and Cleanup'', Roy Gephart takes us on a journey through a world of facts, values, conflicts, and choices facing the most complex environmental cleanup project in the United States, the U.S. Department of Energy's Hanford Site. Starting with the top-secret Manhattan Project, Hanford was used to create tons of plutonium for nuclear weapons. Hundreds of tons of waste remain. In an easy-to-read, illustrated text, Gephart crafts the story of Hanford becoming the world's first nuclear weapons site to release large amounts of contaminants into the environment. This was at a time when radiation biology was in its infancy, industry practiced unbridled waste dumping, and the public trusted what it was told. The plutonium market stalled with the end of the Cold War. Public accountability and environmental compliance ushered in a new cleanup mission. Today, Hanford is driven by remediation choices whose outcomes remain uncertain. It's a story whose epilogue will be written by future generations. This book is an information resource, written for the general reader as well as the technically trained person wanting an overview of Hanford and cleanup issues facing the nuclear weapons complex. Each chapter is a topical mini-series. It's an idea guide that encourages readers to be informed consumers of Hanford news, to recognize that knowledge, high ethical standards, and social values are at the heart of coping with Hanford's past and charting its future. Hanford history is a window into many environmental conflicts facing our nation; it's about building upon success and learning from failure. And therein lies a key lesson, when powerful interests are involved, no generation is above pretense. Roy E. Gephart is a geohydrologist and senior program manager at the Pacific Northwest National Laboratory, Richland, Washington. He has 30 years experience in environmental studies and the nuclear waste industry.

  12. Tokamak Transmutation of (nuclear) Waste (TTW): Parametric studies

    NASA Astrophysics Data System (ADS)

    Cheng, E. T.; Krakowski, R. A.; Peng, Y. K. M.

    Radioactive waste generated as part of the commercial-power and defense nuclear programs can be either stored or transmuted. The latter treatment requires a capital-intensive neutron source and is reserved for particularly hazardous and long-lived actinide and fission-product waste. A comparative description of fusion-based transmutation is made on the basis of rudimentary estimates of ergonic performance and transmutation capacities versus inventories for both ultra-low aspect-ratio (spherical torus, ST) and conversional (aspect-ratio) tokamak fusion-power-core drivers. The parametric systems studies reported herein provides a preamble to more-detailed, cost-based systems analyses.

  13. Process for recovery of palladium from nuclear fuel reprocessing wastes

    DOEpatents

    Campbell, D.O.; Buxton, S.R.

    1980-06-16

    Palladium is selectively removed from spent nuclear fuel reprocessing waste by adding sugar to a strong nitric acid solution of the waste to partially denitrate the solution and cause formation of an insoluble palladium compound. The process includes the steps of: (a) adjusting the nitric acid content of the starting solution to about 10 M; (b) adding 50% sucrose solution in an amount sufficient to effect the precipitation of the palladium compound; (c) heating the solution at reflux temperature until precipitation is complete; and (d) centrifuging the solution to separate the precipitated palladium compound from the supernatant liquid.

  14. Process for recovery of palladium from nuclear fuel reprocessing wastes

    DOEpatents

    Campbell, David O.; Buxton, Samuel R.

    1981-01-01

    Palladium is selectively removed from spent nuclear fuel reprocessing waste by adding sugar to a strong nitric acid solution of the waste to partially denitrate the solution and cause formation of an insoluble palladium compound. The process includes the steps of: (a) adjusting the nitric acid content of the starting solution to about 10 M, (b) adding 50% sucrose solution in an amount sufficient to effect the precipitation of the palladium compound, (c) heating the solution at reflux temperature until precipitation is complete, and (d) centrifuging the solution to separate the precipitated palladium compound from the supernatant liquid.

  15. Tokamak transmutation of (nuclear) waste (TTW): Parametric studies

    SciTech Connect

    Cheng, E.T.; Krakowski, R.A.; Peng, Y.K.M.

    1994-06-01

    Radioactive waste generated as part of the commercial-power and defense nuclear programs can be either stored or transmuted. The latter treatment requires a capital-intensive neutron source and is reserved for particularly hazardous and long-lived actinide and fission-product waste. A comparative description of fusion-based transmutation is made on the basis of rudimentary estimates of ergonic performance and transmutation capacities versus inventories for both ultra-low-aspect-ratio (spherical torus, ST) and conversional (aspect-ratio) tokamak fusion-power-core drivers. The parametric systems studies reported herein provides a preamble to more-detailed, cost-based systems analyses.

  16. Nuclear waste management and the use of the sea. Special report

    SciTech Connect

    Not Available

    1984-04-01

    This report reviews the current situation on nuclear-waste-disposal policies in the United States and elsewhere and relates these policies to implications for the oceans. The report describes the worldwide inventory of radioactive waste, the varying types of radioactive wastes, international and domestic laws governing radioactive waste disposal, scientific analysis of marine radioactivity, and possible U.S. proposals on ocean disposal of nuclear waste. Detailed appendices describe nuclear and health physics, waste management strategies of other nations, prior U.S. dumping of radioactive wastes, signatories to the London Dumping Convention, specific case histories, among others.

  17. Sorption of strontium on uranyl peroxide: implications for a high-level nuclear waste repository.

    PubMed

    Sureda, Rosa; Martínez-Lladó, Xavier; Rovira, Miquel; de Pablo, Joan; Casas, Ignasi; Giménez, Javier

    2010-09-15

    Strontium-90 is considered the most important radioactive isotope in the environment and one of the most frequently occurring radionuclides in groundwaters at nuclear facilities. The uranyl peroxide studtite (UO2O2 . 4H2O) has been observed to be formed in spent nuclear fuel leaching experiments and seems to have a relatively high sorption capacity for some radionuclides. In this work, the sorption of strontium onto studtite is studied as a function of time, strontium concentration in solution and pH. The main results obtained are (a) sorption is relatively fast although slower than for cesium; (b) strontium seems to be sorbed via a monolayer coverage of the studtite surface, (c) sorption has a strong dependence on ionic strength, is negligible at acidic pH, and increases at neutral to alkaline pH (almost 100% of the strontium in solution is sorbed above pH 10). These results point to uranium secondary solid phase formation on the spent nuclear fuel as an important mechanism for strontium retention in a high-level nuclear waste repository (HLNW).

  18. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs, D

    2007-11-15

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90 and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction, for {sup 137}Cs removal. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239 and Pu-240. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.

  19. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs D. T.; Poirier, M. R.; Barnes, M. J.; Stallings, M. E.; Nyman, M. D.

    2005-11-22

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 137}Cs, {sup 90}Sr and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include caustic side solvent extraction, for {sup 137}Cs removal, and sorption of {sup 90}Sr and alpha-emitting radionuclides onto monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu and {sup 240}Pu. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the baseline MST material.

  20. Effects of Heat Generation on Nuclear Waste Disposal in Salt

    NASA Astrophysics Data System (ADS)

    Clayton, D. J.

    2008-12-01

    Disposal of nuclear waste in salt is an established technology, as evidenced by the successful operations of the Waste Isolation Pilot Plant (WIPP) since 1999. The WIPP is located in bedded salt in southeastern New Mexico and is a deep underground facility for transuranic (TRU) nuclear waste disposal. There are many advantages for placing radioactive wastes in a geologic bedded-salt environment. One desirable mechanical characteristic of salt is that it flows plastically with time ("creeps"). The rate of salt creep is a strong function of temperature and stress differences. Higher temperatures and deviatoric stresses increase the creep rate. As the salt creeps, induced fractures may be closed and eventually healed, which then effectively seals the waste in place. With a backfill of crushed salt emplaced around the waste, the salt creep can cause the crushed salt to reconsolidate and heal to a state similar to intact salt, serving as an efficient seal. Experiments in the WIPP were conducted to investigate the effects of heat generation on the important phenomena and processes in and around the repository (Munson et al. 1987; 1990; 1992a; 1992b). Brine migration towards the heaters was induced from the thermal gradient, while salt creep rates showed an exponential dependence on temperature. The project "Backfill and Material Behavior in Underground Salt Repositories, Phase II" (BAMBUS II) studied the crushed salt backfill and material behavior with heat generation at the Asse mine located near Remlingen, Germany (Bechthold et al. 2004). Increased salt creep rates and significant reconsolidation of the crushed salt were observed at the termination of the experiment. Using the data provided from both projects, exploratory modeling of the thermal-mechanical response of salt has been conducted with varying thermal loading and waste spacing. Increased thermal loading and decreased waste spacing drive the system to higher temperatures, while both factors are desired to

  1. ``Recycling'' Nuclear Power Plant Waste: Technical Difficulties and Proliferation Concerns

    NASA Astrophysics Data System (ADS)

    Lyman, Edwin

    2007-04-01

    One of the most vexing problems associated with nuclear energy is the inability to find a technically and politically viable solution for the disposal of long-lived radioactive waste. The U.S. plan to develop a geologic repository for spent nuclear fuel at Yucca Mountain in Nevada is in jeopardy, as a result of managerial incompetence, political opposition and regulatory standards that may be impossible to meet. As a result, there is growing interest in technologies that are claimed to have the potential to drastically reduce the amount of waste that would require geologic burial and the length of time that the waste would require containment. A scenario for such a vision was presented in the December 2005 Scientific American. While details differ, these technologies share a common approach: they require chemical processing of spent fuel to extract plutonium and other long-lived actinide elements, which would then be ``recycled'' into fresh fuel for advanced reactors and ``transmuted'' into shorter-lived fission products. Such a scheme is the basis for the ``Global Nuclear Energy Partnership,'' a major program unveiled by the Department of Energy (DOE) in early 2006. This concept is not new, but has been studied for decades. Major obstacles include fundamental safety issues, engineering feasibility and cost. Perhaps the most important consideration in the post-9/11 era is that these technologies involve the separation of plutonium and other nuclear weapon-usable materials from highly radioactive fission products, providing opportunities for terrorists seeking to obtain nuclear weapons. While DOE claims that it will only utilize processes that do not produce ``separated plutonium,'' it has offered no evidence that such technologies would effectively deter theft. It is doubtful that DOE's scheme can be implemented without an unacceptable increase in the risk of nuclear terrorism.

  2. The role of frit in nuclear waste vitrification

    SciTech Connect

    Vienna, J.D.; Smith, P.A.; Dorn, D.A.; Hrma, P.

    1994-04-01

    Vitrification of nuclear waste requires additives which are often vitrified independently to form a frit. Frit composition is formulated to meet the needs of glass composition and processing. The effects of frit on melter feed and melt processing, glass acceptance, and waste loading is of practical interest in understanding the trade-offs associated with the competing demands placed on frit composition. Melter feed yield stress, viscosity and durability of frits and corresponding waste glasses as well as the kinetics of elementary melting processes have been measured. The results illustrate the competing requirements on frit. Four frits (FY91, FY93, HW39-4, and SR202) and simulated neutralized current acid waste (NCAW) were used in this study. The experimental evidence shows that optimization of frit for one processing related property often results in poorer performance for the remaining properties. The difficulties associated with maximum waste loading and durability are elucidated for glasses which could be processed using technology available for the previously proposed Hanford Waste Vitrification Plant.

  3. Dangers associated with civil nuclear power programmes: weaponization and nuclear waste.

    PubMed

    Boulton, Frank

    2015-07-24

    The number of nuclear power plants in the world rose exponentially to 420 by 1990 and peaked at 438 in 2002; but by 2014, as closed plants were not replaced, there were just 388. In spite of using more renewable energy, the world still relies on fossil fuels, but some countries plan to develop new nuclear programmes. Spent nuclear fuel, one of the most dangerous and toxic materials known, can be reprocessed into fresh fuel or into weapons-grade materials, and generates large amounts of highly active waste. This article reviews available literature on government and industry websites and from independent analysts on world energy production, the aspirations of the 'new nuclear build' programmes in China and the UK, and the difficulties in keeping the environment safe over an immense timescale while minimizing adverse health impacts and production of greenhouse gases, and preventing weaponization by non-nuclear-weapons states acquiring civil nuclear technology.

  4. Nuclear Waste Disposal in Space: BEP's Best Hope?

    SciTech Connect

    Coopersmith, Jonathan

    2006-05-02

    The best technology is worthless if it cannot find a market Beam energy propulsion (BEP) is a very promising technology, but faces major competition from less capable but fully developed conventional rockets. Rockets can easily handle projected markets for payloads into space. Without a new, huge demand for launch capability, BEP is unlikely to gain the resources it needs for development and application. Launching tens of thousands of tons of nuclear waste into space for safe and permanent disposal will provide that necessary demand while solving a major problem on earth. Several options exist to dispose of nuclear waste, including solar orbit, lunar orbit, soft lunar landing, launching outside the solar system, and launching into the sun.

  5. Alcohol-free alkoxide process for containing nuclear waste

    DOEpatents

    Pope, James M.; Lahoda, Edward J.

    1984-01-01

    Disclosed is a method of containing nuclear waste. A composition is first prepared of about 25 to about 80%, calculated as SiO.sub.2, of a partially hydrolyzed silicon compound, up to about 30%, calculated as metal oxide, of a partially hydrolyzed aluminum or calcium compound, about 5 to about 20%, calculated as metal oxide, of a partially hydrolyzed boron or calcium compound, about 3 to about 25%, calculated as metal oxide, of a partially hydrolyzed sodium, potassium or lithium compound, an alcohol in a weight ratio to hydrolyzed alkoxide of about 1.5 to about 3% and sufficient water to remove at least 99% of the alcohol as an azeotrope. The azeotrope is boiled off and up to about 40%, based on solids in the product, of the nuclear waste, is mixed into the composition. The mixture is evaporated to about 25 to about 45% solids and is melted and cooled.

  6. Workshop on fundamental geochemistry needs for nuclear waste isolation

    SciTech Connect

    Heiken, J.H.

    1985-09-01

    In their deliberations, workshop participants did not attempt to incorporate the constraints that the 1982 National Nuclear Waste Management Policy Act placed upon the site-specific investigations. In particular, there was no attempt to (1) identify the research areas that apply most strongly to a particular potential repository site, (2) identify the chronological time when the necessary data or knowledge could be available, or (3) include a sensitivity analysis to prioritize and limit data needs. The workshop participants felt these are the purview of the site-specific investigations; the purpose of the workshop was to discuss the generic geochemistry research needs for a nuclear waste repository among as broad spectrum of individual scientists as possible and to develop a consensus of what geochemical information is important and why.

  7. Socioeconomic studies of high-level nuclear waste disposal.

    PubMed Central

    White, G F; Bronzini, M S; Colglazier, E W; Dohrenwend, B; Erikson, K; Hansen, R; Kneese, A V; Moore, R; Page, E B; Rappaport, R A

    1994-01-01

    The socioeconomic investigations of possible impacts of the proposed repository for high-level nuclear waste at Yucca Mountain, Nevada, have been unprecedented in several respects. They bear on the public decision that sooner or later will be made as to where and how to dispose permanently of the waste presently at military weapons installations and that continues to accumulate at nuclear power stations. No final decision has yet been made. There is no clear precedent from other countries. The organization of state and federal studies is unique. The state studies involve more disciplines than any previous efforts. They have been carried out in parallel to federal studies and have pioneered in defining some problems and appropriate research methods. A recent annotated bibliography provides interested scientists with a compact guide to the 178 published reports, as well as to relevant journal articles and related documents. PMID:7971963

  8. Radiation and Thermal Ageing of Nuclear Waste Glass

    SciTech Connect

    Weber, William J

    2014-01-01

    The radioactive decay of fission products and actinides incorporated into nuclear waste glass leads to self-heating and self-radiation effects that may affect the stability, structure and performance of the glass in a closed system. Short-lived fission products cause significant self-heating for the first 600 years. Alpha decay of the actinides leads to self-radiation damage that can be significant after a few hundred years, and over the long time periods of geologic disposal, the accumulation of helium and radiation damage from alpha decay may lead to swelling, microstructural evolution and changes in mechanical properties. Four decades of research on the behavior of nuclear waste glass are reviewed.

  9. Supported liquid inorganic membranes for nuclear waste separation

    DOEpatents

    Bhave, Ramesh R; DeBusk, Melanie M; DelCul, Guillermo D; Delmau, Laetitia H; Narula, Chaitanya K

    2015-04-07

    A system and method for the extraction of americium from radioactive waste solutions. The method includes the transfer of highly oxidized americium from an acidic aqueous feed solution through an immobilized liquid membrane to an organic receiving solvent, for example tributyl phosphate. The immobilized liquid membrane includes porous support and separating layers loaded with tributyl phosphate. The extracted solution is subsequently stripped of americium and recycled at the immobilized liquid membrane as neat tributyl phosphate for the continuous extraction of americium. The sequestered americium can be used as a nuclear fuel, a nuclear fuel component or a radiation source, and the remaining constituent elements in the aqueous feed solution can be stored in glassified waste forms substantially free of americium.

  10. Nuclear Waste Glasses: Beautiful Simplicity of Complex Systems

    SciTech Connect

    Hrma, Pavel R.

    2009-01-01

    The behavior of glasses with a large number of components, such as waste glasses, is not more complex than the behavior of simple glasses. On the contrary, the presence of many components restricts the composition region of these glasses in a way that allows approximating composition-property relationships by linear functions. This has far-reaching practical consequences for formulating nuclear waste glasses. On the other hand, processing high-level and low-activity waste glasses presents various problems, such as crystallization, foaming, and salt segre-gation in the melter. The need to decrease the settling of solids in the melter to an acceptable level and to maximize the rate of melting presents major challenges to processing technology. However, the most important property of the glass product is its chemical durability, a somewhat vague concept in lieu of the assessment of the glass resistance to aqueous attack while the radioactivity decays over tens of thousands of years.

  11. Control of Nepheline Crystallization in Nuclear Waste Glass

    SciTech Connect

    Fox, Kevin

    2008-07-01

    Glass frits with a high B{sub 2}O{sub 3} concentration have been designed which, when combined with high-alumina concentration nuclear waste streams, will form glasses with durabilities that are acceptable for repository disposal and predictable using a free energy of hydration model. Two glasses with nepheline discriminator values closest to 0.62 showed significant differences in normalized boron release between the quenched and heat treated versions of each glass. X-ray diffraction confirmed that nepheline crystallized in the glass with the lowest nepheline discriminator value, and nepheline may also exist in the second glass as small nanocrystals. The high-B{sub 2}O{sub 3} frit was successful in producing simulated waste glasses with no detectable nepheline crystallization at waste loadings of up to 45 wt%. The melt rate of this frit was also considerably better than other frits with increased concentrations of Na{sub 2}O.

  12. Behavior of technetium in nuclear waste vitrification processes.

    PubMed

    Pegg, Ian L

    Nearly 100 tests were performed with prototypical melters and off-gas system components to investigate the extents to which technetium is incorporated into the glass melt, partitioned to the off-gas stream, and captured by the off-gas treatment system components during waste vitrification. The tests employed several simulants, spiked with (99m)Tc and Re (a potential surrogate), of the low activity waste separated from nuclear wastes in storage in the Hanford tanks, which is planned for immobilization in borosilicate glass. Single-pass technetium retention averaged about 35 % and increased significantly with recycle of the off-gas treatment fluids. The fraction escaping the recycle loop was very small.

  13. Americium and plutonium association with magnesium hydroxide colloids in alkaline nuclear industry process environments

    NASA Astrophysics Data System (ADS)

    Maher, Zoe; Ivanov, Peter; O'Brien, Luke; Sims, Howard; Taylor, Robin J.; Heath, Sarah L.; Livens, Francis R.; Goddard, David; Kellet, Simon; Rand, Peter; Bryan, Nick D.

    2016-01-01

    The behaviours of Pu, Am and colloids in feed solutions to the Site Ion-exchange Effluent Plant (SIXEP) at the Sellafield nuclear reprocessing site in the U.K. have been studied. For both Pu and Am, fractions were found to be associated with material in the colloidal size range, with ˜50% of the Pu in the range 1-200 nm. The concentration of soluble Pu (<1 nm) was ˜1 nM, which is very similar to the solubility limit for Pu(V). The soluble Am concentration was of the order of 10-11 M, which was below the solubility limit of americium hydroxide. The size, morphology and elemental composition of the particulates and colloids in the feed solutions were investigated. Magnesium is homogeneously distributed throughout the particles, whereas U, Si, Fe, and Ca were present in localised areas only. Amongst some heterogeneous material, particles were identified that were consistent with hydrotalcite. The distribution of 241Am(III) on brucite (magnesium hydroxide) colloids of different sizes was studied under alkaline conditions representative of nuclear fuel storage pond and effluent feed solution conditions. The morphology of the brucite particles in the bulk material observed by ESEM was predominantly hexagonal, while that of the carbonated brucite consisted of hexagonal species mixed with platelets. The association of 241Am(III) with the brucite colloids was studied by ultrafiltration coupled with gamma ray-spectrometry. For carbonate concentrations up to 10-3 M, the 241Am(III) was mainly associated with larger colloids (>300 kDa), and there was a shift from the smaller size fractions to the larger over a period of 6 months. At higher carbonate concentrations (10-2 M), the Am was predominantly detected in the true solution fraction (<3 kDa) and in smaller size colloidal fractions, in the range 3-100 kDa.

  14. Potential applications of nanostructured materials in nuclear waste management.

    SciTech Connect

    Braterman, Paul S. (The University of North Texas, Denton, TX); Phol, Phillip Isabio; Xu, Zhi-Ping (The University of North Texas, Denton, TX); Brinker, C. Jeffrey; Yang, Yi; Bryan, Charles R.; Yu, Kui; Xu, Huifang (University of New Mexico, Albuquerque, NM); Wang, Yifeng; Gao, Huizhen

    2003-09-01

    This report summarizes the results obtained from a Laboratory Directed Research & Development (LDRD) project entitled 'Investigation of Potential Applications of Self-Assembled Nanostructured Materials in Nuclear Waste Management'. The objectives of this project are to (1) provide a mechanistic understanding of the control of nanometer-scale structures on the ion sorption capability of materials and (2) develop appropriate engineering approaches to improving material properties based on such an understanding.

  15. Method of determining a content of a nuclear waste container

    DOEpatents

    Bernardi, Richard T.; Entwistle, David

    2003-04-22

    A method and apparatus are provided for identifying contents of a nuclear waste container. The method includes the steps of forming an image of the contents of the container using digital radiography, visually comparing contents of the image with expected contents of the container and performing computer tomography on the container when the visual inspection reveals an inconsistency between the contents of the image and the expected contents of the container.

  16. Framing ethical acceptability: a problem with nuclear waste in Canada.

    PubMed

    Wilding, Ethan T

    2012-06-01

    Ethical frameworks are often used in professional fields as a means of providing explicit ethical guidance for individuals and institutions when confronted with ethically important decisions. The notion of an ethical framework has received little critical attention, however, and the concept subsequently lends itself easily to misuse and ambiguous application. This is the case with the 'ethical framework' offered by Canada's Nuclear Waste Management Organization (NWMO), the crown-corporation which owns and is responsible for the long-term management of Canada's high-level nuclear fuel waste. It makes a very specific claim, namely that it is managing Canada's long-lived radioactive nuclear fuel waste in an ethically responsible manner. According to this organization, what it means to behave in an ethically responsible manner is to act and develop policy in accordance with its ethical framework. What, then, is its ethical framework, and can it be satisfied? In this paper I will show that the NWMO's ethical and social framework is deeply flawed in two respects: (a) it fails to meet the minimum requirements of a code of ethic or ethical framework by offering only questions, and no principles or rules of conduct; and (b) if posed as principles or rules of conduct, some of its questions are unsatisfiable. In particular, I will show that one of its claims, namely that it seek informed consent from individuals exposed to risk of harm from nuclear waste, cannot be satisfied as formulated. The result is that the NWMO's ethical framework is not, at present, ethically acceptable.

  17. Buying time: Franchising hazardous and nuclear waste cleanup

    SciTech Connect

    Hale, D.R.

    1997-05-01

    This paper describes a private franchise approach to long-term custodial care, monitoring and eventual cleanup of hazardous and nuclear waste sites. The franchise concept could be applied to Superfund sites, decommissioning commercial reactors and safeguarding their wastes and to Department of Energy sites. Privatization would reduce costs by enforcing efficient operations and capital investments during the containment period, by providing incentives for successful innovation and by sustaining containment until the cleanup`s net benefits exceed its costs. The franchise system would also permit local governments and citizens to demand and pay for more risk reduction than provided by the federal government. In principle, they would have the option of taking over site management. The major political drawback of the idea is that it requires society to be explicit about what it is willing to pay for now to protect current and future generations. Hazardous waste sites are enduring legacies of energy development. Abandoned mines, closed refineries, underground storage tanks and nuclear facilities have often become threats to human health and water quality. The policy of the United States government is that such sites should quickly be made nonpolluting and safe for unrestricted use. That is, the policy of the United States is prompt cleanup. Orphaned commercial hazardous waste sites are addressed by the US Environmental Protection Agency`s Superfund program. 17 refs., 2 tabs.

  18. Rheological characterization of nuclear waste using falling-ball rheometry

    SciTech Connect

    Abbott, J.R.; Unal, C.; Stephens, T.; Pasamehmetoglu, K.O.; Graham, A.L.; Edwards, J.N.

    1994-07-01

    Knowledge of the rheological properties of saturated solutions containing solid particles is very important in nuclear waste management technology. For example, the nuclear waste in the Hanford Site high-level radioactive waste tanks contains strong electrolyte solutions with a high concentration of solids. Previous attempt using rotational viscometers to determine the rheology has shown unusual thixotropic and shear thinning behaviors with a lack of reproducibility. Using falling-ball rheometry, the rheology of the undisturbed simulant may be determined with much better reproducibility. In this study, a well-mixed simulant which has similar chemical composition to the actual waste will be tested. Falling-ball size and density will be varied to get data in a wide range of shear rates. To determine the rheogram, several methods will be tried to match the observed data. Based on these tests, a rheogram can be determined from the model and its best-fit parameters. The simulant shows shear-thinning behavior and a yield stress. This would suggest a H-B model. But when fitting to one of the simulants which showed a very low yield stress, the predictions assuming no yield and assuming yield resulted in no improvement in the fit when assuming yield.

  19. Neural network analysis of nuclear waste glass composition vs durability

    SciTech Connect

    Seibel, C.K.

    1994-04-01

    The relationship between the chemical composition of oxide glasses and their physical properties is poorly understood, but it is becoming more important as vitrification (transformation into glass) of high-level nuclear waste becomes the favored method for long-term storage. The vitrified waste will be stored deep in geologic repositories where it must remain intact for at least 10,000 years. A strong resistance to groundwater exposure; i.c. a slow rate of glass dissolution, is of great importance. This project deals specifically with glass samples developed and tested for the nuclear fuel reprocessing facility near West Valley, New York. This facility needs to dispose of approximately 2.2 million liters of high-level radioactive liquid waste currently stored in stainless steel tanks. A self-organizing, artificial neural network was used to analyze the trends in the glass dissolution data for the effects of composition and the resulting durability of borosilicate glasses in an aqueous environment. This durability data can be used to systematically optimize the properties of the complex nuclear glasses and slow the dissolution rate of radionuclides into the environment.

  20. Nuclear Waste Analytical Round Robins 1-6 summary report

    SciTech Connect

    Smith, G.L.; Marschman, S.C.

    1993-12-31

    The MCC has conducted six round robins for the waste management, research, and development community from 1987 to present. The laboratories participating regularly are Ames, Argonne, Catholic University, Lawrence Livermore, Pacific Northwest Laboratory, Savannah River, and West Valley Nuclear. Glass types analyzed in these round robins all have been simulated nuclear waste compositions expected from vitrification of high-level nuclear waste. A wide range of analytical procedures have been used by the participating laboratories including Atomic Absorption spectroscopy, inductively coupled plasma-atomic emission spectroscopy, direct current plasma-emission spectroscopy, and inductively coupled plasma-mass spectroscopy techniques. Consensus average relative error for Round Robins 1 through 6 is 5.4%, with values ranging from 9.4 to 1.1%. Trend on the average improved with each round robin. When the laboratories analyzed samples over longer periods of time, the intralaboratory variability increased. Lab-to-lab variation accounts for most of the total variability found in all the round robins. Participation in the radiochemistry portion has been minimal, and analytical results poor compared to nonradiochemistry portion. Additional radiochemical work is needed in future round robins.

  1. Preliminary risk benefit assessment for nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Denning, R. S.; Friedlander, A. L.; Priest, C. C.

    1982-01-01

    This paper describes the recent work of the authors on the evaluation of health risk benefits of space disposal of nuclear waste. The paper describes a risk model approach that has been developed to estimate the non-recoverable, cumulative, expected radionuclide release to the earth's biosphere for different options of nuclear waste disposal in space. Risk estimates for the disposal of nuclear waste in a mined geologic repository and the short- and long-term risk estimates for space disposal were developed. The results showed that the preliminary estimates of space disposal risks are low, even with the estimated uncertainty bounds. If calculated release risks for mined geologic repositories remain as low as given by the U.S. DOE, and U.S. EPA requirements continue to be met, then no additional space disposal study effort in the U.S. is warranted at this time. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as a complement to the mined geologic repository is warranted.

  2. Preliminary risk benefit assessment for nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Denning, R. S.; Friedlander, A. L.; Priest, C. C.

    1982-01-01

    This paper describes the recent work of the authors on the evaluation of health risk benefits of space disposal of nuclear waste. The paper describes a risk model approach that has been developed to estimate the non-recoverable, cumulative, expected radionuclide release to the earth's biosphere for different options of nuclear waste disposal in space. Risk estimates for the disposal of nuclear waste in a mined geologic repository and the short- and long-term risk estimates for space disposal were developed. The results showed that the preliminary estimates of space disposal risks are low, even with the estimated uncertainty bounds. If calculated release risks for mined geologic repositories remain as low as given by the U.S. DOE, and U.S. EPA requirements continue to be met, then no additional space disposal study effort in the U.S. is warranted at this time. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as a complement to the mined geologic repository is warranted.

  3. The Storage, Transportation, and Disposal of Nuclear Waste

    NASA Astrophysics Data System (ADS)

    Younker, J. L.

    2002-12-01

    The U.S. Congress established a comprehensive federal policy to dispose of wastes from nuclear reactors and defense facilities, centered on deep geologic disposal of high-level radioactive waste. Site screening led to selection of three potential sites and in 1987, Congress directed the Secretary of Energy to characterize only one site: Yucca Mountain in Nevada. For more than 20 years, teams of scientists and engineers have been evaluating the potential suitability of the site. On the basis of their work, the U.S. Secretary of Energy, Spencer Abraham, concluded in February 2002 that a safe repository can be sited at Yucca Mountain. On July 23, 2002, President Bush signed Joint Resolution 87 approving the site at Yucca Mountain for development of a repository, which allows the U.S. Department of Energy (DOE) to prepare and submit a license application to the U.S. Nuclear Regulatory Commission (NRC). Concerns have been raised relative to the safe transportation of nuclear materials. The U.S. history of transportation of nuclear materials demonstrates that high-level nuclear materials can be safely transported. Since the 1960s, over 1.6 million miles have been traveled by more than 2,700 spent nuclear fuel shipments, and there has never been an accident severe enough to cause a release of radioactive materials. The DOE will use NRC-certified casks that must be able to withstand very stringent tests. The same design features that allow the casks to survive severe accidents also limit their vulnerability to sabotage. In addition, the NRC will approve all shipping routes and security plans. With regard to long-term safety, the Yucca Mountain disposal system has five key attributes. First, the arid climate and geology of Yucca Mountain combine to ensure that limited water will enter the emplacement tunnels. Second, the DOE has designed a waste package and drip shield that are expected to have very long lifetimes in the repository environment. Third, waste form

  4. Nuclear waste repository transparency technology test bed demonstrations at WIPP

    SciTech Connect

    BETSILL,J. DAVID; ELKINS,NED Z.; WU,CHUAN-FU; MEWHINNEY,JAMES D.; AAMODT,PAUL

    2000-01-27

    Secretary of Energy, Bill Richardson, has stated that one of the nuclear waste legacy issues is ``The challenge of managing the fuel cycle's back end and assuring the safe use of nuclear power.'' Waste management (i.e., the back end) is a domestic and international issue that must be addressed. A key tool in gaining acceptance of nuclear waste repository technologies is transparency. Transparency provides information to outside parties for independent assessment of safety, security, and legitimate use of materials. Transparency is a combination of technologies and processes that apply to all elements of the development, operation, and closure of a repository system. A test bed for nuclear repository transparency technologies has been proposed to develop a broad-based set of concepts and strategies for transparency monitoring of nuclear materials at the back end of the fuel/weapons cycle. WIPP is the world's first complete geologic repository system for nuclear materials at the back end of the cycle. While it is understood that WIPP does not currently require this type of transparency, this repository has been proposed as realistic demonstration site to generate and test ideas, methods, and technologies about what transparency may entail at the back end of the nuclear materials cycle, and which could be applicable to other international repository developments. An integrated set of transparency demonstrations was developed and deployed during the summer, and fall of 1999 as a proof-of-concept of the repository transparency technology concept. These demonstrations also provided valuable experience and insight into the implementation of future transparency technology development and application. These demonstrations included: Container Monitoring Rocky Flats to WIPP; Underground Container Monitoring; Real-Time Radiation and Environmental Monitoring; Integrated level of confidence in the system and information provided. As the world's only operating deep geologic

  5. Performance of Nondestructive Radioassay Systems for Nuclear Waste

    SciTech Connect

    Blackwood, Larry G.; Meachum, Teresa R.; Becker, Gregory K.

    2004-01-01

    A statistical analysis of the measurement performance of five mobile nondestructive assay systems currently in use for radioassay of nuclear waste was performed. Actual versus reported isotopic mass composition, reported versus actual measurement uncertainty, detection capability, and low level versus transuranic waste determination were assessed based on measurements of 11 surrogate waste drums. In terms of percent recovery the systems, for the most part, exhibited reasonable capabilities for estimating isotopic quantities in the surrogate waste drums. (By reasonable we mean, for example, that recovery values were in a range of 40% to 160% for most of the configurations tested.) While difference in performance on individual drums was quite large in some cases, nonparametric analysis of variance results for total plutonium and 241Am showed no statistically significant differences in the overall average percent recovery values for the systems evaluated. A similar analysis of the replicate standard deviations indicated significant differences between systems with regard to precision of measurements of total plutonium but not 241Am. The weakest aspect of system performance was the reporting of measurement errors. Reported measurement error values routinely underestimated actual values for certain surrogate waste configurations.

  6. Review of concrete biodeterioration in relation to nuclear waste.

    PubMed

    Turick, Charles E; Berry, Christopher J

    2016-01-01

    Storage of radioactive waste in concrete structures is a means of containing wastes and related radionuclides generated from nuclear operations in many countries. Previous efforts related to microbial impacts on concrete structures that are used to contain radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete structures used to store or dispose of radioactive waste. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources such as components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The microbial contribution to degradation of the concrete structures containing radioactive waste is a constant possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Parameters to focus on for modeling activities and possible options for mitigation that would minimize concrete biodegradation are discussed and include key conditions that drive microbial activity on concrete surfaces.

  7. Corrosion of steel in simulated nuclear waste solutions

    SciTech Connect

    Mickalonis, J.I.

    1993-12-01

    Processing of inhibited nuclear waste to forms for long-term storage will cause waste tank environments to have dynamic conditions. During processing compositional changes in the waste may produce a corrosive environment for the plain carbon steel tanks. Large concentrations of nitrates which corrode steel are contained in the waste. Nitrite and hydroxides are added to inhibit any corrosion. Concentration changes of nitrate and nitrite were investigated to identify corrosion regimes that may occur during processing. Corrosion testing was performed with cyclic potentiodynamic polarization and linear polarization resistance. Test samples were plain carbon steel which was similar to the material of construction of the waste tanks. The corrosion morphology of test samples was investigated by visual evaluation and scanning electron microscopy. Qualitative chemical analysis was also performed using energy dispersive spectroscopy. The corrosion mechanism changed as a function of the nitrate concentration. As the nitrate concentration was increased the steel transitioned from a passive state to general attack, and finally pitting and crevice corrosion. The nitrate anion appeared to destabilize the surface oxide. Nitrite countered the oxide breakdown, although the exact mechanism was not determined.

  8. Yucca Mountain nuclear waste repository prompts heated congressional hearing

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-11-01

    Although the final report of the Blue Ribbon Commission on America's Nuclear Future is not expected until January 2012, the tentative conclusions of the commission's draft report were dissected during a recent joint hearing by two subcommittees of the House of Representatives' Committee on Science, Space, and Technology. Among the more heated issues debated at the hearing was the fate of the stalled Yucca Mountain nuclear waste repository in Nevada. The Blue Ribbon Commission's (BRC) draft report includes recommendations for managing nuclear waste and for developing one or more permanent deep geological repositories and interim storage facilities, but the report does not address the future of Yucca Mountain. The BRC charter indicates that the commission is to "conduct a comprehensive review of policies for managing the back end of the nuclear fuel cycle." However, the draft report states that the commission was not asked to consider, and therefore did not address, several key issues. "We have not rendered an opinion on the suitability of the Yucca Mountain site or on the request to withdraw the license application for Yucca Mountain," the draft report states.

  9. Local acceptance of a high-level nuclear waste repository.

    PubMed

    Sjöberg, Lennart

    2004-06-01

    The siting of nuclear waste facilities has been very difficult in all countries. Recent experience in Sweden indicates, however, that it may be possible, under certain circumstances, to gain local support for the siting of a high-level nuclear waste (HLNW) repository. The article reports on a study of attitudes and risk perceptions of people living in four municipalities in Sweden where HLNW siting was being intensely discussed at the political level, in media, and among the public. Data showed a relatively high level of consensus on acceptability of at least further investigation of the issue; in two cases local councils have since voted in favor of a go-ahead, and in one case only a very small majority defeated the issue. Models of policy attitudes showed that these were related to attitude to nuclear power, attributes of the perceived HLNW risk, and trust. Factors responsible for acceptance are discussed at several levels. One is the attitude to nuclear power, which is becoming more positive, probably because no viable alternatives are in sight. Other factors have to do with the extensive information programs conducted in these municipalities, and with the logical nature of the conclusion that they would be good candidates for hosting the national HLNW repository.

  10. HEAT TRANSFER ANALYSIS FOR NUCLEAR WASTE SOLIDIFICATION CONTAINER

    SciTech Connect

    Lee, S.

    2009-06-01

    The Nuclear Nonproliferation Programs Design Authority is in the design stage of the Waste Solidification Building (WSB) for the treatment and solidification of the radioactive liquid waste streams generated by the Pit Disassembly and Conversion Facility (PDCF) and Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The waste streams will be mixed with a cementitious dry mix in a 55-gallon waste container. Savannah River National Laboratory (SRNL) has been performing the testing and evaluations to support technical decisions for the WSB. Engineering Modeling & Simulation Group was requested to evaluate the thermal performance of the 55-gallon drum containing hydration heat source associated with the current baseline cement waste form. A transient axi-symmetric heat transfer model for the drum partially filled with waste form cement has been developed and heat transfer calculations performed for the baseline design configurations. For this case, 65 percent of the drum volume was assumed to be filled with the waste form, which has transient hydration heat source, as one of the baseline conditions. A series of modeling calculations has been performed using a computational heat transfer approach. The baseline modeling results show that the time to reach the maximum temperature of the 65 percent filled drum is about 32 hours when a 43 C initial cement temperature is assumed to be cooled by natural convection with 27 C external air. In addition, the results computed by the present model were compared with analytical solutions. The modeling results will be benchmarked against the prototypic test results. The verified model will be used for the evaluation of the thermal performance for the WSB drum. Detailed results and the cases considered in the calculations will be discussed here.

  11. Review of Concrete Biodeterioration in Relation to Buried Nuclear Waste

    SciTech Connect

    Turick, C; Berry, C.

    2012-10-15

    Long-term storage of low level radioactive material in below ground concrete disposal units (DUs) (Saltstone Disposal Facility) is a means of depositing wastes generated from nuclear operations of the U.S. Department of Energy. Based on the currently modeled degradation mechanisms, possible microbial induced effects on the structural integrity of buried low level wastes must be addressed. Previous international efforts related to microbial impacts on concrete structures that house low level radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the recent research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete vaults housing stored wastes and the wastes themselves. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources like components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The results of this review suggest that microbial activity in Saltstone, (grouted low level radioactive waste) is unlikely due to very high pH and osmotic pressure. Biodegradation of the concrete vaults housing the radioactive waste however, is a possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Results from this review point to parameters to focus on for modeling activities and also, possible options for mitigation that would minimize concrete biodegradation. In addition, key chemical components that drive microbial

  12. Nuclear Waste Management - A Need to Ensure that the Waste Decays While the Knowledge Does Not

    SciTech Connect

    Biedscheid, J.; Devarakonda, M.

    2006-07-01

    The unique time scales associated with nuclear waste management require active work to preserve the knowledge associated with programs that can often span long time frames. For example, repository programs are designed and developed for the safe containment of radionuclides with half-lives on the order of 24,000 years (for Pu-239). Performance assessment studies are required to show, by predictive modeling, that these repositories can safely contain the waste for tens of thousands of years, with one million years a reality in the debate. Development of successful repository programs can span several decades. Once operational, a repository is expected to function until closure for a period of 30 to 40 years. Yet, the decision makers at all levels in such a repository program exert influence and authority over much shorter periods of time (e.g., four years for executive appointments). A discontinuous decision-making process and the associated potential for loss of critical program knowledge are challenges that nuclear waste management programs face in various countries. Due to the disparity of the time frames for the project and associated decision-making, a proactive program to preserve original and developing knowledge for technical and programmatic decisions is vital to the success of any nuclear waste management program. While the mechanisms for knowledge preservation may be program specific, the need for programs to acknowledge and implement a methodology for maintaining program intelligence is collectively shared. (authors)

  13. Consideration of nuclear criticality when disposing of transuranic waste at the Waste Isolation Pilot Plant

    SciTech Connect

    RECHARD,ROBERT P.; SANCHEZ,LAWRENCE C.; STOCKMAN,CHRISTINE T.; TRELLUE,HOLLY R.

    2000-04-01

    Based on general arguments presented in this report, nuclear criticality was eliminated from performance assessment calculations for the Waste Isolation Pilot Plant (WIPP), a repository for waste contaminated with transuranic (TRU) radioisotopes, located in southeastern New Mexico. At the WIPP, the probability of criticality within the repository is low because mechanisms to concentrate the fissile radioisotopes dispersed throughout the waste are absent. In addition, following an inadvertent human intrusion into the repository (an event that must be considered because of safety regulations), the probability of nuclear criticality away from the repository is low because (1) the amount of fissile mass transported over 10,000 yr is predicted to be small, (2) often there are insufficient spaces in the advective pore space (e.g., macroscopic fractures) to provide sufficient thickness for precipitation of fissile material, and (3) there is no credible mechanism to counteract the natural tendency of the material to disperse during transport and instead concentrate fissile material in a small enough volume for it to form a critical concentration. Furthermore, before a criticality would have the potential to affect human health after closure of the repository--assuming that a criticality could occur--it would have to either (1) degrade the ability of the disposal system to contain nuclear waste or (2) produce significantly more radioisotopes than originally present. Neither of these situations can occur at the WIPP; thus, the consequences of a criticality are also low.

  14. Colloid formation during waste form reaction: implications for nuclear waste disposal

    USGS Publications Warehouse

    Bates, J. K.; Bradley, J.; Teetsov, A.; Bradley, C. R.; ten Brink, Marilyn Buchholtz

    1992-01-01

    Insoluble plutonium- and americium-bearing colloidal particles formed during simulated weathering of a high-level nuclear waste glass. Nearly 100 percent of the total plutonium and americium in test ground water was concentrated in these submicrometer particles. These results indicate that models of actinide mobility and repository integrity, which assume complete solubility of actinides in ground water, underestimate the potential for radionuclide release into the environment. A colloid-trapping mechanism may be necessary for a waste repository to meet long-term performance specifications.

  15. Colloid formation during waste form reaction: Implications for nuclear waste disposal

    USGS Publications Warehouse

    Bates, J. K.; Bradley, J.; Teetsov, A.; Bradley, C. R.; ten Brink, Marilyn Buchholtz

    1992-01-01

    Insoluble plutonium- and americium-bearing colloidal particles formed during simulated weathering of a high-level nuclear waste glass. Nearly 100 percent of the total plutonium and americium in test ground water was concentrated in these submicrometer particles. These results indicate that models of actinide mobility and repository integrity, which assume complete solubility of actinides in ground water, underestimate the potential for radionuclide release into the environment. A colloid-trapping mechanism may be necessary for a waste repository to meet long-term performance specifications.

  16. Two citizen task forces and the challenge of the evolving nuclear waste siting process

    SciTech Connect

    Peelle, E.B.

    1990-01-01

    Siting any nuclear waste facility is problematic in today's climate of distrust toward nuclear agencies and fear of nuclear waste. This study compares and contrasts the siting and public participation processes as two citizen task forces dealt with their difficult responsibilities. 10 refs., 3 tabs.

  17. Processing of historic high radioactive waste coming from nuclear applications

    SciTech Connect

    Van Velzen, L.P.M.; Vos, R.M. de; Roobol, L.P.; IJpelaan, R.; Van Tongeren, R.

    2007-07-01

    At ECN-NRG irradiations of materials have been performed with the aid of the High Flux Reactor at the site for investigations of their properties under different conditions as well for nuclear isotope productions since 1967 e.g. molybdenum. The high radioactive waste (HRW) coming from these nuclear applications are stored since the start in an interim storage facility located at the site. Due to the site license the HRW has to be transported to COVRA. Therefore a project has been set-up to transport all the HRW to COVRA. However, COVRA accepts a limited number of HLW containers among the CASTOR{sup R} MTR-2 container and thus all temporary stored drums have to be over packed. As the existing infra structure at the site is not suited a new facility has to be build. This also creates the opportunity to minimize, by separation of the HRW in low- and intermediate level waste, the amount of waste that has to be classified as HLW. The applied methodology, design and specifications of the HRW-ILW non-destructive assay characterization and separation system will be described. (authors)

  18. Nuclear microprobe applications to radioactive waste management basic research

    NASA Astrophysics Data System (ADS)

    Trocellier, P.; Badillo, V.; Barré, N.; Bois, L.; Cachoir, C.; Gallien, J. P.; Guilbert, S.; Mercier, F.; Tiffreau, C.

    1999-10-01

    Radioactive waste management is one of the major technical and scientific challenge to be solved by industrialized countries near the beginning of the 21st century. Relevant questions arise about the extrapolation of the long term-behavior of materials from waste package, engineered barriers and near field repository. Whatever the strategical option might be, wet atmosphere or water intrusion through the different barriers constitute the two main remobilization factors for radionuclides in the geosphere and the biosphere. The study of solid alteration processes and elemental sorption phenomena on mineral surfaces is one of the most efficient basic research approaches to assess the long term performance of waste materials. Ion beam analysis and more recently nuclear microprobe techniques have been applied to investigate exchange mechanisms near representative solid/liquid interfaces such as glass/deionized water, uranium dioxide/granitic or clay water or mineral surface/aqueous solution doped with chemical elements analogue to actinide or fission products. This paper intends to describe the different works that have been carried out in Saclay using the nuclear microprobe facility. The coupling of μRBS, μPIXE and μNRA permits to determine the evolution of the surface composition induced by chemical reactions involved. Complementary observation of solid morphology and solution analysis allows to obtain a complete elemental balance on exchange processes.

  19. Preliminary drift design analyses for nuclear waste repository in tuff

    SciTech Connect

    Hardy, M.P.; Brechtel, C.E.; Goodrich, R.R.; Bauer, S.J.

    1990-01-30

    The Yucca Mountain Project (YMP) is examining the feasibility of siting a repository for high-level nuclear waste at Yucca Mountain, on and adjacent to the Nevada Test Site (NTS). The proposed repository will be excavated in the Topopah Spring Member, which is a moderately fractured, unsaturated, welded tuff. Excavation stability will be required during construction, waste emplacement, retrieval (if required), and closure to ensure worker safety. The subsurface excavations will be subject to stress changes resulting from thermal expansion of the rock mass and seismic events associated with regional tectonic activity and underground nuclear explosions (UNEs). Analyses of drift stability are required to assess the acceptable waste emplacement density, to design the drift shapes and ground support systems, and to establish schedules and cost of construction. This paper outlines the proposed methodology to assess drift stability and then focuses on an example of its application to the YMP repository drifts based on preliminary site data. Because site characterization activities have not begun, the database currently lacks the extensive site-specific field and laboratory data needed to form conclusions as to the final ground support requirements. This drift design methodology will be applied and refined as more site-specific data are generated and as analytical techniques and methodologies are verified during the site characterization process.

  20. Application of gaseous core reactors for transmutation of nuclear waste

    NASA Technical Reports Server (NTRS)

    Schnitzler, B. G.; Paternoster, R. R.; Schneider, R. T.

    1976-01-01

    An acceptable management scheme for high-level radioactive waste is vital to the nuclear industry. The hazard potential of the trans-uranic actinides and of key fission products is high due to their nuclear activity and/or chemical toxicity. Of particular concern are the very long-lived nuclides whose hazard potential remains high for hundreds of thousands of years. Neutron induced transmutation offers a promising technique for the treatment of problem wastes. Transmutation is unique as a waste management scheme in that it offers the potential for "destruction" of the hazardous nuclides by conversion to non-hazardous or more manageable nuclides. The transmutation potential of a thermal spectrum uranium hexafluoride fueled cavity reactor was examined. Initial studies focused on a heavy water moderated cavity reactor fueled with 5% enriched U-235-F6 and operating with an average thermal flux of 6 times 10 to the 14th power neutrons/sq cm-sec. The isotopes considered for transmutation were I-129, Am-241, Am-242m, Am-243, Cm-243, Cm-244, Cm-245, and Cm-246.

  1. Application of gaseous core reactors for transmutation of nuclear waste

    NASA Technical Reports Server (NTRS)

    Schnitzler, B. G.; Paternoster, R. R.; Schneider, R. T.

    1976-01-01

    An acceptable management scheme for high-level radioactive waste is vital to the nuclear industry. The hazard potential of the trans-uranic actinides and of key fission products is high due to their nuclear activity and/or chemical toxicity. Of particular concern are the very long-lived nuclides whose hazard potential remains high for hundreds of thousands of years. Neutron induced transmutation offers a promising technique for the treatment of problem wastes. Transmutation is unique as a waste management scheme in that it offers the potential for "destruction" of the hazardous nuclides by conversion to non-hazardous or more manageable nuclides. The transmutation potential of a thermal spectrum uranium hexafluoride fueled cavity reactor was examined. Initial studies focused on a heavy water moderated cavity reactor fueled with 5% enriched U-235-F6 and operating with an average thermal flux of 6 times 10 to the 14th power neutrons/sq cm-sec. The isotopes considered for transmutation were I-129, Am-241, Am-242m, Am-243, Cm-243, Cm-244, Cm-245, and Cm-246.

  2. Americium/Lanthanide Separations in Alkaline Solutions for Advanced Nuclear Fuel Cycles

    SciTech Connect

    Goff, George S.; Long, Kristy Marie; Reilly, Sean D.; Jarvinen, Gordon D.; Runde, Wolfgang H.

    2012-06-11

    Project goals: Can used nuclear fuel be partitioned by dissolution in alkaline aqueous solution to give a solution of uranium, neptunium, plutonium, americium and curium and a filterable solid containing nearly all of the lanthanide fission products and certain other fission products? What is the chemistry of Am/Cm/Ln in oxidative carbonate solutions? Can higher oxidation states of Am be stabilized and exploited? Conclusions: Am(VI) is kinetically stable in 0.5-2.0 M carbonate solutions for hours. Aliquat 336 in toluene has been successfully shown to extract U(VI) and Pu(VI) from carbonate solutions. (Stepanov et al 2011). Higher carbonate concentration gives lower D, SF{sub U/Eu} for = 4 in 1 M K{sub 2}CO{sub 3}. Experiments with Am(VI) were unsuccessful due to reduction by the organics. Multiple sources of reducing organics...more optimization. Reduction experiments of Am(VI) in dodecane/octanol/Aliquat 336 show that after 5 minutes of contact, only 30-40% of the Am(VI) has been reduced. Long enough to perform an extraction. Shorter contact times, lower T, and lower Aliquat 336 concentration still did not result in any significant extraction of Am. Anion exchange experiments using a strong base anion exchanger show uptake of U(VI) with minimal uptake of Nd(III). Experiments with Am(VI) indicate Am sorption with a Kd of 9 (10 minute contact) but sorption mechanism is not yet understood. SF{sub U/Nd} for = 7 and SF{sub U/Eu} for = 19 after 24 hours in 1 M K{sub 2}CO{sub 3}.

  3. Solid-phase zirconium and fluoride species in alkaline zircaloy cladding waste at Hanford.

    PubMed

    Reynolds, Jacob G; Huber, Heinz J; Cooke, Gary A; Pestovich, John A

    2014-08-15

    The United States Department of Energy Hanford Site, near Richland, Washington, USA, processed plutonium between 1944 and 1987. Fifty-six million gallons of waste of various origins remain, including waste from removing zircaloy fuel cladding using the so-called Zirflex process. The speciation of zirconium and fluoride in this waste is important because of the corrosivity and reactivity of fluoride as well as the (potentially) high density of Zr-phases. This study evaluates the solid-phase speciation of zirconium and fluoride using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). Two waste samples were analyzed: one waste sample that is relatively pure zirconium cladding waste from tank 241-AW-105 and another that is a blend of zirconium cladding wastes and other high-level wastes from tank 241-C-104. Villiaumite (NaF) was found to be the dominant fluoride species in the cladding waste and natrophosphate (Na7F[PO4]2 · 19H2O) was the dominant species in the blended waste. Most zirconium was present as a sub-micron amorphous Na-Zr-O phase in the cladding waste and a Na-Al-Zr-O phase in the blended waste. Some zirconium was present in both tanks as either rounded or elongated crystalline needles of Na-bearing ZrO2 that are up to 200 μm in length. These results provide waste process planners the speciation data needed to develop disposal processes for this waste.

  4. Seismic design of low-level nuclear waste repositories and toxic waste management facilities

    SciTech Connect

    Chung, D.H.; Bernreuter, D.L.

    1984-05-08

    Identification of the elements of typical hazardous waste facilities (HFWs) that are the major contributors to the risk are focussed on as the elements which require additional considerations in the design and construction of low-level nuclear waste management repositories and HWFs. From a recent study of six typical HWFs it was determined that the factors that contribute most to the human and environmental risk fall into four basic categories: geologic and seismological conditions at each HWF; engineered structures at each HWF; environmental conditions at each HWF; and nature of the material being released. In selecting and carrying out the six case studies, three groups of hazardous waste facilities were examined: generator industries which treat or temporarily store their own wastes; generator facilities which dispose of their own hazardous wastes on site; and industries in the waste treatment and disposal business. The case studies have a diversity of geologic setting, nearby settlement patterns, and environments. Two sites are above a regional aquifer, two are near a bay important to regional fishing, one is in rural hills, and one is in a desert, although not isolated from nearby towns and a groundwater/surface-water system. From the results developed in the study, it was concluded that the effect of seismic activity on hazardous facilities poses a significant risk to the population. Fifteen reasons are given for this conclusion.

  5. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

    SciTech Connect

    Schultz, Peter Andrew

    2011-12-01

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

  6. Health Cost of a Nuclear Waste Repository, WIPP

    NASA Astrophysics Data System (ADS)

    Kula, Erhun

    1996-01-01

    The Waste Isolation Pilot Plant (WIPP), the United States of America’s first nuclear waste dumping site, has over the years generated a great deal of concern and controversy. The most sensitive aspect of this project is that it may impose serious health risks on future generations. The first leg of this project is about to be completed and at the time of writing the Department of Energy is planning to perform experiments with a small quantity of waste for operational demonstrations. If everything goes well, then towards the end of this decade large quantities of wastes will be transported to the site for disposal. This article reconsiders the health cost of this project from an economic perspective in light of recent developments in the field of social discounting. As in earlier studies, two cases of health risks are considered: total cancer and genetic deformity over a one million year cutoff period. The analysis shows that whereas ordinary discounting method wipes out the future health detriments, expressed in monetary terms, the modified discounting criterion retains a substantial proportion of such costs in economic analysis.

  7. State of Nevada, Agency for Nuclear Projects/Nuclear Waste Project Office narrative report, January 1--June 30, 1991

    SciTech Connect

    1996-08-01

    The Agency for Nuclear Projects/Nuclear Waste Project Office (NWPO) is the State of Nevada agency designated by State law to monitor and oversee US Department of Energy (DOE) activities relative to the possible siting, construction, operation and closure of a high-level nuclear waste repository at Yucca Mountain and to carry out the State of Nevada`s responsibilities under the Nuclear Waste Policy Act of 1982. During the reporting period the NWPO continued to work toward the five objectives designed to implement the Agency`s oversight responsibilities. (1) Assure that the health and safety of Nevada`s citizens are adequately protected with regard to any federal high-level radioactive waste program within the State. (2) Take the responsibilities and perform the duties of the State of Nevada as described in the Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the Nuclear Waste Policy Amendments Act of 1987. (3) Advise the Governor, the State Commission on Nuclear Projects and the Nevada State Legislature on matters concerning the potential disposal of high-level radioactive waste in the State. (4) Work closely and consult with affected local governments and State agencies. (5) Monitor and evaluate federal planning and activities regarding high-level radioactive waste disposal. Plan and conduct independent State studies regarding the proposed repository.

  8. Convective instabilities in liquid centrifugation for nuclear wastes separation

    SciTech Connect

    Camassa, R.

    1995-10-01

    The separation of fission products from liquid solutions using centrifugal forces may prove an effective alternative to chemical processing in cases where radioactive materials necessitate minimal mixed-waste products or when allowing access to sophisticated chemical processing is undesirable. This investigation is a part of the effort to establish the feasibility of using liquid centrifugation for nuclear waste separation in the Accelerator Driven Energy Production (ADEP) program. A number of fundatmental issues in liquid centrifugation with radioactive elements need to be addressed in order to validate the approach and provide design criteria for experimental liquid salt (LiF and BeF{sub 2}) centrifuge. The author concentrates on one such issue, the possible onset of convective instabilities which could inhibit separation.

  9. National briefing summaries: Nuclear fuel cycle and waste management

    SciTech Connect

    Schneider, K.J.; Lakey, L.T.; Silviera, D.J.

    1988-12-01

    The National Briefing Summaries is a compilation of publicly available information concerning the nuclear fuel cycle and radioactive waste management strategies and programs of 21 nations, including the United States and three international agencies that have publicized their activities in this field. It presents available highlight information with references that may be used by the reader for additional information. The information in this document is compiled primarily for use by the US Department of Energy and other US federal agencies and their contractors to provide summary information on radioactive waste management activities in other countries. This document provides an awareness to managers and technical staff of what is occurring in other countries with regard to strategies, activities, and facilities. The information may be useful in program planning to improve and benefit United States' programs through foreign information exchange. Benefits to foreign exchange may be derived through a number of exchange activities.

  10. Volatile Fatty Acids Production from Codigestion of Food Waste and Sewage Sludge Based on β-Cyclodextrins and Alkaline Treatments.

    PubMed

    Yang, Xue; Liu, Xiang; Chen, Si; Liu, Guangmin; Wu, Shuyan; Wan, Chunli

    2016-01-01

    Volatile fatty acids (VFAs) are preferred valuable resources, which can be produced from anaerobic digestion process. This study presents a novel technology using β-cyclodextrins (β-CD) pretreatment integrated alkaline method to enhance VFAs production from codigestion of food waste and sewage sludge. Experiment results showed that optimized ratio of food waste to sewage sludge was 3 : 2 because it provided adequate organic substance and seed microorganisms. Based on this optimized ratio, the integrated treatment of alkaline pH 10 and β-CD addition (0.2 g/g TS) performed the best enhancement on VFAs production, and the maximum VFAs production was 8631.7 mg/L which was 6.13, 1.38, and 1.57 times higher than that of control, initial pH 10, and 0.2 g β-CD/g TS treatment, respectively. Furthermore, the hydrolysis rate of protein and polysaccharides was greatly improved in integration treatment, which was 1.18-3.45 times higher than that of other tests. Though the VFAs production and hydrolysis of polymeric organics were highly enhanced, the primary bacterial communities with different treatments did not show substantial differences.

  11. Volatile Fatty Acids Production from Codigestion of Food Waste and Sewage Sludge Based on β-Cyclodextrins and Alkaline Treatments

    PubMed Central

    Yang, Xue; Liu, Xiang; Chen, Si; Wu, Shuyan

    2016-01-01

    Volatile fatty acids (VFAs) are preferred valuable resources, which can be produced from anaerobic digestion process. This study presents a novel technology using β-cyclodextrins (β-CD) pretreatment integrated alkaline method to enhance VFAs production from codigestion of food waste and sewage sludge. Experiment results showed that optimized ratio of food waste to sewage sludge was 3 : 2 because it provided adequate organic substance and seed microorganisms. Based on this optimized ratio, the integrated treatment of alkaline pH 10 and β-CD addition (0.2 g/g TS) performed the best enhancement on VFAs production, and the maximum VFAs production was 8631.7 mg/L which was 6.13, 1.38, and 1.57 times higher than that of control, initial pH 10, and 0.2 g β-CD/g TS treatment, respectively. Furthermore, the hydrolysis rate of protein and polysaccharides was greatly improved in integration treatment, which was 1.18–3.45 times higher than that of other tests. Though the VFAs production and hydrolysis of polymeric organics were highly enhanced, the primary bacterial communities with different treatments did not show substantial differences. PMID:28096735

  12. Microbial impacts on (99m)Tc migration through sandstone under highly alkaline conditions relevant to radioactive waste disposal.

    PubMed

    Smith, Sarah L; Boothman, Christopher; Williams, Heather A; Ellis, Beverly L; Wragg, Joanna; West, Julia M; Lloyd, Jonathan R

    2017-01-01

    Geological disposal of intermediate level radioactive waste in the UK is planned to involve the use of cementitious materials, facilitating the formation of an alkali-disturbed zone within the host rock. The biogeochemical processes that will occur in this environment, and the extent to which they will impact on radionuclide migration, are currently poorly understood. This study investigates the impact of biogeochemical processes on the mobility of the radionuclide technetium, in column experiments designed to be representative of aspects of the alkali-disturbed zone. Results indicate that microbial processes were capable of inhibiting (99m)Tc migration through columns, and X-ray radiography demonstrated that extensive physical changes had occurred to the material within columns where microbiological activity had been stimulated. The utilisation of organic acids under highly alkaline conditions, generating H2 and CO2, may represent a mechanism by which microbial processes may alter the hydraulic conductivity of a geological environment. Column sediments were dominated by obligately alkaliphilic H2-oxidising bacteria, suggesting that the enrichment of these bacteria may have occurred as a result of H2 generation during organic acid metabolism. The results from these experiments show that microorganisms are able to carry out a number of processes under highly alkaline conditions that could potentially impact on the properties of the host rock surrounding a geological disposal facility for intermediate level radioactive waste. Copyright © 2016. Published by Elsevier B.V.

  13. Space disposal of nuclear wastes. Volume 1: Socio-political aspects

    NASA Technical Reports Server (NTRS)

    Laporte, T.; Rochlin, G. I.; Metlay, D.; Windham, P.

    1976-01-01

    The history and interpretation of radioactive waste management in the U.S., criteria for choosing from various options for waste disposal, and the impact of nuclear power growth from 1975 to 2000 are discussed. Preconditions for the existence of high level wastes in a form suitable for space disposal are explored. The role of the NASA space shuttle program in the space disposal of nuclear wastes, and the impact on program management, resources and regulation are examined.

  14. Flammability Control In A Nuclear Waste Vitrification System

    SciTech Connect

    Zamecnik, John R.; Choi, Alexander S.; Johnson, Fabienne C.; Miller, Donald H.; Lambert, Daniel P.; Stone, Michael E.; Daniel, William E. Jr.

    2013-07-25

    The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: 1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; 2) adjust feed rheology; and 3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid in pretreatment has been studied to eliminate the production of hydrogen in the pretreatment systems, which requires nuclear grade monitoring equipment. An alternative reductant, glycolic acid, has been studied as a substitute for formic acid. However, in the melter, the potential for greater formation of flammable gases exists with glycolic acid. Melter flammability is difficult to control because flammable mixtures can be formed during surges in offgases that both increase the amount of flammable species and decrease the temperature in the vapor space of the melter. A flammable surge can exceed the 60% of the LFL with no way to mitigate it. Therefore, careful control of the melter feed composition based on scaled melter surge testing is required. The results of engineering scale melter tests with the formic-nitric flowsheet and the use of these data in the melter flammability model are presented.

  15. USED NUCLEAR MATERIALS AT SAVANNAH RIVER SITE: ASSET OR WASTE?

    SciTech Connect

    Magoulas, V.

    2013-06-03

    The nuclear industry, both in the commercial and the government sectors, has generated large quantities of material that span the spectrum of usefulness, from highly valuable (“assets”) to worthless (“wastes”). In many cases, the decision parameters are clear. Transuranic waste and high level waste, for example, have no value, and is either in a final disposition path today, or – in the case of high level waste – awaiting a policy decision about final disposition. Other materials, though discardable, have intrinsic scientific or market value that may be hidden by the complexity, hazard, or cost of recovery. An informed decision process should acknowledge the asset value, or lack of value, of the complete inventory of materials, and the structure necessary to implement the range of possible options. It is important that informed decisions are made about the asset value for the variety of nuclear materials available. For example, there is a significant quantity of spent fuel available for recycle (an estimated $4 billion value in the Savannah River Site’s (SRS) L area alone); in fact, SRS has already blended down more than 300 metric tons of uranium for commercial reactor use. Over 34 metric tons of surplus plutonium is also on a path to be used as commercial fuel. There are other radiological materials that are routinely handled at the site in large quantities that should be viewed as strategically important and / or commercially viable. In some cases, these materials are irreplaceable domestically, and failure to consider their recovery could jeopardize our technological leadership or national defense. The inventories of nuclear materials at SRS that have been characterized as “waste” include isotopes of plutonium, uranium, americium, and helium. Although planning has been performed to establish the technical and regulatory bases for their discard and disposal, recovery of these materials is both economically attractive and in the national

  16. Hydrogen speciation in hydrated layers on nuclear waste glass

    SciTech Connect

    Aines, R.D.; Weed, H.C.; Bates, J.K.

    1987-01-15

    The hydration of an outer layer on nuclear waste glasses is known to occur during leaching, but the actual speciation of hydrogen (as water or hydroxyl groups) in these layers has not been determined. As part of the Nevada Nuclear Waste Storage Investigations Project, we have used infrared spectroscopy to determine hydrogen speciations in three nuclear waste glass compositions (SRL-131 & 165, and PNL 76-68), which were leached at 90{sup 0}C (all glasses) or hydrated in a vapor-saturated atmosphere at 202{sup 0}C (SRL-131 only). Hydroxyl groups were found in the surface layers of all the glasses. Molecular water was found in the surface of SRL-131 and PNL 76-68 glasses that had been leached for several months in deionized water, and in the vapor-hydrated sample. The water/hydroxyl ratio increases with increasing reaction time; molecular water makes up most of the hydrogen in the thick reaction layers on vapor-phase hydrated glass while only hydroxyl occurs in the least reacted samples. Using the known molar absorptivities of water and hydroxyl in silica-rich glass the vapor-phase layer contained 4.8 moles/liter of molecular water, and 0.6 moles water in the form hydroxyl. A 15 {mu}m layer on SRL-131 glass formed by leaching at 90{sup 0}C contained a total of 4.9 moles/liter of water, 2/3 of which was as hydroxyl. The unreacted bulk glass contains about 0.018 moles/liter water, all as hydroxyl. The amount of hydrogen added to the SRL-131 glass was about 70% of the original Na + Li content, not the 300% that would result from alkali=hydronium ion interdiffusion. If all the hydrogen is then assumed to be added as the result of alkali-H{sup +} interdiffusion, the molecular water observed may have formed from condensation of the original hydroxyl groups.

  17. Radioactive waste isolation in salt: peer review of the Office of Nuclear Waste Isolation's report on Functional Design Criteria for a Repository for High-Level Radioactive Waste

    SciTech Connect

    Hambley, D.F.; Russell, J.E.; Busch, J.S.; Harrison, W.; Edgar, D.E.; Tisue, M.W.

    1984-08-01

    This report summarizes Argonne's review of the Office of Nuclear Waste Isolation's (ONWI's) draft report entitled Functional Design Criteria for High-Level Nuclear Waste Repository in Salt, dated January 23, 1984. Recommendations are given for improving the ONWI draft report.

  18. Radioactive waste isolation in salt: peer review of Office of Nuclear Waste Isolation's Socioeconomic Program Plan

    SciTech Connect

    Winter, R.; Fenster, D.; O'Hare, M.; Zillman, D.; Harrison, W.; Tisue, M.

    1984-07-01

    The following recommendations have been abstracted from the body of this report. The Office of Nuclear Waste Isolation's Socioeconomic Program Plan for the Establishment of Mined Geologic Repositories to Isolate Nuclear Waste should be modified to: (1) encourage active public participation in the decision-making processes leading to repository site selection; (2) clearly define mechanisms for incorporating the concerns of local residents, state and local governments, and other potentially interested parties into the early stages of the site selection process. In addition, the Office of Nuclear Waste Isolation should carefully review the overall role that these persons and groups, including local pressure groups organized in the face of potential repository development, will play in the siting process; (3) place significantly greater emphasis on using primary socioeconomic data during the site selection process, reversing the current overemphasis on secondary data collection, description of socioeconomic conditions at potential locations, and development of analytical methodologies; (4) include additional approaches to solving socioeconomic problems. For example, a reluctance to acknowledge that solutions to socioeconomic problems need to be found jointly with interested parties is evident in the plan; (5) recognize that mitigation mechanisms other than compensation and incentives may be effective; (6) as soon as potential sites are identified, the US Department of Energy (DOE) should begin discussing impact mitigation agreements with local officials and other interested parties; and (7) comply fully with the pertinent provisions of NWPA.

  19. Initial studies to assess microbial impacts on nuclear waste disposal

    SciTech Connect

    Horn, J.M.; Meike, A.; McCright, R.D.; Economides, B.

    1996-02-20

    The impacts of the native and introduced bacteria on the performance of geologic nuclear waste disposal facilities should be evaluated because these bacteria could promote corrosion of repository components and alteration of chemical and hydrological properties of the surrounding engineered and rock barriers. As a first step towards investigating these potentialities, native and introduced bacteria obtained from post-construction Yucca Mountain (YM) rock were isolated under varying conditions, including elevated temperature, low nutrient availability, and the absence of available oxygen. Individual isolates are being screened for activities associated with microbially induced corrosion of metals (MIC). Preliminary determination of growth rates of whole YM microbial communities under varying conditions was also undertaken.

  20. Critique of rationale for transmutation of nuclear waste

    SciTech Connect

    Smith, C.F.; Cohen, J.J.

    1980-07-01

    It has been suggested that nuclear transmutation could be used in the elimination or reduction of hazards from radioactive wastes. The rationale for this suggestion is the subject of this paper. The objectives of partitioning-transmutation are described. The benefits are evaluated. The author concludes that transmutation would appear at best to offer the opportunity of reducing an already low risk. This would not seem to be justifiable considering the cost. If non-radiological risks are considered, there is a negative total benefit. (DC)

  1. Evaluation of refractory materials for a nuclear waste incinerator

    SciTech Connect

    Grotzky, V. K.; Kneale, P. A.; Teter, A. R.

    1980-07-21

    An experiment to find a suitable refractory lining for a nuclear waste incinerator has been completed. Eleven brick and six castable products were analyzed by optical and scanning microscopy. All the materials were fashioned into cup shapes and subjected to temperatures ranging from 800 to 1200/sup 0/C for as long as six weeks. Some of the cups were charged weekly with pellets made from ash materials that would contact an incinerator liner. Refractory products containing a high percentage of aluminum oxide had the greatest resistance to cracking and slag buildup. 35 figures.

  2. Double Diffusive Natural Convection in a Nuclear Waste Repository

    SciTech Connect

    Y. Hao; J. Nitao; T.A. Buscheck; Y. Sun

    2006-03-28

    In this study, we conduct a two-dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have strong impacts on the in-drift convective flow and transport.

  3. Double Diffusive Natural Convection in a Nuclear Waste Repository

    SciTech Connect

    Hao, Y; Nitao, J; Buscheck, T A; Sun, Y

    2006-02-03

    In this study, we conduct a two-dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have strong impacts on the in-drift convective flow and transport.

  4. THERMODYNAMIC TABLES FOR NUCLEAR WASTE ISOLATION, V.1: AQUEOUSSOLUTIONS DATABASE

    SciTech Connect

    Phillips, S.L.; Hale, F.V.; Silvester, L.F.

    1988-05-01

    Tables of consistent thermodynamic property values for nuclear waste isolation are given. The tables include critically assessed values for Gibbs energy of formation. enthalpy of formation, entropy and heat capacity for minerals; solids; aqueous ions; ion pairs and complex ions of selected actinide and fission decay products at 25{sup o}C and zero ionic strength. These intrinsic data are used to calculate equilibrium constants and standard potentials which are compared with typical experimental measurements and other work. Recommendations for additional research are given.

  5. Thermodynamic data management system for nuclear waste disposal performance assessment

    SciTech Connect

    Phillips, S.L.; Hale, F.V.; Siegel, M.D.

    1988-04-01

    Thermodynamic property values for use in assessing the performance of a nuclear waste repository are described. More emphasis is on a computerized data base management system which facilitates use of the thermodynamic data in sensitivity analysis and other studies which critically assess the performance of disposal sites. Examples are given of critical evaluation procedures; comparison of apparent equilibrium constants calculated from the data base, with other work; and of correlations useful in estimating missing values of both free energy and enthalpy of formation for aqueous species. 49 refs., 11 figs., 6 tabs.

  6. Shale: an overlooked option for US nuclear waste disposal

    USGS Publications Warehouse

    Neuzil, Christopher E.

    2014-01-01

    Toss a dart at a map of the United States and, more often than not, it will land where shale can be found underground. A drab, relatively featureless sedimentary rock that historically attracted little interest, shale (as used here, the term includes clay and a range of clay-rich rocks) is entering Americans’ consciousness as a new source of gas and oil. But shale may also offer something entirely different—the ability to safely and permanently house high-level nuclear waste.

  7. Double Diffusive Natural Convection in a Nuclear Waste Repository

    SciTech Connect

    Hao, Y; Nitao, J J; Buscheck, T A; Sun, Y

    2006-07-24

    In this study, we conduct a two dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have a strong impact on in-drift convective flow and transport.

  8. Ultrafiltration treatment for liquid laundry wastes from nuclear power stations

    SciTech Connect

    Kichik, V.A.; Maslova, M.N.; Svittsov, A.A.; Kuleshov, N.F.

    1988-03-01

    The authors conduct a comprehensive analysis of the waste constituents--radioactive and organic--of the laundry water resulting from the on-site laundering and decontamination of clothing worn in nuclear power plants. The primary isotope contaminants consist of niobium and zirconium 95, manganese 54, cobalt 60, iron 59, and cesium 134 and 137. A variety of filter and adsorbent materials used in an ultrafiltration process are comparatively tested for their effectiveness in removing not only these isotopes but also the organic contaminants in the process of recycling the water. Those materials consist of copper hexacyanoferrate, polyacrylophosphonic acid, and several metal-polymer complexes.

  9. Idaho Nuclear Technology and Engineering Center Newly Generated Liquid Waste Demonstration Project Feasibility Study

    SciTech Connect

    Herbst, A.K.

    2000-02-01

    A research, development, and demonstration project for the grouting of newly generated liquid waste (NGLW) at the Idaho Nuclear Technology and Engineering Center is considered feasible. NGLW is expected from process equipment waste, decontamination waste, analytical laboratory waste, fuel storage basin waste water, and high-level liquid waste evaporator condensate. The potential grouted waste would be classed as mixed low-level waste, stabilized and immobilized to meet RCRA LDR disposal in a grouting process in the CPP-604 facility, and then transported to the state.

  10. System analyses on advanced nuclear fuel cycle and waste management

    NASA Astrophysics Data System (ADS)

    Cheon, Myeongguk

    To evaluate the impacts of accelerator-driven transmutation of waste (ATW) fuel cycle on a geological repository, two mathematical models are developed: a reactor system analysis model and a high-level waste (HLW) conditioning model. With the former, fission products and residual trans-uranium (TRU) contained in HLW generated from a reference ATW plant operations are quantified and the reduction of TRU inventory included in commercial spent-nuclear fuel (CSNF) is evaluated. With the latter, an optimized waste loading and composition in solidification of HLW are determined and the volume reduction of waste packages associated with CSNF is evaluated. WACOM, a reactor system analysis code developed in this study for burnup calculation, is validated by ORIGEN2.1 and MCNP. WACOM is used to perform multicycle analysis for the reference lead-bismuth eutectic (LBE) cooled transmuter. By applying the results of this analysis to the reference ATW deployment scenario considered in the ATW roadmap, the HLW generated from the ATW fuel cycle is quantified and the reduction of TRU inventory contained in CSNF is evaluated. A linear programming (LP) model has been developed for determination of an optimized waste loading and composition in solidification of HLW. The model has been applied to a US-defense HLW. The optimum waste loading evaluated by the LP model was compared with that estimated by the Defense Waste Processing Facility (DWPF) in the US and a good agreement was observed. The LP model was then applied to the volume reduction of waste packages associated with CSNF. Based on the obtained reduction factors, the expansion of Yucca Mountain Repository (YMR) capacity is evaluated. It is found that with the reference ATW system, the TRU contained in CSNF could be reduced by a factor of ˜170 in terms of inventory and by a factor of ˜40 in terms of toxicity under the assumed scenario. The number of waste packages related to CSNF could be reduced by a factor of ˜8 in terms of

  11. SPENT NUCLEAR FUEL WASTE PACKAGE FILLER TESTING TECHNICAL GUIDELINES DOCUMENT

    SciTech Connect

    J.A. Cogar

    1996-08-28

    The purpose of this work is to provide supporting calculations for determination of the radiation source terms specific to subsurface shielding design and analysis. These calculations are not intended to provide the absolute values of the source terms, which are under the charter of the Waste Package Operations (WPO) Group. Rather, the calculations focus on evaluation of the various combinations of fuel enrichment, burnup and cooling time for a given decay heat output, consistent with the waste package (WP) thermal design basis. The objective is to determine the worst-case combination of the fuel characteristics (enrichment, burnup and cooling time) which would give the maximum radiation fields for subsurface shielding considerations. The calculations are limited to PWR fuel only, since the WP design is currently evolving with thinner walls and a reduced heat load as compared to the viability assessment (VA) reference design. The results for PWR fuel will provide a comparable indication of the trend for BWR fuel, as their characteristics are similar. The source term development for defense high-level waste and other spent nuclear fuel (SNF) is the responsibility of the WPO Group, and therefore, is not included this work. This work includes the following items responsive to the stated purpose and objective: (1) Determine the possible fuel parameters (initial enrichment, burnup and cooling time), that give the same decay heat value as specified for the waste package thermal design; (2) Obtain the neutron and gamma source terms for the various combinations of the fuel parameters for use in radiation field calculations; and (3) Calculate radiation fields on the surfaces of the waste package and its transporter to quantify the effects of the fuel parameters with the same decay heat value for use in identifying the worst-case combination of the fuel parameters.

  12. Myth of nuclear explosions at waste disposal sites

    SciTech Connect

    Stratton, W.R.

    1983-10-01

    Approximately 25 years ago, an event is said to have occurred in the plains immediately west of the southern Ural mountains of the Soviet Union that is being disputed to this very day. One person says it was an explosion of nuclear wastes buried in a waste disposal site; other people say it was an above-ground test of an atomic weapon; still others suspect that an alleged contaminated area (of unknown size or even existence) is the result of a series of careless procedures. Since the event, a number of articles about the disposal-site explosion hypothesis written by a Soviet exile living in the United Kingdom have been published. Although the Soviet scientist's training and background are in the biological sciences and his knowledge of nuclear physics or chemistry is limited, people who oppose the use of nuclear energy seem to want to believe what he says without question. The work of this Soviet biologist has received wide exposure both in the United Kingdom and the United States. This report presents arguments against the disposal-site explosion hypothesis. Included are discussions of the amounts of plutonium that would be in a disposal site, the amounts of plutonium that would be needed to reach criticality in a soil-water-plutonium mixture, and experiments and theoretical calculations on the behavior of such mixtures. Our quantitative analyses show that the postulated nuclear explosion is so improbable that it is essentially impossible and can be found only in the never-never land of an active imagination. 24 references, 14 figures, 5 tables.

  13. Heat Transfer in Waste Glass Melts - Measurement and Implications for Nuclear Waste Vitrification

    NASA Astrophysics Data System (ADS)

    Wang, Chuan

    Thermal properties of waste glass melts, such as high temperature density and thermal conductivity, are relevant to heat transfer processes in nuclear waste vitrification. Experimental measurement techniques were developed and applied to four nuclear waste glasses representative of those currently projected for treatment of Hanford HLW and LAW streams to study heat flow mechanisms in nuclear waste vitrification. Density measurement results by Archimedes' method indicated that densities of the melts investigated varied considerably with composition and temperature. Thermal diffusivities of waste melts were determined at nominal melter operating temperatures using a temperature-wave technique. Thermal conductivities were obtained by combining diffusivity data with the experimentally-acquired densities of the melts and their known heat capacities. The experimental results display quite large positive dependences of conductivities on temperature for some samples and much weaker positive temperature dependences for others. More importantly, there is observed a big change in the slopes of the conductivities versus temperature as temperature is increased for two of the melts, but not for the other two. This behavior was interpreted in terms of the changing contributions of radiation and conduction with temperature and composition dependence of the absorption coefficient. Based on the obtained thermal conductivities, a simple model for a waste glass melter was set up, which was used to analyze the relative contributions of conduction and radiation individually and collectively to the overall heat flow and to investigate factors and conditions that influence the radiation contribution to heat flow. The modeling results showed that unlike the case at lower temperatures, the radiant energy flow through waste melts could be predominant compared with conduction at temperature of about 900 °C or higher. However, heat flow due to radiation was roughly equal to that from

  14. Reversing nuclear opposition: evolving public acceptance of a permanent nuclear waste disposal facility.

    PubMed

    Jenkins-Smith, Hank C; Silva, Carol L; Nowlin, Matthew C; deLozier, Grant

    2011-04-01

    Nuclear facilities have long been seen as the top of the list of locally unwanted land uses (LULUs), with nuclear waste repositories generating the greatest opposition. Focusing on the case of the Waste Isolation Pilot Plant (WIPP) in southern New Mexico, we test competing hypotheses concerning the sources of opposition and support for siting the facility, including demographics, proximity, political ideology, and partisanship, and the unfolding policy process over time. This study tracks the changes of risk perception and acceptance of WIPP over a decade, using measures taken from 35 statewide surveys of New Mexico citizens spanning an 11-year period from fall 1990 to summer 2001. This time span includes periods before and after WIPP became operational. We find that acceptance of WIPP is greater among those whose residences are closest to the WIPP facility. Surprisingly, and contrary to expectations drawn from the broader literature, acceptance is also greater among those who live closest to the nuclear waste transportation route. We also find that ideology, partisanship, government approval, and broader environmental concerns influence support for WIPP acceptance. Finally, the sequence of procedural steps taken toward formal approval of WIPP by government agencies proved to be important to gaining public acceptance, the most significant being the opening of the WIPP facility itself.

  15. 76 FR 17970 - Board Meeting: April 27, 2011-Amherst, New York; the U.S. Nuclear Waste Technical Review Board...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting: April 27, 2011--Amherst, New York; the U.S. Nuclear Waste Technical Review... 5051 of Public Law 100-203, Nuclear Waste Policy Amendments Act of 1987, the U.S. Nuclear...

  16. 25 CFR 170.900 - What is the purpose of the provisions relating to transportation of hazardous and nuclear waste?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... transportation of hazardous and nuclear waste? 170.900 Section 170.900 Indians BUREAU OF INDIAN AFFAIRS... and Nuclear Waste Transportation § 170.900 What is the purpose of the provisions relating to transportation of hazardous and nuclear waste? Sections 170.900 through 170.907 on transportation of nuclear...

  17. Nuclear waste management and the use of the sea. Special report

    SciTech Connect

    Not Available

    1984-04-01

    This report reviews the current situation on nuclear waste disposal policies in the United States and elsewhere and relates these policies to implications for the oceans. The report does not comment on nuclear power as an energy source. In a comprehensive background information section, the report describes the worldwide inventory of radioactive waste, the varying types of radioactive wastes, international and domestic laws governing radioactive waste disposal, scientific analysis of marine radioactivity, and possible U.S. proposals on ocean disposal of nuclear waste. Detailed appendices describe nuclear and health physics, waste management strategies of other nations, prior U.S. dumping of radioactive wastes, signatories to the London Dumping Convention, specific case histories, among others.

  18. Monte-Carlo Application for Nondestructive Nuclear Waste Analysis

    NASA Astrophysics Data System (ADS)

    Carasco, C.; Engels, R.; Frank, M.; Furletov, S.; Furletova, J.; Genreith, C.; Havenith, A.; Kemmerling, G.; Kettler, J.; Krings, T.; Ma, J.-L.; Mauerhofer, E.; Neike, D.; Payan, E.; Perot, B.; Rossbach, M.; Schitthelm, O.; Schumann, M.; Vasquez, R.

    2014-06-01

    Radioactive waste has to undergo a process of quality checking in order to check its conformance with national regulations prior to its transport, intermediate storage and final disposal. Within the quality checking of radioactive waste packages non-destructive assays are required to characterize their radio-toxic and chemo-toxic contents. The Institute of Energy and Climate Research - Nuclear Waste Management and Reactor Safety of the Forschungszentrum Jülich develops in the framework of cooperation nondestructive analytical techniques for the routine characterization of radioactive waste packages at industrial-scale. During the phase of research and development Monte Carlo techniques are used to simulate the transport of particle, especially photons, electrons and neutrons, through matter and to obtain the response of detection systems. The radiological characterization of low and intermediate level radioactive waste drums is performed by segmented γ-scanning (SGS). To precisely and accurately reconstruct the isotope specific activity content in waste drums by SGS measurement, an innovative method called SGSreco was developed. The Geant4 code was used to simulate the response of the collimated detection system for waste drums with different activity and matrix configurations. These simulations allow a far more detailed optimization, validation and benchmark of SGSreco, since the construction of test drums covering a broad range of activity and matrix properties is time consuming and cost intensive. The MEDINA (Multi Element Detection based on Instrumental Neutron Activation) test facility was developed to identify and quantify non-radioactive elements and substances in radioactive waste drums. MEDINA is based on prompt and delayed gamma neutron activation analysis (P&DGNAA) using a 14 MeV neutron generator. MCNP simulations were carried out to study the response of the MEDINA facility in terms of gamma spectra, time dependence of the neutron energy spectrum

  19. Gamma radiation induced changes in nuclear waste glass containing Eu

    NASA Astrophysics Data System (ADS)

    Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Kaushik, C. P.; Tomar, B. S.; Godbole, S. V.

    2011-10-01

    Gamma radiation induced changes were investigated in sodium-barium borosilicate glasses containing Eu. The glass composition was similar to that of nuclear waste glasses used for vitrifying Trombay research reactor nuclear waste at Bhabha Atomic Research Centre, India. Photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques were used to study the speciation of the rare earth (RE) ion in the matrix before and after gamma irradiation. Judd-Ofelt ( J- O) analyses of the emission spectra were done before and after irradiation. The spin counting technique was employed to quantify the number of defect centres formed in the glass at the highest gamma dose studied. PL data suggested the stabilisation of the trivalent RE ion in the borosilicate glass matrix both before and after irradiation. It was also observed that, the RE ion distributes itself in two different environments in the irradiated glass. From the EPR data it was observed that, boron oxygen hole centre based radicals are the predominant defect centres produced in the glass after irradiation along with small amount of E’ centres. From the spin counting studies the concentration of defect centres in the glass was calculated to be 350 ppm at 900 kGy. This indicated the fact that bulk of the glass remained unaffected after gamma irradiation up to 900 kGy.

  20. Disposition of nuclear waste using subcritical accelerator-driven systems

    SciTech Connect

    Venneri, F.; Li, N.; Williamson, M.; Houts, M.; Lawrence, G.

    1998-12-31

    Spent fuel from nuclear power plants contains large quantities of Pu, other actinides, and fission products (FP). This creates challenges for permanent disposal because of the long half-lives of some isotopes and the potential for diversion of the fissile material. Two issues of concern for the US repository concept are: (1) long-term radiological risk peaking tens-of-thousands of years in the future; and (2) short-term thermal loading (decay heat) that limits capacity. An accelerator-driven neutron source can destroy actinides through fission, and can convert long-lived fission products to shorter-lived or stable isotopes. Studies over the past decade have established that accelerator transmutation of waste (ATW) can have a major beneficial impact on the nuclear waste problem. Specifically, the ATW concept the authors are evaluating: (1) destroys over 99.9% of the actinides; (2) destroys over 99.9% of the Tc and I; (3) separates Sr-90 and Cs-137; (4) separates uranium from the spent fuel; (5) produces electric power.

  1. Incorporation of simulated high-level nuclear waste in gel spheres

    SciTech Connect

    Arnold, W.D.; Bond, W.D.; Robinson, S.M.

    1982-12-01

    Gel sphere technology developed for reactor fuel fabrication was applied to the fixation of simulated high-level radioactive waste in crystalline ceramic form for permanent disposal. Gel spheres containing simulated alkaline defense waste sludges and ceramic matrix materials were prepared by internal gelation at waste loadings as high as 90%. The gel spheres were amenable to subsequent drying, sintering, and coating procedures to produce crystalline waste forms with extremely high leach resistances. Potential application of this technique to the processing of commercial power reactor waste was demonstrated by incorporating simulated Purex solvent extraction waste in gel spheres with up to 20% waste loading. Cesium present in the simulated waste was adsorbed on zeolite and immobilized by coating with carbon.

  2. Nuclear characteristics of vitrified high-level waste at the West Valley Demonstration Project

    SciTech Connect

    Arakali, V.S.; Barnes, S.M. )

    1991-11-01

    High-level liquid nuclear waste stored in underground tanks at West Valley, New York, will be vitrified as borosilicate glass and stored in stainless steel canisters prior to disposal at a waste repository. The nuclear characteristics of the vitrified waste must meet certain repository design specifications. This paper presents an evaluation of the waste form produced at West Valley with respect to its compliance to the repository specifications of heat and gas generation rates and neutron and gamma dose rates. The method consists of analyzing the composition of liquid nuclear waste in underground tanks and estimating the amount of other chemicals needed to encapsulate radionuclides in glass matrices. The number of waste canisters and the composition of each batch of canistered waste are determined from the vitrification process flow sheet. This data is used in computer codes to evaluate the waste form against repository specifications.

  3. Separation of technetium from nuclear waste stream simulants. Final report

    SciTech Connect

    Strauss, S.H.

    1995-09-11

    The author studied liquid anion exchangers, such as Aliquat-336 nitrate, various pyridinium nitrates, and related salts, so that they may be applied toward a specific process for extracting (partitioning) and recovering {sup 99}TcO{sub 4}{sup {minus}} from nuclear waste streams. Many of the waste streams are caustic and contain a variety of other ions. For this reason, the author studied waste stream simulants that are caustic and contain appropriate concentrations of selected, relevant ions. Methods of measuring the performance of the exchangers and extractant systems included contact experiments. Batch contact experiments were used to determine the forward and reverse extraction parameters as a function of temperature, contact time, phase ratio, concentration, solvent (diluent), and other physical properties. They were also used for stability and competition studies. Specifically, the author investigated the solvent extraction behavior of salts of perrhenate (ReO{sub 4}{sup {minus}}), a stable (non-radioactive) chemical surrogate for {sup 99}TcO{sub 4}{sup {minus}}. Results are discussed for alternate organic solvents; metalloporphyrins, ferrocenes, and N-cetyl pyridium nitrate as alternate extractant salts; electroactive polymers; and recovery of ReO{sub 4}{sup {minus}} and TcO{sub 4}{sup {minus}}.

  4. Radiation effects in nuclear waste materials. 1997 annual progress report

    SciTech Connect

    Weber, W.J.; Corrales, L.R.

    1997-06-01

    'The objective of this multidisciplinary, multi-institutional research effort is to develop a fundamental understanding at the atomic, microscopic, and macroscopic levels of radiation effects in glass and ceramics. This research will provide the underpinning science and models for evaluation and performance assessments of glass and ceramic waste forms for the immobilization and disposal of high-level tank waste, plutonium residues and scrap, and excess weapons plutonium. Studies will focus on the effects of ionization and elastic collision interactions on defect production, defect interactions, diffusion, solid-state phase transformations, and gas accumulation using actinide-containing materials, gamma irradiation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of a-decay and p-decay on nuclear waste glasses and ceramics. This program will exploit a variety of structural, optical, and spectroscopic probes to characterize the nature and behavior of the defects, defect aggregates, and phase transforma-tions. Computer simulation techniques will be used to determine defect production, calculate defect stability, defect energies, damage processes within an a-recoil cascade, and defect/gas diffusion and interactions. A number of irradiation facilities and capabilities will be used, including user facilities at several national laboratories, to study the effects of irradiation under different conditions.'

  5. RECENT STUDIES OF URANIUM AND PLUTONIUM CHEMISTRY IN ALKALINE RADIOACTIVE WASTE SOLUTIONS

    SciTech Connect

    King, W; Bill Wilmarth, B; David Hobbs, D; Tommy Edwards, T

    2006-06-13

    Solubility studies of uranium and plutonium in a caustic, radioactive Savannah River Site tank waste solution revealed the existence of uranium supersaturation in the as-received sample. Comparison of the results to predictions generated from previously published models for solubility in these waste types revealed that the U model poorly predicts solubility while Pu model predictions are quite consistent with experimental observations. Separate studies using simulated Savannah River Site evaporator feed solution revealed that the known formation of sodium aluminosilicate solids in waste evaporators can promote rapid precipitation of uranium from supersaturated solutions.

  6. Migration of radionuclides through backfill in a nuclear waste repository

    SciTech Connect

    Lung, H.

    1986-01-01

    Four models are analyzed to predict the performance of a backfill layer as part of the waste package emplacement in a nuclear waste repository. The corresponding computer code for each model is also developed. The time-dependent mass transfer analysis on a spherical waste-backfill geometry indicates that the radioactive decay effect can enhance the mass transfer rate from the backfill instead of reducing it. The analysis yields the breakthrough time of the backfill layer, which in turn characterizes the backfill performance. A non-linear (Langmuir) sorption isotherm is used to describe the sorption saturation in the backfill. The steady state mass transport analysis through a prolate spheroidal waste-backfill geometry shows that a simple formula can be used to calculate the individual resistances to mass transport in backfill and in host rock. A general, non-recursive analytical solution is derived for a radioactive decay chain of arbitrary length in either a finite or a semi-infinite medium. Numerical examples are given for different boundary conditions and for different decay chains. The results justify that for a backfill layer made of low permeability material, a zero water velocity can be used in the backfill analysis. It is also shown that under normal repository conditions, the mass transfer rate from the backfill is quite small. For the daughter member with a smaller retardation coefficient than that of the mother nuclide, such as /sup 226/Ra in the /sup 234/U ..-->.. /sup 230/Th ..-->.. /sup 226/Ra chain, an interior maximum in the concentration profile appears in the backfill. This phenomenon can be seen only in a chain calculation.

  7. IRON PHOSPHATE GLASSES: AN ALTERNATIVE FOR VITRIFYING CERTAIN NUCLEAR WASTES

    SciTech Connect

    Day, Delbert E.; Kim, Cheol-Woon

    2004-06-28

    The unusual properties and beneficial characteristics of iron phosphate glasses, as viewed from the standpoint of alternative glasses for vitrifying nuclear and hazardous wastes (which contain components that make them poorly suited for vitrification in borosilicate glass), have been investigated by the University of Missouri-Rolla with support from the Environmental Management Science Program (EMSP), DOE [DEFG07- 96ER45618]. During the past year, the corrosion resistance of Inconel 690 and 693 coupons submerged in an iron phosphate melt at 1050 C for up to 155 days has been investigated to determine whether iron phosphate glasses could be melted in a Joule Heated Melter (JHM) equipped with such electrodes in the same manner as now being used to melt borosilicate glass. Substituting iron phosphate glasses for borosilicate glasses could significantly reduce the time and cost for clean up due to the higher waste loading possible in iron phosphate glass. The iron phosphate melt, which contained 30 wt% of the Hanford Low Activity Waste (LAW), did not corrode the Inconel 690 to any greater extent than what has been reported for Inconel 690 electrodes in the borosilicate melt in the JHM at the Defense Waste Processing Facility. Furthermore, Inconel 693 appeared to be an even better candidate for use in iron phosphate melts since its corrosion rate (0.7 {micro}m/day) was only about one half that (1.3 {micro}m/day) of Inconel 690. In the past year, the results of the research on iron phosphate glasses have been described in nine technical papers and one report and have been presented at four international and national meetings.

  8. Technetium in alkaline, high-salt, radioactive tank waste supernate: Preliminary characterization and removal

    SciTech Connect

    Blanchard, D.L. Jr.; Brown, G.N.; Conradson, S.D.

    1997-01-01

    This report describes the initial work conducted at Pacific Northwest National Laboratory to study technetium (Tc) removal from Hanford tank waste supernates and Tc oxidation state in the supernates. Filtered supernate samples from four tanks were studied: a composite double shell slurry feed (DSSF) consisting of 70% from Tank AW-101, 20% from AP-106, and 10% from AP-102; and three complexant concentrate (CC) wastes (Tanks AN-107, SY-101, ANS SY-103) that are distinguished by having a high concentration of organic complexants. The work included batch contacts of these waste samples with Reillex{trademark}-HPQ (anion exchanger from Reilly Industries) and ABEC 5000 (a sorbent from Eichrom Industries), materials designed to effectively remove Tc as pertechnetate from tank wastes. A short study of Tc analysis methods was completed. A preliminary identification of the oxidation state of non-pertechnetate species in the supernates was made by analyzing the technetium x-ray absorption spectra of four CC waste samples. Molybdenum (Mo) and rhenium (Re) spiked test solutions and simulants were tested with electrospray ionization-mass spectrometry to evaluate the feasibility of the technique for identifying Tc species in waste samples.

  9. Waste form development and characterization in pyrometallurgical treatment of spent nuclear fuel.

    SciTech Connect

    Ackerman, J.

    1998-04-16

    Electrometallurgical treatment is a compact, inexpensive method that is being developed at Argonne National Laboratory to deal with spent nuclear fuel, primarily metallic and oxide fuels. In this method, metallic nuclear fuel constituents are electrorefined in a molten salt to separate uranium from the rest of the spent fuel. Oxide and other fuels are subjected to appropriate head end steps to convert them to metallic form prior to electrorefining. The treatment process generates two kinds of high-level waste--a metallic and a ceramic waste. Isolation of these wastes has been developed as an integral part of the process. The wastes arise directly from the electrorefiner, and waste streams do not contain large quantities of solvent or other process fluids. Consequently, waste volumes are small and waste isolation processes can be compact and rapid. This paper briefly summarizes waste isolation processes then describes development and characterization of the two waste forms in more detail.

  10. Corrosion issues in high-level nuclear waste containers

    NASA Astrophysics Data System (ADS)

    Asl, Samin Sharifi

    In this dissertation different aspects of corrosion and electrochemistry of copper, candidate canister material in Scandinavian high-level nuclear waste disposal program, including the thermodynamics and kinetics of the reactions that are predicted to occur in the practical system have been studied. A comprehensive thermodynamic study of copper in contact with granitic groundwater of the type and composition that is expected in the Forsmark repository in Sweden has been performed. Our primary objective was to ascertain whether copper would exist in the thermodynamically immune state in the repository, in which case corrosion could not occur and the issue of corrosion in the assessment of the storage technology would be moot. In spite of the fact that metallic copper has been found to exist for geological times in granitic geological formations, copper is well-known to be activated from the immune state to corrode by specific species that may exist in the environment. The principal activator of copper is known to be sulfur in its various forms, including sulfide (H2S, HS-, S2-), polysulfide (H2Sx, HSx -, Sx 2-), poly sulfur thiosulfate ( SxO3 2-), and polythionates (SxO6 2-). A comprehensive study of this aspect of copper chemistry has never been reported, and yet an understanding of this issue is vital for assessing whether copper is a suitable material for fabricating canisters for the disposal of HLNW. Our study identifies and explores those species that activate copper; these species include sulfur-containing entities as well as other, non-sulfur species that may be present in the repository. The effects of temperature, solution pH, and hydrogen pressure on the kinetics of the hydrogen electrode reaction (HER) on copper in borate buffer solution have been studied by means of steady-state polarization measurements, including electrochemical impedance spectroscopy (EIS). In order to obtain electrokinetic parameters, such as the exchange current density and the

  11. CESAR: A Code for Nuclear Fuel and Waste Characterisation

    SciTech Connect

    Vidal, J.M.; Grouiller, J.P.; Launay, A.; Berthion, Y.; Marc, A.; Toubon, H.

    2006-07-01

    CESAR (Simplified Evolution Code Applied to Reprocessing) is a depletion code developed through a joint program between CEA and COGEMA. In the late 1980's, the first use of this code dealt with nuclear measurement at the Laboratories of the La Hague reprocessing plant. The use of CESAR was then extended to characterizations of all entrance materials and for characterisation, via tracer, of all produced waste. The code can distinguish more than 100 heavy nuclides, 200 fission products and 100 activation products, and it can characterise both the fuel and the structural material of the fuel. CESAR can also make depletion calculations from 3 months to 1 million years of cooling time. Between 2003-2005, the 5. version of the code was developed. The modifications were related to the harmonisation of the code's nuclear data with the JEF2.2 nuclear data file. This paper describes the code and explains the extensive use of this code at the La Hague reprocessing plant and also for prospective studies. The second part focuses on the modifications of the latest version, and describes the application field and the qualification of the code. Many companies and the IAEA use CESAR today. CESAR offers a Graphical User Interface, which is very user-friendly. (authors)

  12. 75 FR 61228 - Board Meeting: Technical Lessons Gained From High-Level Nuclear Waste Disposal Efforts

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting: Technical Lessons Gained From High-Level Nuclear Waste Disposal Efforts... Board will consider technical lessons that can be gained from those experiences that may be useful...

  13. Calcined Waste Storage at the Idaho Nuclear Technology and Engineering Center

    SciTech Connect

    M. D. Staiger M. C. Swenson

    2007-06-01

    This report provides a quantitative inventory and composition (chemical and radioactivity) of calcined waste stored at the Idaho Nuclear Technology and Engineering Center. From December 1963 through May 2000, liquid radioactive wastes generated by spent nuclear fuel reprocessing were converted into a solid, granular form called calcine. This report also contains a description of the calcine storage bins.

  14. Effects of an acid/alkaline treatment on the release of antioxidants and cellulose from different agro-food wastes.

    PubMed

    Vadivel, Vellingiri; Moncalvo, Alessandro; Dordoni, Roberta; Spigno, Giorgia

    2017-06-01

    The present investigation was aimed to evaluate the release of both antioxidants and cellulosic fibre from different agro-food wastes. Cost-effective and easily available agro-food residues (brewers' spent grains, hazelnut shells, orange peels and wheat straw) were selected and submitted to a double-step acid/alkaline fractionation process. The obtained acid and alkaline liquors were analysed for total phenols content and antioxidant capacity. The final fibre residue was analysed for the cellulose, lignin and hemicellulose content. The total phenols content and antioxidant capacity of the acid liquors were higher than the alkaline hydrolysates. Orange peels and wheat straw gave, respectively, the highest (19.70±0.68mg/gdm) and the lowest (4.70±0.29mg/gdm) total phenols release. Correlation between antioxidant capacity of the liquors and their origin depended on the analytical assay used to evaluate it. All the acid liquors were also rich in sugar degradation products (mainly furfural). HPLC analysis revealed that the most abundant phenolic compound in the acid liquors was vanillin for brewers' spent grains, hazelnut shells and wheat straw, and p-hydroxybenzoic acid for orange peels. Wheat straw served as the best raw material for cellulose isolation, providing a final residue with a high cellulose content (84%) which corresponded to 45% of the original cellulose. The applied process removed more than 90% of the hemicellulose fraction in all the samples, while delignification degree ranged from 67% (in hazelnut shells), to 93% (in brewers' spent grains). It was not possible to select a unique raw material for the release of highest levels of both total phenols and cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Abyssal Sequestration of Nuclear Waste in Earth's Crust

    NASA Astrophysics Data System (ADS)

    Germanovich, L. N.; Garagash, D.; Murdoch, L. C.; Robinowitz, M.

    2013-12-01

    This work outlines a new method for disposing of hazardous (e.g., nuclear) waste. The technique is called Abyssal Sequestration, and it involves placing the waste at extreme depths in Earth's crust where it could achieve the geologically-long period of isolation. Abyssal Sequestration involves storing the waste in hydraulic fractures driven by gravity, a process we term gravity fracturing. In short, we suggest creating a dense fluid (slurry) containing waste, introducing the fluid into a fracture, and extending the fracture downward until it becomes long enough to propagate independently. The fracture will continue to propagate downward to great depth, permanently isolating the waste. Storing solid wastes by mixing them with fluids and injecting them into hydraulic fractures is a well-known technology. The essence of our idea differs from conventional hydraulic fracturing techniques only slightly in that it uses fracturing fluid heavier than the surrounding rock. This difference is fundamental, however, because it allows hydraulic fractures to propagate downward and carry wastes by gravity instead of or in addition to being injected by pumping. An example of similar gravity-driven fractures with positive buoyancy is given by magmatic dikes that may serve as an analog of Abyssal Sequestration occurring in nature. Mechanics of fracture propagation in conditions of positive (diking) and negative (heavy waste slurry) buoyancy is similar and considered in this work for both cases. Analog experiments in gelatin show that fracture breadth (horizontal dimension) remains nearly stationary when fracturing process in the fracture 'head' (where breadth is 'created') is dominated by solid toughness, as opposed to the viscous fluid dissipation dominant in the fracture tail. We model propagation of the resulting 'buoyant' or 'sinking' finger-like fracture of stationary breadth with slowly varying opening along the crack length. The elastic response of the crack to fluid loading

  16. WASTE PROCESSING ANNUAL NUCLEAR SAFETY RELATED R AND D REPORT FOR CY2008

    SciTech Connect

    Fellinger, A.

    2009-10-15

    The Engineering and Technology Office of Waste Processing identifies and reduces engineering and technical risks associated with key waste processing project decisions. The risks, and actions taken to mitigate those risks, are determined through technology readiness assessments, program reviews, technology information exchanges, external technical reviews, technical assistance, and targeted technology development and deployment (TDD). The Office of Waste Processing TDD program prioritizes and approves research and development scopes of work that address nuclear safety related to processing of highly radioactive nuclear wastes. Thirteen of the thirty-five R&D approved work scopes in FY2009 relate directly to nuclear safety, and are presented in this report.

  17. Application of rock melting to construction of storage holes for nuclear waste

    SciTech Connect

    Neudecker, J.W. Jr.

    1988-12-31

    Rock melting technology can provide in-situ glass liners in nuclear waste package emplacement holes to reduce permeability and increase borehole stability. Reduction of permeability would reduce the time and probability of groundwater contacting the waste packages. Increasing the stability of the storage boreholes would enhance the retrievability of the nuclear waste packages. The rock melting hole forming technology has already been tested in volcanic tuff similar to the geology at the proposed nuclear waste repository at Yucca Mountain, Nevada. 6 refs., 5 figs., 2 tabs.

  18. Production of zinc and manganese oxide particles by pyrolysis of alkaline and Zn-C battery waste.

    PubMed

    Ebin, Burçak; Petranikova, Martina; Steenari, Britt-Marie; Ekberg, Christian

    2016-05-01

    Production of zinc and manganese oxide particles from alkaline and zinc-carbon battery black mass was studied by a pyrolysis process at 850-950°C with various residence times under 1L/minN2(g) flow rate conditions without using any additive. The particular and chemical properties of the battery waste were characterized to investigate the possible reactions and effects on the properties of the reaction products. The thermodynamics of the pyrolysis process were studied using the HSC Chemistry 5.11 software. The carbothermic reduction reaction of battery black mass takes place and makes it possible to produce fine zinc particles by a rapid condensation, after the evaporation of zinc from a pyrolysis batch. The amount of zinc that can be separated from the black mass is increased by both pyrolysis temperature and residence time. Zinc recovery of 97% was achieved at 950°C and 1h residence time using the proposed alkaline battery recycling process. The pyrolysis residue is mainly MnO powder with a low amount of zinc, iron and potassium impurities and has an average particle size of 2.9μm. The obtained zinc particles have an average particle size of about 860nm and consist of hexagonal crystals around 110nm in size. The morphology of the zinc particles changes from a hexagonal shape to s spherical morphology by elevating the pyrolysis temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Ocean storage of nuclear wastes? Experiences from the Russian Arctic.

    PubMed

    Champ, M A; Gomez, L S; Makeyev, V M; Brooks, J M; Palmer, H D; Betz, F

    2001-01-01

    An international demonstration (RD&D) project for ocean storage of radioactive wastes should be proposed, to study the feasibility of the concept of ocean storage of nuclear waste. This international project should utilize the scientific, engineering and technical capabilities of selected universities, oceanographic institutions, NGOs and industries. This project would need to be an independent (non-governmental) study, utilizing the capabilities of selected universities, oceanographic institutions, environmental NGOs (Non-Governmental Organizations) and industries. Scientists and engineers first need to conduct an engineering, environmental, and economic feasibility study of the concept. The goal of the project would be to determine if ocean-based storage reduced the risks to the environment and public health to a greater degree than land-based storage. This would require comparing the risks and factors involved and making the data and information available to anyone, anywhere, anytime on the internet. The mere presence of an investigation of the ocean storage option could facilitate scientific and engineering competition between the two options, could subsequently reduce environmental and public risks and provide better protection and cost benefits in the system utilized. One of the primary concerns of the scientific community would be related to the sensitivity and precision of the monitoring of individaul containers on the ocean bottom. An advantage of the land-based option is that if there is a release, its presence could be detected at very low levels and be contained in the storage facility. On the ocean bottom, a release from a container might not be easily detected due to dispersion. Therefore the containment system would have to be a system within a system with monitoring between the two providing greater protection. Ocean storage may have greater technical and political hurdles than land-based options, but it may provide greater protection over time

  20. A novel waste form for disposal of spent-nuclear-fuel reprocessing waste: A vitrifiable cement

    SciTech Connect

    Gougar, M.L.D.; Scheetz, B.E.; Siemer, D.D.

    1999-01-01

    A cement capable of being hot isostatically pressed into a glass ceramic has been proposed as the waste form for spent-nuclear-fuel reprocessing wastes at the Idaho National Engineering and Environmental Laboratory (INEEL). This intermediate cement, with a composition based on that of common glasses, has been designed and tested. The cement formulations included mixed INEEL wastes, blast furnace slag, reactive silica, and INEEL soil or vermiculite, which were activated with potassium or sodium hydroxide. Following autoclave processing, the cements were characterized. X-ray diffraction analysis revealed three notable crystalline phases: quartz, calcite, and fluorite. Results of compressive strength testing ranged from 1452 and 4163 psi, exceeding the US Nuclear Regulatory Commission (NRC)-suggested standard of >500 psi. From American National Standards Institute/American Nuclear Society 16.1-1986 leach testing, effective diffusivities for Cs were determined to be on the order of 10{sup {minus}11} to 10{sup {minus}10} cm{sup 2}/s and for Sr were 10{sup {minus}12} cm{sup 2}/s, which are four orders of magnitude less than diffusivities in some other radwaste materials. Average leach indices (LI) were 9.6 and 11.9 for Cs and Sr, respectively, meeting the NRC Standard of LI > 6. The 28-day Materials Characterization Center-1 leach testing resulted in normalized elemental mass losses between 0.63 and 28 g/(m{sup 2}{center_dot}day) for Cs and between 0.34 and 0.70 g/(m{sup 2}{center_dot}day) industry-accepted standard while Cs losses indicate a process sensitive parameter.

  1. Precipitation-adsorption process for the decontamination of nuclear waste supernates

    DOEpatents

    Lee, L.M.; Kilpatrick, L.L.

    1982-05-19

    High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

  2. Precipitation-adsorption process for the decontamination of nuclear waste supernates

    DOEpatents

    Lee, Lien-Mow; Kilpatrick, Lester L.

    1984-01-01

    High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

  3. CHARACTERIZATION OF DEFENSE NUCLEAR WASTE USING HAZARDOUS WASTE GUIDANCE. APPLICATIONS TO HANFORD SITE ACCELERATED HIGH-LEVEL WASTE TREATMENT AND DISPOSAL MISSION0

    SciTech Connect

    Hamel, William; Huffman, Lori; Lerchen, Megan; Wiemers, Karyn

    2003-02-27

    Federal hazardous waste regulations were developed for management of industrial waste. These same regulations are also applicable for much of the nation's defense nuclear wastes. At the U.S. Department of Energy's (DOE) Hanford Site in southeast Washington State, one of the nation's largest inventories of nuclear waste remains in storage in large underground tanks. The waste's regulatory designation and its composition and form constrain acceptable treatment and disposal options. Obtaining detailed knowledge of the tank waste composition presents a significant portion of the many challenges in meeting the regulatory-driven treatment and disposal requirements for this waste. Key in applying the hazardous waste regulations to defense nuclear wastes is defining the appropriate and achievable quality for waste feed characterization data and the supporting evidence demonstrating that applicable requirements have been met at the time of disposal. Application of a performance-based approach to demonstrating achievable quality standards will be discussed in the context of the accelerated high-level waste treatment and disposal mission at the Hanford Site.

  4. The Use of Basalt, Basalt Fibers and Modified Graphite for Nuclear Waste Repository - 12150

    SciTech Connect

    Gulik, V.I.; Biland, A.B.

    2012-07-01

    New materials enhancing the isolation of radioactive waste and spent nuclear fuel are continuously being developed.. Our research suggests that basalt-based materials, including basalt roving chopped basalt fiber strands, basalt composite rebar and materials based on modified graphite, could be used for enhancing radioactive waste isolation during the storage and disposal phases and maintaining it during a significant portion of the post-closure phase. The basalt vitrification process of nuclear waste is a viable alternative to glass vitrification. Basalt roving, chopped basalt fiber strands and basalt composite rebars can significantly increase the strength and safety characteristics of nuclear waste and spent nuclear fuel storages. Materials based on MG are optimal waterproofing materials for nuclear waste containers. (authors)

  5. Radiation effects in moist-air systems and the influence of radiolytic product formation on nuclear waste glass corrosion

    SciTech Connect

    Wronkiewicz, D.J.; Bates, J.K.; Buck, E.C.; Hoh, J.C.; Emery, J.W.; Wang, L.M.

    1997-07-01

    Ionizing radiation may affect the performance of glass in an unsaturated repository site by interacting with air, water vapor, or liquid water to produce a variety of radiolytic products. Tests were conducted to examine the effects of radiolysis under high gas/liquid ratios. Results indicate that nitrate is the predominant radiolytic product produced following both gamma and alpha radiation exposure, with lesser amounts of nitrite and carboxylic acids. The formation of nitrogen acids during exposure to long-lived, alpha-particle-emitting transuranic elements indicates that these acids may play a role in influencing nuclear waste form reactions in a long-term unsaturated disposal scenario. Experiments were also conducted with samples that simulate the composition of Savannah River Plant nuclear waste glasses. Radiolytic product formation in batch tests (340 m{sup {minus}1}, 90 C) resulted in a small increase in the release rates of many glass components, such as alkali and alkaline earth elements, although silicon and uranium release rates were slightly reduced indicating an overall beneficial effect of radiation on waste form stability. The radiolytic acids increased the rate of ion exchange between the glass and the thin film of condensate, resulting in accelerated corrosion rates for the glass. The paragenetic sequence of alteration phases formed on both the irradiated and nonirradiated glass samples reacted in the vapor hydration tests matches closely with those developed during volcanic glass alteration in naturally occurring saline-alkaline lake systems. This correspondence suggests that the high temperatures used in these tests have not changed the underlying glass reaction mechanism relate to that which controls glass reactions under ambient surficial conditions.

  6. The Nuclear Waste Technical Review Board`s views on the multipurpose canister

    SciTech Connect

    Price, D.L.

    1994-10-01

    This article presents the view of the Nuclear Waste Technical Review Board on the Multipurpose Canister (MPC). The Board believes that if developed properly the MPC has the potential for enhancing safety in the waste management system by substantially reducing handling, fostering a systems approach to the management of the nation`s spent nuclear fuel and high-level waste, and introducing a level of standardization into the system.

  7. Review of progress in the Canadian nuclear fuel waste management program

    SciTech Connect

    Lyon, R.B.; Johnson, L.H.

    1986-01-01

    The Canadian Nuclear Fuel Waste Management Program is reviewed, illustrating the progress that has been made in assessing the concept of disposal of nuclear fuel waste in plutonic rock of the Canadian Shield. Research is being conducted into used fuel storage and transportation, fuel waste immobilization, site characterization and selection methods, and performance assessment modelling. Details of achievements in these areas are outlined, and results of the most recent interim assessment are discussed.

  8. Workshop on the role of natural analogs in geologic disposal of high-level nuclear waste

    SciTech Connect

    Murphy, W.M.; Kovach, L.A.

    1995-09-01

    A workshop on the Role of Natural Analogs in Geologic Disposal of High-Level Nuclear Waste (HLW) was held in San Antonio, Texas, on July 22-25, 1991. It was sponsored by the US Nuclear Regulatory Commission (NRC) and the Center for Nuclear Waste Regulatory Analyses (CNWRA). Invitations to the workshop were extended to a large number of individuals with a variety of technical and professional interests related to geologic disposal of nuclear waste and natural analog studies. The objective of the workshop was to examine the role of natural analog studies in performance assessment, site characterization, and prioritization of research related to geologic disposal of HLW.

  9. Investigation on application of homogeneous and heterogeneous catalysis for alkaline waste treatment

    SciTech Connect

    Shilov, V.P.; Bessonov, A.A.; Garnov, A.Y.; Gelis, A.V.

    1997-09-01

    The stabilization of neptunium(IV) in alkaline solution by chemical reductants under various conditions was studied. Testing showed that neptunium(V) is slowly reduced to Np(IV) by V(IV) at room temperature in alkaline solutions. Increasing temperature accelerates reduction. Complete reduction of 2 x 10{sup -4} M Np(V) occurs in three hours at 80{degrees}C in 1 M NaOH with 0.02 M VOSO{sub 4-}. Under similar conditions, but in 5 M NaOH, only 15 to 20% of the Np(V) was reduced in 5 hours. In all cases, about 98 % of the initial neptunium was found in the precipitate. Thus V(IV) acts both as a reductant and as a precipitation carrier. Tests showed Np(V) reduction by hydrazine hydrate could be catalyzed by Pd(II). Reduction increased with temperature and catalyst concentration and decreased with hydroxide concentration. Reduction of Np(V) also takes place in 1 M NaOH solutions containing 1 M sodium formate and palladium. Increasing temperature accelerates reduction; with three hours` treatment in 5 M NaOH solution at 90{degrees}C, about 95 % of the initial 2 x 10{sup -4} M neptunium(V) is transformed to Np(IV). Organic complexants and organic acid anions hinder the decontamination of alkaline solutions from neptunium and plutonium by coprecipitation with d-element hydroxides (the Method of Appearing Reagents). It was found that ethylenediaminetetraacetate (EDTA) and N-(2-hydroxyethyl) ethylenediaminetriacetate (HEDTA) are decomposed by H{sub 2}O{sub 2} in alkaline solution in the presence of cobalt compounds with heating and by Na2S208 at moderate temperatures. Citrate, glycolate, and oxalate are decomposed by Na{sub 2}S{sub 2}O{sub 8} with heating. Oxidant amounts must be increased when NaNO{sub 2} also is present in solution. 8 refs., 25 figs., 16 tabs.

  10. Reframing nuclear power in the UK energy debate: nuclear power, climate change mitigation and radioactive waste.

    PubMed

    Bickerstaff, K; Lorenzoni, I; Pidgeon, N F; Poortinga, W; Simmons, P

    2008-04-01

    In the past decade, human influence on the climate through increased use of fossil fuels has become widely acknowledged as one of the most pressing issues for the global community. For the United Kingdom, we suggest that these concerns have increasingly become manifest in a new strand of political debate around energy policy, which reframes nuclear power as part of the solution to the need for low-carbon energy options. A mixed-methods analysis of citizen views of climate change and radioactive waste is presented, integrating focus group data and a nationally representative survey. The data allow us to explore how UK citizens might now and in the future interpret and make sense of this new framing of nuclear power--which ultimately centers on a risk-risk trade-off scenario. We use the term "reluctant acceptance" to describe how, in complex ways, many focus group participants discursively re-negotiated their position on nuclear energy when it was positioned alongside climate change. In the concluding section of the paper, we reflect on the societal implications of the emerging discourse of new nuclear build as a means of delivering climate change mitigation and set an agenda for future research regarding the (re)framing of the nuclear energy debate in the UK and beyond.

  11. EXPERIMENTAL METHODS TO ESTIMATE ACCUMULATED SOLIDS IN NUCLEAR WASTE TANKS

    SciTech Connect

    Duignan, M.; Steeper, T.; Steimke, J.

    2012-12-10

    The Department of Energy has a large number of nuclear waste tanks. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles, e.g., plutonium containing, could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids and supernatant were charged to the test tank and rotating liquid jets were used to remove most of the solids. Then the volume and shape of the residual solids and the spatial concentration profiles for the surrogate for plutonium were measured. This paper discusses the overall test results, which indicated heavy solids only accumulate during the first few transfer cycles, along with the techniques and equipment designed and employed in the test. Those techniques include: Magnetic particle separator to remove stainless steel solids, the plutonium surrogate from a flowing stream; Magnetic wand used to manually remove stainless steel solids from samples and the tank heel; Photographs were used to determine the volume and shape of the solids mounds by developing a composite of topographical areas; Laser rangefinders to determine the volume and shape of the solids mounds; Core sampler to determine the stainless steel solids distribution within the solids mounds; Computer driven positioner that placed the laser rangefinders and the core sampler over solids mounds that accumulated on the bottom of a scaled staging tank in locations where jet velocities were low. These

  12. Nuclear energy and waste management pyroprocess for system symbiosis

    NASA Astrophysics Data System (ADS)

    Ogawa, Toru; Minato, Kazuo; Okamoto, Yoshihiro; Nishihara, Kenji

    2007-01-01

    The actinide management has become a key issue in nuclear energy. Recovering and fissioning transuranium elements reduce the long-term proliferation risks and the environmental burden. The better way of waste management will be made by system symbiosis: a combination of light-water reactor and fast reactor and/or accelerator-driven transmutation system should be sought. The new recycling technology should be able to achieve good economy with smaller plants, which can process fuels from different types of reactors on a common technical basis. Ease in handling the higher heat load of transuranium nuclides is also important. Pyroprocesses with the use of molten salts are regarded as the strong candidate for such recycling technology. In JAEA, the first laboratory for the high-temperature chemistry of Am and Cm has been established. The fundamental data will be combined with the computer code for predicting the molten-salts electrolytic processes.

  13. Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

    SciTech Connect

    R.B. Rebak

    2006-08-28

    Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories, alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking.

  14. Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

    SciTech Connect

    Rebak, R B

    2006-06-01

    Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking.

  15. Environmental Degradation of Materials for Nuclear Waste Repositories Engineered Barriers

    SciTech Connect

    Rebak, R B

    2006-12-24

    Several countries are considering geological repositories for the storage of nuclear waste. Most of the environments for these repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories, alloys such as carbon steel, copper, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking.

  16. Determination of 36Cl in nuclear waste from reactor decommissioning.

    PubMed

    Hou, Xiaolin; Ostergaard, Lars Frøsig; Nielsen, Sven P

    2007-04-15

    An analytical method for the determination of 36Cl in nuclear waste such as graphite, heavy concrete, steel, aluminum, and lead was developed. Several methods were investigated for decomposing the samples. AgCl precipitation was used to separate 36Cl from the matrix elements, followed by ion-exchange chromatography to remove interfering radionuclides. The purified 36Cl was then measured by liquid scintillation counting. The chemical yield of chlorine, as measured by ICPMS, is above 70% and the decontamination factors for all interfering radionuclides are greater than 10(6). The detection limit of this analytical method for 36Cl is 14 mBq. The method has been used to determine 36Cl in heavy concrete, aluminum, and graphite from the Danish DR-2 research reactor.

  17. Geotechnical support and topical studies for nuclear waste geologic repositories

    SciTech Connect

    Not Available

    1989-01-01

    The present report lists the technical reviews and comments made during the fiscal year 1988 and summarizes the technical progress of the topical studies. In the area of technical assistance, there were numerous activities detailed in the next section. These included 24 geotechnical support activities, including reviews of 6 Study Plans (SP) and participation in 6 SP Review Workshops, review of one whole document Site Characterization Plan (SCP) and participation in the Assembled Document SCP Review Workshops by 6 LBL reviewers; the hosting of a DOE program review, the rewriting of the project statement of work, 2 trips to technical and planning meetings; preparation of proposed work statements for two new topics for DOE, and 5 instances of technical assistance to DOE. These activities are described in a Table in the following section entitled Geoscience Technical Support for Nuclear Waste Geologic Repositories.''

  18. WASTE ISOLATION PILOT PLANT (WIPP): THE NATIONS' SOLUTION TO NUCLEAR WASTE STORAGE AND DISPOSAL ISSUES

    SciTech Connect

    Lopez, Tammy Ann

    2014-07-17

    In the southeastern portion of my home state of New Mexico lies the Chihuahauan desert, where a transuranic (TRU), underground disposal site known as the Waste Isolation Pilot Plant (WIPP) occupies 16 square miles. Full operation status began in March 1999, the year I graduated from Los Alamos High School, in Los Alamos, NM, the birthplace of the atomic bomb and one of the nation’s main TRU waste generator sites. During the time of its development and until recently, I did not have a full grasp on the role Los Alamos was playing in regards to WIPP. WIPP is used to store and dispose of TRU waste that has been generated since the 1940s because of nuclear weapons research and testing operations that have occurred in Los Alamos, NM and at other sites throughout the United States (U.S.). TRU waste consists of items that are contaminated with artificial, man-made radioactive elements that have atomic numbers greater than uranium, or are trans-uranic, on the periodic table of elements and it has longevity characteristics that may be hazardous to human health and the environment. Therefore, WIPP has underground rooms that have been carved out of 2,000 square foot thick salt formations approximately 2,150 feet underground so that the TRU waste can be isolated and disposed of. WIPP has operated safely and successfully until this year, when two unrelated events occurred in February 2014. With these events, the safety precautions and measures that have been operating at WIPP for the last 15 years are being revised and improved to ensure that other such events do not occur again.

  19. Identifying suitable "piercement" salt domes for nuclear waste storage sites

    SciTech Connect

    Kehle, R.

    1980-08-01

    Piercement salt domes of the northern interior salt basins of the Gulf of Mexico are being considered as permanent storage sites for both nuclear and chemically toxic wastes. The suitable domes are stable and inactive, having reached their final evolutionary configuration at least 30 million years ago. They are buried to depths far below the level to which erosion will penetrate during the prescribed storage period and are not subject to possible future reactivation. The salt cores of these domes are themselves impermeable, permitting neither the entry nor exit of ground water or other unwanted materials. In part, a stable dome may be recognized by its present geometric configuration, but conclusive proof depends on establishing its evolutionary state. The evolutionary state of a dome is obtained by reconstructing the growth history of the dome as revealed by the configuration of sedimentary strata in a large area (commonly 3,000 square miles or more) surrounding the dome. A high quality, multifold CDP reflection seismic profile across a candidate dome will provide much of the necessary information when integrated with available subsurface control. Additional seismic profiles may be required to confirm an apparent configuration of the surrounding strata and an interpreted evolutionary history. High frequency seismic data collected in the near vicinity of a dome are also needed as a supplement to the CDP data to permit accurate depiction of the configuration of shallow strata. Such data must be tied to shallow drill hole control to confirm the geologic age at which dome growth ceased. If it is determined that a dome reached a terminal configuration many millions of years ago, such a dome is incapable of reactivation and thus constitutes a stable storage site for nuclear wastes.

  20. Commercial US nuclear reactors and waste: the current status

    SciTech Connect

    Platt, A.M.; Robinson, J.V.

    1980-09-01

    Between March 1 and June 15, 1980, the declared size of the commercial light waste reactor (LWR) nuclear power industry in the US has decreased another 9 GWe. For the presently declared size: the 165 declared reactors will peak at a capacity of 153 GWe in 2001 and will consume about 870,000 MTU as enrichment feed; the theoretical rate of enrichment requirements will peak at about 19,000,000 SWUs/y in the year 2014; as few as two repositories each with capacity equivalent to 100,000 MTU would hold the waste; and predisposal storage reactor basins and AFRs (away-from-reactor basins) would peak at <85,000 MTU in the year 2020 if the two respositories were commissioned in the years 1997 and 2020. It should be noted that the number of declared LWRs has dropped from 226 on December 31, 1974 to 165 as of this writing. The oil equivalent of the energy loss, assuming a 50% efficiency in use as in cars, is 17,000 million barrels. This is about 10 years of the current rate of US consumption of OPEC oil.

  1. Redox reaction and foaming in nuclear waste glass melting

    SciTech Connect

    Ryan, J.L.

    1995-08-01

    This document was prepared by Pacific Northwest Laboratory (PNL) and is an attempt to analyze and estimate the effects of feed composition variables and reducing agent variables on the expected chemistry of reactions occurring in the cold cap and in the glass melt in the nuclear waste glass Slurry-fed, joule-heated melters as they might affect foaming during the glass-making process. Numerous redox reactions of waste glass components and potential feed additives, and the effects of other feed variables on these reactions are reviewed with regard to their potential effect on glass foaming. A major emphasis of this report is to examine the potential positive or negative aspects of adjusting feed with formic acid as opposed to other feed modification techniques including but not limited to use of other reducing agents. Feed modification techniques other than the use of reductants that should influence foaming behavior include control of glass melter feed pH through use of nitric acid. They also include partial replacement of sodium salts by lithium salts. This latter action (b) apparently lowers glass viscosity and raises surface tension. This replacement should decrease foaming by decreasing foam stability.

  2. Nuclear waste management issues: a multidisciplinary evaluation framework.

    SciTech Connect

    Hoffman, M.

    1980-02-01

    Initially, this paper characterizes the nuclear waste problem that requires analysis to establish the rationale for an interdisciplinary approach to resolve it. The problem characterization also explains why the specific concern with contaminated groundwater and intrusion through drilling has been selected for the focus of the panel meeting. The Nominal Group Technique (NGT), the group process format chosen for the experts' deliberations, is explained in some detail and its value in facilitating the desired dialogue is described. The dialogue is organized around the various issue areas that would be of concern to a program manager dealing with the potential problem of radioactivity escaping to the biosphere through human intrusion into contaminated groundwater. The participants are identified by professional discipline so that the dialogue can be presented in a realistic fashion. Both the content of the dialogue and its format are evaluated. Particular attention is given to their usefulness in generating a cross-section of subissues and factors that should be addressed when analyzing the waste disposal system's adequacy to prevent contaminated groundwater escaping to the biosphere.

  3. Status of the Canadian nuclear fuel waste management program

    SciTech Connect

    Allan, C.J.; Stephens, M.E. )

    1992-01-01

    The Canadian Concept for the permanent disposal of nuclear fuel waste has been developed extensively over the past several years, and is now well-advanced. The Concept, which involves the construction of a waste vault 500 to 1000 metres deep in plutonic rock located in the Canadian Precambrian Shield, is supported by an R D program with the following objectives: (1) to develop and demonstrate technology to site, design, build and operate a disposal facility; (2) to develop and demonstrate a methodology to evaluate the performance of the disposal system; and (3) to demonstrate that sites are likely to exist in the Canadian Precambrian Shield that would meet the regulatory requirements. A combination of engineered and natural barriers will be used to ensure that the vault design will meet rigorous safety standards. Experimental work is being carried out to elucidate all the important phenomena associated with the safety of the vault, including the performance of engineered barriers, natural geological barriers, and the biosphere.

  4. Commercial nuclear reactors and waste: the current status

    SciTech Connect

    Platt, A.M.; Robinson, J.V.

    1980-04-01

    During the last five years, the declared size of the commercial light water reactor (LWR) nuclear power industry in the US has steadily decreased. As of January 1980, the total number of power plants had dropped to 191 from the 226 in December 31, 1974. At least another nine were cancelled in the last few months. This report was developed as the first of a series to track implications to waste management due to such changes in the declared size of the industry. For the presently declared size, key conclusions are: the declared reactors will peak at a capacity of 162 GWe and consume about 10/sup 6/ MTU as enrichment feed. As few as two repositories of about 100,000 MTHM capacity each would hold the waste. Predisposal storage (reactor basins and AFRs) would peak at less than 100,000 MTHM (in the year 2020) with one repository opening in the year 1997 and the other in the year 2020. Most of the 100,000 MTHM would have to be in AFR storage unless current practice regarding reactor basin size was radically changed.

  5. Ceramic package fabrication for YMP nuclear waste disposal

    SciTech Connect

    Wilfinger, K.

    1994-08-01

    The purpose of this work is to develop alternate materials/design concepts to metal barriers for the Nevada Nuclear Waste Storage Investigations Project. There is some potential that site conditions may prove to be too aggressive for successful employment of the metal alloys under current consideration or that performance assessment models will predict metal container degradation rates that are inconsistent with the goal of substantially complete containment included in the NRC regulations. In the event that the anticipated lifetimes of metal containers are considered inadequate, alternate materials (i.e. ceramics or ceramic/metal composites) will be chosen due to superior corrosion resistance. This document was prepared using information taken from the open literature, conversations and correspondence with vendors, news releases and data presented at conferences to determine what form such a package might take. This discussion presents some ceramic material selection criteria, alternatives for the materials which might be used and alternatives for potential fabrication routes. This includes {open_quotes}stand alone{close_quotes} ceramic components and ceramic coatings/linings for metallic structures. A list of companies providing verbal or written information concerning the production of ceramic or ceramic lined waste containers appears at the end of this discussion.

  6. Bare Fiber Bragg Gratings embedded into concrete buffer Supercontainer concept for nuclear waste storage [ANIMMA--2015-IO-337

    SciTech Connect

    Kinet, Damien; Chah, Karima; Megret, Patrice; Caucheteur, Christophe; Gusarov, Andrei; Faustov, Alexey; Areias, Lou

    2015-07-01

    Nuclear power plants have been generating electricity for more than 50 years. In Belgium, 55% of the current energy supply comes from nuclear power. Providing for the safe storage of nuclear waste, including spent fuel (SF) and vitrified high level radioactive waste (HLW), remains an important challenge in the life cycle of nuclear fuel. In this context, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials (ONDRAF/NIRAS) is investigating a reference conceptual design called the Supercontainer (SC) for the packaging of SF and HLW. This conceptual design is based on a multiple-barrier system consisting of a hermetically-sealed carbon steel overpack and a surrounding highly-alkaline concrete buffer. The first one is developed to retain the radionuclides. The two main functions of the buffer are (a) to create a high pH environment around the carbon steel overpack in order to passivate the metal surface and so to slow down the corrosion propagation during the thermal phase and (b) to provide a radiological shielding during the construction and the handling of the Supercontainer. A recent test has been performed to investigate the feasibility to construct the SC. This test incorporated several kinds of sensors including Digital Image Correlation (DIC), Acoustic Emission (AE), corrosion sensing techniques and optical fibers with and without fiber Bragg gratings (FBGs). In particular, several single-mode optical fibers with 4 mm long FBGs with different Bragg wavelengths and distributed along the optical fibers were used. For casting and curing condition monitoring, a number of gratings were incorporated inside the concrete buffer during the first stage of construction. Then other sensors were embedded near a heat source installed in the second stage to simulate the effects of heat generated by radioactive waste. The FBGs were designed to measure both temperature and strain effects in the concrete. To discriminate between these effects special packaging

  7. Alkaline pretreatment improves saccharification and ethanol yield from waste money bills.

    PubMed

    Sheikh, Md Mominul Islam; Kim, Chul-Hwan; Park, Hyeon-Jin; Kim, Sung-Ho; Kim, Gyeong-Chul; Lee, Ji-Young; Sim, Sung-Woong; Kim, Jae Won

    2013-01-01

    Waste money bills (WMB) is a by-product of the money making process that consists of rich-cellulosic material for many biotechnological applications. This waste money bills is unusable and usually exhausted. Saccharification was improved using various concentrations of sodium hydroxide, NaOH (0.0, 0.5, 1.0, 2.0, 2.5, and 3.0% v/v) and various reaction times (20, 30, and 40 min) during pretreatment at 121 °C. Prior to ethanol fermentation, the highest glucose yield (62.2 mg/mL) was found by pretreatment consisting of 30 min at 2.0% NaOH, and it increased 33.8% as compared to an untreated sample. The highest amount of ethanol was obtained (26.1 mg/mL) during fermentation, and this was increased 95.3 and 22.5% as compared to aerobic and anaerobic conditions respectively during pretreatment with 2.0% NaOH for 30 min. Under anaerobic conditions, ethanol fermentation was enhanced by adding 0.4 mmol benzoic acid. Production of ethanol from waste money bills would cut waste management costs and make profitable.

  8. Transesterification of waste cooking oil by an organic solvent-tolerant alkaline lipase from Streptomyces sp. CS273.

    PubMed

    Mander, Poonam; Yoo, Hah-Young; Kim, Seung Wook; Choi, Yun Hee; Cho, Seung Sik; Yoo, Jin Cheol

    2014-02-01

    The aim of this present study was to produce a microbial enzyme that can potentially be utilized for the enzymatic transesterification of waste cooking oil. To that end, an extracellular lipase was isolated and purified from the culture broth of Streptomyces sp. CS273. The molecular mass of purified lipase was estimated to be 36.55 kDa by SDS PAGE. The optimum lipolytic activity was obtained at alkaline pH 8.0 to 8.5 and temperature 40 °C, while the enzyme was stable in the pH range 7.0 ∼ 9.0 and at temperature ≤40 °C. The lipase showed highest hydrolytic activity towards p-nitrophenyl myristate (C14). The lipase activity was enhanced by several salts and detergents including NaCl, MnSo₄, and deoxy cholic acid, while phenylmethylsulfonyl fluoride at concentration 10 mM inhibited the activity. The lipase showed tolerance towards different organic solvents including ethanol and methanol which are commonly used in transesterification reactions to displace alcohol from triglycerides (ester) contained in renewable resources to yield fatty acid alkyl esters known as biodiesel. Applicability of the lipase in transesterification of waste cooking oil was confirmed by gas chromatography mass spectrometry analysis.

  9. 76 FR 3678 - Board Meeting: February 16, 2011-Las Vegas, NV, the U.S. Nuclear Waste Technical Review Board...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ... Radioactive Waste Pursuant to its authority under section 5051 of Public Law 100-203, Nuclear Waste Policy...) activities related to managing and disposing of spent nuclear fuel and high-level radioactive waste. The... repository for spent fuel and high-level radioactive waste over the last two decades. The Board also will...

  10. Reduction of Sodium Nitrate Liquid Waste in Nuclear Reprocessing Plants

    SciTech Connect

    Numata, M.; Mihara, S.; Kojima, S.; Ito, H.; Kato, T.

    2006-07-01

    Sodium nitrate solution has been generated from nuclear reprocessing plant as a result of neutralization of nitric acid. The sodium nitrate has been immobilized by bitumen, cement or other material in the site and waste packages have been produced. In order to reduce an environmental impact of the waste packages from the reprocessing plant, it is preferable to decompose nitrate ion to harmless gases such as nitrogen. A combination of formic acid and catalyst has been proposed for this purpose. But, the method is inadequate for a full decomposition of the nitrate ion. In addition, a mixture of NO and NO{sub 2} is produced during the reaction. Formaldehyde and hydrazine were selected as reductants and a combined use of Pd-Cu catalyst was tried to decompose the nitrate ion. As a result, the nitrate ion can almost entirely be decomposed without any generation of NO and NO{sub 2}. The test was conducted by 1 L flask. In case of formaldehyde, nitrate ion concentration can be reduced from 0.017 mol/l to 3.9x10{sup -4} mol/l. In case of hydrazine, nitrate concentration can be decreased from 2.8 mol/l to 9.5 x 10{sup -3} mol/l and ammonium ion is detected. The ammonium ion concentration in the final solution is 0.12 mol/l when 2.8 mol/l nitrate is reduced by hydrazine. Chemical reactions for formaldehyde on the Pd-Cu catalyst are estimated as combination of: NO{sub 3-} + HCHO = NO{sub 2-} + HCOOH; 2NO{sub 2-} + 3HCOOH = N{sub 2} + 3CO{sub 2} + 2H{sub 2}O + 2OH-; 4NO{sub 2-} + 3HCHO = 2N{sub 2} + 3CO{sub 2} + H{sub 2}O + 4OH-. the other hand, for hydrazine with the Pd-Cu catalyst: 3N{sub 2}H{sub 4} = 2NH{sub 3} + 2N{sub 2} + 3H{sub 2}; NO{sub 3-} + H{sub 2} = NO{sub 2-} + H{sub 2}O; NO{sub 2-} + NH{sub 3} = N{sub 2} + H{sub 2}O + OH-. The fundamental research shows that the combination usage of the Pd-Cu catalyst and formaldehyde or hydrazine is applicable for the reduction of nitrate liquid waste in the nuclear reprocessing plant. (authors)

  11. Remote installation of risers on underground nuclear waste storage tanks

    SciTech Connect

    Jackson, J.P.; Gessner, R.F.

    1988-03-01

    The West Valley Demonstration Project was established to solidify 2120 m/sup 3/ (560,000) gallons of high-level nuclear waste generated during six years of commercial nuclear fuel reprocessing. This liquid will be processed to remove radioactive elements which, with the remaining sludge, will be combined with glass formers and be converted into borosilicate glass. Risers were installed on the high-level tank for installation of pumps which will be used to remove the liquid and sludge. The extensive use of remote technology was required to install the risers and to minimize operator exposure to high levels of radiation and contamination. The riser installation required remotely: drilling through two feet of concrete shielding; installing pump access pipes which are welded to the tank top; and cutting holes in tanks located 3658 mm (12) feet below ground. These operations were successfully completed 13 times without exposing personnel to high-level radiation or contamination. Specially designed remote equipment was developed for each step of this operation. Extensive operator training in the use of this equipment was performed on a tank with low radiation prior to work on the high-level tank. This paper discusses the application of remote technology that assured a quality job was safely accomplished. 3 refs., 18 figs., 2 tabs.

  12. Microbial studies in the Canadian nuclear fuel waste management program.

    PubMed

    Stroes-Gascoyne, S; West, J M

    1997-07-01

    Atomic Energy of Canada Limited (AECL) has developed a concept for permanent geological disposal of used nuclear fuel in Canada. This concept, based on a multibarrier system, would involve disposal of nuclear fuel waste in titanium or copper containers, surrounded by compacted clay-based buffer and backfill materials, in a vault 500-1000 m deep in granitic rock of the Canadian Shield. Subsurface environments will not be sterile and an experimental program was initiated in 1991 by AECL to address and quantify the potential effects of microbial action on the integrity of the disposal vault. This microbial program focuses on answering specific questions in areas such as the survival of bacteria in compacted clay-based buffer materials under relevant radiation, temperature and desiccation conditions; mobility of microbes in compacted buffer materials; the potential for microbially influenced corrosion of containers; microbial gas production in backfill material; introduction of nutrients as a result of vault excavation and operation; the presence and activity of microbes in deep granitic groundwaters; and the effects of biofilms on radionuclide migration in the geosphere. This paper summarizes the results to date from the research activities at AECL.

  13. Compton Radiation for Nuclear Waste Management and Transmutation

    NASA Astrophysics Data System (ADS)

    Bulyak, E.; Urakawa, J.

    2015-10-01

    Compton inverse radiation is emitted in the process of backscattering of the laser pulses off the relativistic electrons. This radiation possesses high spectral density and high energy of photons--in hard x-ray up to gammaray energy range--with moderate electron energies (hundreds of MeV up to 1 GeV) due to short wavelength of the laser radiation. The Compton radiation is well collimated: emitting within a narrow cone along the electron beam. A distinct property of the Compton inverse radiation is a steep high-energy cutoff of the spectrum and the maximal intensity just below the cutoff. The Compton sources can attain: spectral density up to 1014 gammas/(s 0.1%bandwidth) in MeV range of energies, and spectral brightness up to 1020 gammas/(smm2mr2 0.1% bw). Applicability of Compton sources for nuclear waste management and detection of radioisotopes and fissionable nuclides are discussed in the report. Also application limits of Compton gamma sources for transmutation of radioactive isotopes are estimated. A recently proposed subtracting method, in which two sets of data obtained by irradiating the object by the Compton beams with slightly different maximal energies are compared, will enhance resolution of detection radioactive elements at the 'atomic' (hundreds of keV) and the 'nuclear' (a few MeV) photon energies.

  14. The durability of single, dual, and multiphase titanate ceramic waste forms for nuclear waste immobilization

    NASA Astrophysics Data System (ADS)

    Harkins, Devin J. H.

    A significant amount of the energy used in the United States comes from nuclear power, which produces a large amount of waste materials. Recycling nuclear waste is possible, but requires a way to permanently fix the unusable radionuclides remaining from the recycling process in a stable, leach resistant structure. Multiphase titanate ceramic waste forms are one promising option under consideration. However, there is insufficient work on the long term corrosion of the individual phases, as well as the multiphase systems of these ceramics. These multiphase titanate ceramic waste forms have three targeted phases: hollandite, pyrochlore, and zirconolite. Hollandite is a promising candidate for the incorporation of Cs, while pyrochlore is readily formed with lanthanides, such as Nd, the most prevalent lanthanide in the waste stream. The third targeted phase, zirconolite, is for the incorporation of zirconium and the actinides. This work looks into the formation of single phase systems of lanthanide titanates, formation of dual phase systems of Ga doped Ba hollandites and Nd titanate, durability of single phase hollandites and multiphase model systems using Vapor Hydration Testing (ASTM C 1663-09), dissolution of dual phase systems of Ga doped Ba hollandites and Nd titanate using Product Consistency Testing (ASTM C 1285-02), as well investigating how grain size affects amount of alterative phases formed using Vapor Hydration Testing. The dual phase systems of hollandites and Nd titanate show significant amounts of secondary phases forming, heavily influenced by the composition of hollandite used in the systems. The most significant phase present was BaNd2Ti5O14. This phase proves to be problematic due to the degradation to the hollandite structure. Using Vapor Hydration Testing to investigate single and multiphase systems presented many some possible alteration phases that could occur in the long term aging of these ceramics. Most notably, Cs rich phases were found in

  15. Feasibility of Lateral Emplacement in Very Deep Borehole Disposal of High Level Nuclear Waste

    DTIC Science & Technology

    2010-06-01

    Boiling Water Reactor (BWR) assemblies. 1.3 Overview of the Deep Borehole Concept 1.3.1 Nuclear Waste Any national nuclear waste repository must be...Dept. of Nuclear Science and Engineering, September 2004. 2 “Light-Water Reactor Fuel,” Nuclear Fuel Industries, 2010, Accessed 7 May 2010 at http...Report TM- 63 Jer 010 at 1965, pg. 352. d, pg. 354. 62 Charles W. Fo System for Spent- Nuclear Fuel (SNF) and its Applicability to Lightwater Reactor

  16. SOLUBILITY OF URANIUM AND PLUTONIUM IN ALKALINE SAVANNAH RIVER SITE HIGH LEVEL WASTE SOLUTIONS

    SciTech Connect

    King, W.; Hobbs, D.; Wilmarth, B.; Edwards, T.

    2010-03-10

    Five actual Savannah River Site tank waste samples and three chemically-modified samples were tested to determine solubility limits for uranium and plutonium over a one year time period. Observed final uranium concentrations ranged from 7 mg U/L to 4.5 g U/L. Final plutonium concentrations ranged from 4 {micro}g Pu/L to 12 mg Pu/L. Actinide carbonate complexation is believed to result in the dramatic solubility increases observed for one sample over long time periods. Clarkeite, NaUO{sub 2}(O)OH {center_dot} H{sub 2}O, was found to be the dominant uranium solid phase in equilibrium with the waste supernate in most cases.

  17. Behavior of mercury and iodine during vitrification of simulated alkaline Purex waste

    SciTech Connect

    Holton, L.K.

    1981-09-01

    Current plans indicate that the high-level wastes stored at the Savannah River Plant will be solidified by vitrification. The behavior of mercury and iodine during the vitrification process is of concern because: mercury is present in the waste in high concentrations (0.1 to 2.8 wt%); mercury will react with iodine and the other halogens present in the waste during vitrification and; the mercury compounds formed will be volatilized from the vitrification process placing a high particulate load in the vitrification system off-gas. Twelve experiments were completed to study the behavior of mercury during vitrification of simulated SRP Purex waste. The mercury was completely volatized from the vitrification system in all experiments. The mercury reacted with iodine, chlorine and oxygen to form a fine particulate solid. Quantitative recovery of mercury compounds formed in the vitrification system off-gas was not possible due to high (37 to 90%) deposition of solids in the off-gas piping. The behavior of mercury and iodine was most strongly influenced by the vitrification system atmosphere. During experiments performed in which the oxygen content of the vitrification system atmosphere was low (< 1 vol%); iodine retention in the glass product was 27 to 55%, the mercury composition of the solids recovered from the off-gas scrub solutions was 75 to 85 wt%, and a small quantity of metallic mercury was recovered from the off-gas scrub solution. During experiments performed in which the oxygen content of the vitrification system atmosphere was high (20 vol%), iodide retention in the glass product was 3 to 15%, the mercury composition of the solids recovered from the off-gas scrub solutions was 60 to 80 wt%, and very little metallic mercury was recovered from the off-gas scrub solution.

  18. Characterization and inventories of nuclear materials and wastes for possible future energy scenarios

    SciTech Connect

    Arthur, E.D.

    1997-10-01

    Awareness of the total materials inventory and materials balance associated with differing methods for energy generation is part of present day concerns associated with disparate areas that include atmospheric emissions, resource utilization, health effects, and both current and long term hazards and risks. Nuclear energy, for a number of decades, has been the recipient of significant scrutiny concerning the materials and wastes it generates, particularly in the context of long term solutions to such issues. This paper examines the nuclear materials and waste generation for nuclear energy scenarios spanning the coming century. The paper also briefly addresses wastes (in the form of emissions) from other energy sources and examines requirements associated with backend energy system materials management. Possible future requirements pertaining to CO{sub 2} management are found to place conditions upon waste management generally similar to those for nuclear waste. One example of material flows for the case of coal generation of electricity coupled with carbon sequestration is also given.

  19. On-site storage of high level nuclear waste: attitudes and perceptions of local residents.

    PubMed

    Bassett, G W; Jenkins-Smith, H C; Silva, C

    1996-06-01

    No public policy issue has been as difficult as high-level nuclear waste. Debates continue regarding Yucca Mountain as a disposal site, and-more generally-the appropriateness of geologic disposal and the need to act quickly. Previous research has focused on possible social, political, and economic consequences of a facility in Nevada. Impacts have been predicted to be potentially large and to emanate mainly from stigmatization of the region due to increased perceptions of risk. Analogous impacts from leaving waste at power plants have been either ignored or assumed to be negligible. This paper presents survey results on attitudes of residents in three counties where nuclear waste is currently stored. Topics include perceived risk, knowledge of nuclear waste and radiation, and impacts on jobs, tourism, and housing values from leaving waste on site. Results are similar to what has been reported for Nevada; the public is concerned about possible adverse effects from on-site storage of waste.

  20. Debate heats up over potential Interim Nuclear Waste Repository, as studies of Yucca Mountain continue

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    With spent nuclear fuel piling up at power plants around the United States, and with a potential permanent nuclear waste repository at Nevada's Yucca Mountain not scheduled to accept waste until 11 years from now in the year 2010, the nuclear energy industry and many members of Congress have renewed their push to establish an interim repository at the adjacent Nevada Test Site of nuclear bombs.At a sometimes contentious March 12 hearing to consider the Nuclear Waste Policy Act of 1999 (House Resolution 45) that would require an interim facility to begin accepting waste in 2003, bill cosponsor Rep. Jim Barton (R-Tex.) told Energy Secretary Bill Richardson that he preferred that Congress and the Clinton Administration negotiate rather than fight over the measure.

  1. Nuclear energy and radioactive waste disposal in the age of recycling

    SciTech Connect

    Conca, James L.; Apted, Michael

    2007-07-01

    The magnitude of humanity's energy needs requires that we embrace a multitude of various energy sources and applications. For a variety of reasons, nuclear energy must be a major portion of the distribution, at least one third. The often-cited strategic hurdle to this approach is nuclear waste disposal. Present strategies concerning disposal of nuclear waste need to be changed if the world is to achieve both a sustainable energy distribution by 2040 and solve the largest environmental issue of the 21. century - global warming. It is hoped that ambitious proposals to replace fossil fuel power generation by alternatives will drop the percentage of fossil fuel use substantially, but the absolute amount of fossil fuel produced electricity must be kept at or below its present 10 trillion kW-hrs/year. Unfortunately, the rapid growth in consumption to over 30 trillion kW-hrs/year by 2040, means that 20 trillion kW-hrs/yr of non-fossil fuel generated power has to come from other sources. If half of that comes from alternative non-nuclear, non-hydroelectric sources (an increase of 3000%), then nuclear still needs to increase by a factor of four worldwide to compensate. Many of the reasons nuclear energy did not expand after 1970 in North America (proliferation, capital costs, operational risks, waste disposal, and public fear) are no longer a problem. The WIPP site in New Mexico, an example of a solution to the nuclear waste disposal issue, and also to public fear, is an operating deep geologic nuclear waste repository in the massive bedded salt of the Salado Formation. WIPP has been operating for eight years, and as of this writing, has disposed of over 50,000 m{sup 3} of transuranic waste (>100 nCi/g but <23 Curie/liter) including high activity waste. The Salado Formation is an ideal host for any type of nuclear waste, especially waste from recycled spent fuel. (authors)

  2. Decommissioning and Dismantling of Liquid Waste Storage and Liquid Waste Treatment Facility from Paldiski Nuclear Site, Estonia

    SciTech Connect

    Varvas, M.; Putnik, H.; Johnsson, B.

    2006-07-01

    The Paldiski Nuclear Facility in Estonia, with two nuclear reactors was owned by the Soviet Navy and was used for training the navy personnel to operate submarine nuclear reactors. After collapse of Soviet Union the Facility was shut down and handed over to the Estonian government in 1995. In co-operation with the Paldiski International Expert Reference Group (PIERG) decommission strategy was worked out and started to implement. Conditioning of solid and liquid operational waste and dismantling of contaminated installations and buildings were among the key issues of the Strategy. Most of the liquid waste volume, remained at the Facility, was processed in the frames of an Estonian-Finnish co-operation project using a mobile wastewater purification unit NURES (IVO International OY) and water was discharged prior to the site take-over. In 1999-2002 ca 120 m{sup 3} of semi-liquid tank sediments (a mixture of ion exchange resins, sand filters, evaporator and flocculation slurry), remained after treatment of liquid waste were solidified in steel containers and stored into interim storage. The project was carried out under the Swedish - Estonian co-operation program on radiation protection and nuclear safety. Contaminated installations in buildings, used for treatment and storage of liquid waste (Liquid Waste Treatment Facility and Liquid Waste Storage) were then dismantled and the buildings demolished in 2001-2004. (authors)

  3. Nuclear waste management. Semiannual progress report, October 1982-March 1983

    SciTech Connect

    Chikalla, T.D.; Powell, J.A.

    1983-06-01

    This document is one of a series of technical progress reports designed to report radioactive waste management programs at the Pacific Northwest Laboratory. Accomplishments in the following programs are reported: waste stabilization; Materials Characterization Center; waste isolation; low-level waste management; remedial action; and supporting studies.

  4. Annual report on the development and characterization of solidified forms for nuclear wastes, 1979

    SciTech Connect

    Chick, L.A.; McVay, G.L.; Mellinger, G.B.; Roberts, F.P.

    1980-12-01

    Development and characterization of solidified nuclear waste forms is a major continuing effort at Pacific Northwest Laboratory. Contributions from seven programs directed at understanding chemical composition, process conditions, and long-term behaviors of various nuclear waste forms are included in this report. The major findings of the report are included in extended figure captions that can be read as brief technical summaries of the research, with additional information included in a traditional narrative format. Waste form development proceeded on crystalline and glass materials for high-level and transuranic (TRU) wastes. Leaching studies emphasized new areas of research aimed at more basic understanding of waste form/aqueous solution interactions. Phase behavior and thermal effects research included studies on crystal phases in defense and TRU waste glasses and on liquid-liquid phase separation in borosilicate waste glasses. Radiation damage effects in crystals and glasses from alpha decay and from transmutation are reported.

  5. U.S. program assessing nuclear waste disposal in space - A 1981 status report

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Edgecombe, D. S.; Best, R. E.; Compton, P. R.

    1982-01-01

    Concepts, current studies, and technology and equipment requirements for using the STS for space disposal of selected nuclear wastes as a complement to geological storage are reviewed. An orbital transfer vehicle carried by the Shuttle would kick the waste cannister into a 0.85 AU heliocentric orbit. One flight per week is regarded as sufficient to dispose of all high level wastes chemically separated from reactor fuel rods from 200 GWe nuclear power capacity. Studies are proceeding for candidate wastes, the STS system suited to each waste, and the risk/benefits of a space disposal system. Risk assessments are being extended to total waste disposal risks for various disposal programs with and without a space segment, and including side waste streams produced as a result of separating substances for launch.

  6. U.S. program assessing nuclear waste disposal in space - A 1981 status report

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Edgecombe, D. S.; Best, R. E.; Compton, P. R.

    1982-01-01

    Concepts, current studies, and technology and equipment requirements for using the STS for space disposal of selected nuclear wastes as a complement to geological storage are reviewed. An orbital transfer vehicle carried by the Shuttle would kick the waste cannister into a 0.85 AU heliocentric orbit. One flight per week is regarded as sufficient to dispose of all high level wastes chemically separated from reactor fuel rods from 200 GWe nuclear power capacity. Studies are proceeding for candidate wastes, the STS system suited to each waste, and the risk/benefits of a space disposal system. Risk assessments are being extended to total waste disposal risks for various disposal programs with and without a space segment, and including side waste streams produced as a result of separating substances for launch.

  7. Nuclear waste management. Quarterly progress report, July-September 1980

    SciTech Connect

    Chikalla, T.D.

    1980-11-01

    Research is reported on: high-level waste immobilization, alternative waste forms, TRU waste immobilization and decontamination, krypton solidification, thermal outgassing, /sup 129/I fixation, unsaturated zone transport, well-logging instrumentation, waste management system and safety studies, effectiveness of geologic isolation systems, waste/rock interactions, engineered barriers, backfill material, spent fuel storage (criticality), barrier sealing and liners for U mill tailings, and revegetation of inactive U tailings sites. (DLC)

  8. Microbiology in nuclear waste disposal: interfaces and reaction fronts.

    PubMed

    McKinley, I G; Hagenlocher, I; Alexander, W R; Schwyn, B

    1997-07-01

    It is now generally acknowledged that microbial populations will be present within nuclear waste repositories and that the consequences of such activity on repository performance must be assessed. Various modelling approaches--based either on mass balance/thermodynamics or on kinetics--have been developed to provide scoping estimates of the possible development of these populations. Past work has focused on particular areas of the repository which can be considered relatively homogeneous and hence can be represented by some kind of 'box' or 'mixing tank'. In reality, however, waste repositories include a range of engineering materials (steel, concrete, etc.) which are emplaced at depth in a rock formation. Strong chemical gradients--of the type which may be exploited by lithoautotrophic microbial populations--are likely to be found at the contacts between different materials and at the interface between the engineered structures and the host rock. Over the long timescales considered, solute transport processes will cause the locations of strong chemical gradients to move, forming reaction fronts. The high-pH plume resulting from the leaching of cement/concrete in some repository types is a particularly important example of such a reaction front. Redox fronts, which may occur in different areas of all kinds of repositories, also play an important role and would be locations where microbial activity is likely to be significant. In this paper, the key microbial processes expected at (or around) interfaces and fronts will be discussed, with particular emphasis on the development of quantitative models. The applicability of the models used wil be tested by considering similar fronts which can be found in natural systems.

  9. FURTHER DEVELOPMENT OF MODIFIED MONOSODIUM TITANATE, AN IMPROVED SORBENT FOR PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Taylor-Pashow, K.; Hobbs, D.; Fondeur, F.; Fink, S.

    2011-01-12

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include caustic side solvent extraction, for Cs-137 removal, and sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239, and Pu-240. This paper describes recent results from the development of an improved titanate material that exhibits increased removal kinetics and effective capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.

  10. The effect of salinity on waste activated sludge alkaline fermentation and kinetic analysis.

    PubMed

    Jin, Baodan; Wang, Shuying; Xing, Liqun; Li, Baikun; Peng, Yongzhen

    2016-05-01

    The effect of salinity on sludge alkaline fermentation at low temperature (20°C) was investigated, and a kinetic analysis was performed. Different doses of sodium chloride (NaCl, 0-25g/L) were added into the fermentation system. The batch-mode results showed that the soluble chemical oxygen demand (SCOD) increased with salinity. The hydrolysate (soluble protein, polysaccharide) and the acidification products (short chain fatty acids (SCFAs), NH4(+)-N, and PO4(3-)-P) increased with salinity initially, but slightly declined respectively at higher level salinity (20g/L or 20-25g/L). However, the hydrolytic acidification performance increased in the presence of salt compared to that without salt. Furthermore, the results of Haldane inhibition kinetics analysis showed that the salt enhanced the hydrolysis rate of particulate organic matter from sludge particulate and the specific utilization of hydrolysate, and decreased the specific utilization of SCFAs. Pearson correlation coefficient analysis indicated that the importance of polysaccharide on the accumulation of SCFAs was reduced with salt addition, but the importance of protein and NH4(+)-N on SCFA accumulation was increased.

  11. Conversion of corn stover alkaline pre-treatment waste streams into biodiesel via Rhodococci

    SciTech Connect

    Le, Rosemary K.; Wells Jr., Tyrone; Das, Parthapratim; Meng, Xianzhi; Stoklosa, Ryan J.; Bhalla, Aditya; Hodge, David B.; Yuan, Joshua S.; Ragauskas, Arthur J.

    2017-01-01

    The bioconversion of second-generation cellulosic ethanol waste streams into biodiesel via oleaginous bacteria is a novel optimization strategy for biorefineries with substantial potential for rapid development. In this study, one- and two-stage alkali/alkali-peroxide pretreatment waste streams of corn stover were separately implemented as feedstocks in 96 h batch reactor fermentations with wild-type Rhodococcus opacus PD 630, R. opacus DSM 1069, and R. jostii DSM 44719T. Here we show using 31P-NMR, HPAEC-PAD, and SEC analyses, that the more rigorous and chemically-efficient two-stage chemical pretreatment effluent provided higher concentrations of solubilized glucose and lower molecular weight (~70–300 g mol-1) lignin degradation products thereby enabling improved cellular density, viability, and oleaginicity in each respective strain. The most significant yields were by R. opacus PD 630, which converted 6.2% of organic content with a maximal total lipid production of 1.3 g L-1 and accumulated 42.1% in oils based on cell dry weight after 48 h.

  12. Conversion of corn stover alkaline pre-treatment waste streams into biodiesel via Rhodococci

    DOE PAGES

    Le, Rosemary K.; Wells Jr., Tyrone; Das, Parthapratim; ...

    2017-01-13

    We present the bioconversion of second-generation cellulosic ethanol waste streams into biodiesel via oleaginous bacteria is a novel optimization strategy for biorefineries with substantial potential for rapid development. In this study, one- and two-stage alkali/alkali-peroxide pretreatment waste streams of corn stover were separately implemented as feedstocks in 96 h batch reactor fermentations with wild-type Rhodococcus opacus PD 630, R. opacus DSM 1069, and R. jostii DSM 44719T . Here we show using 31P-NMR, HPAECPAD, and SEC analyses, that the more rigorous and chemically-efficient two-stage chemical pretreatment effluent provided higher concentrations of solubilized glucose and lower molecular weight (70 300 gmore » mol1 ) lignin degradation products thereby enabling improved cellular density, viability, and oleaginicity in each respective strain. The most significant yields were by R. opacus PD 630, which converted 6.2% of organic content with a maximal total lipid production of 1.3 g L1 and accumulated 42.1% in oils based on cell dry weight after 48 h.« less

  13. Conversion of corn stover alkaline pre-treatment waste streams into biodiesel via Rhodococci

    DOE PAGES

    Le, Rosemary K.; Wells Jr., Tyrone; Das, Parthapratim; ...

    2017-01-01

    The bioconversion of second-generation cellulosic ethanol waste streams into biodiesel via oleaginous bacteria is a novel optimization strategy for biorefineries with substantial potential for rapid development. In this study, one- and two-stage alkali/alkali-peroxide pretreatment waste streams of corn stover were separately implemented as feedstocks in 96 h batch reactor fermentations with wild-type Rhodococcus opacus PD 630, R. opacus DSM 1069, and R. jostii DSM 44719T. Here we show using 31P-NMR, HPAEC-PAD, and SEC analyses, that the more rigorous and chemically-efficient two-stage chemical pretreatment effluent provided higher concentrations of solubilized glucose and lower molecular weight (~70–300 g mol-1) lignin degradation productsmore » thereby enabling improved cellular density, viability, and oleaginicity in each respective strain. The most significant yields were by R. opacus PD 630, which converted 6.2% of organic content with a maximal total lipid production of 1.3 g L-1 and accumulated 42.1% in oils based on cell dry weight after 48 h.« less

  14. Proceedings of the symposium on Scientific Basis for Nuclear Waste Management XXX

    SciTech Connect

    Dunn, Darrell; Poinssot, Christophe; Begg, Bruce

    2007-07-01

    Management of nuclear waste remains an important international topic that includes reprocessing of commercial nuclear fuel, waste-form design and development, storage and disposal packaging, the process of repository site selection, system design, and performance assessment. Requirements to manage and dispose of materials from the production of nuclear weapons, and the renewed interest in nuclear power, in particular through the Generation IV Forum and the Advanced Fuel Cycle Initiative, can be expected to increase the need for scientific advances in waste management. A broad range of scientific and engineering disciplines is necessary to provide safe and effective solutions and address complex issues. This volume offers an interdisciplinary perspective on materials-related issues associated with nuclear waste management programs. Invited and contributed papers cover a wide range of topics including studies on: spent fuel; performance assessment and models; waste forms for low- and intermediate-level waste; ceramic and glass waste forms for plutonium and high-level waste; radionuclides; containers and engineered barriers; disposal environments and site characteristics; and partitioning and transmutation.

  15. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    DOEpatents

    Boatner, Lynn A.; Sales, Brian C.

    1989-01-01

    Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

  16. The crucial role of nomothetic and idiographic conceptions of time: interdisciplinary collaboration in nuclear waste management.

    PubMed

    Moser, Corinne; Stauffacher, Michael; Krütli, Pius; Scholz, Roland W

    2012-01-01

    The disposal of nuclear waste involves extensive time scales. Technical experts consider up to 1 million years for the disposal of spent fuel and high-level waste in their safety assessment. Yet nuclear waste is not only a technical but also a so-called sociotechnical problem and, therefore, requires interdisciplinary collaboration between technical, natural, social sciences, and the humanities in its management. Given that these disciplines differ in their language, epistemics, and interests, such collaboration might be problematic. Based on evidence from cognitive psychology, we suggest that, in particular, a concept like time is presumably critical and can be understood differently. This study explores how different scientific disciplines understand extensive time scales in general and then focuses on nuclear waste. Eighteen qualitative exploratory interviews were conducted with experts for time-related phenomena of different disciplines, among them experts working in nuclear waste management. Analyses revealed two distinct conceptions of time corresponding to idiographic and nomothetic research approaches: scientists from the humanities and social sciences tend to have a more open, undetermined conception of time, whereas natural scientists tend to focus on a more determined conception that includes some undetermined aspects. Our analyses lead to reflections on potential difficulties for interdisciplinary teams in nuclear waste management. We focus on the understanding of the safety assessment, on potential implications for communication between experts from different disciplines (e.g., between experts from the humanities and engineering for risk assessment and risk communication), and we reflect on the roles of different disciplines in nuclear waste management.

  17. Integrated data base report - 1994: US spent nuclear fuel and radioactive waste inventories, projections, and characteristics

    SciTech Connect

    1995-09-01

    The Integrated Data Base Program has compiled historic data on inventories and characteristics of both commercial and U.S. Department of Energy (DOE) spent nuclear fuel and commercial and U.S. government-owned radioactive wastes. Except for transuranic wastes, inventories of these materials are reported as of December 31, 1994. Transuranic waste inventories are reported as of December 31, 1993. All spent nuclear fuel and radioactive waste data reported are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest DOE/Energy Information Administration (EIA) projections of U.S. commercial nuclear power growth and the expected DOE-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, DOE Environmental Restoration Program contaminated environmental media, commercial reactor and fuel-cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the calendar-year 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions.

  18. Improved volatile fatty acids anaerobic production from waste activated sludge by pH regulation: Alkaline or neutral pH?

    PubMed

    Ma, Huijun; Chen, Xingchun; Liu, He; Liu, Hongbo; Fu, Bo

    2016-02-01

    In this study, the anaerobic fermentation was carried out for volatile fatty acids (VFAs) production at different pH (between 7.0 and 10.0) conditions with untreated sludge and heat-alkaline pretreated waste activated sludge. In the fermentation with untreated sludge, the extent of hydrolysis of organic matters and extent of acidification at alkaline pH are 54.37% and 30.37%, respectively, resulting in the highest VFAs yield at 235.46mg COD/gVS of three pH conditions. In the fermentation with heat-alkaline pretreated sludge, the acidification rate and VFAs yield at neutral pH are 30.98% and 240.14mg COD/gVS, respectively, which are higher than that at other pH conditions. With the glucose or bovine serum albumin as substrate for VFAs production, the neutral pH showed a higher VFAs concentration than the alkaline pH condition. The results of terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that the alkaline pH caused low microbial richness. Based on the results in this study, we demonstrated that the alkaline pH is favor of hydrolysis of organic matter in sludge while neutral pH improved the acidogenesis for the VFAs production from sludge. Our finding is obvious different to the previous research and helpful for the understanding of how heat-alkaline pretreatment and alkaline fermentation influence the VFAs production, and beneficial to the development of VFAs production process.

  19. Nuclear wastes in the arctic: An analysis of arctic and other regional impacts from Soviet nuclear contamination

    SciTech Connect

    1995-09-01

    One of the lasting legacies of the Cold War, and the buildup in nuclear weaponry and military over the past 50 years, is nuclear waste and its threat to human health and the environment. Notable examples of waste dumped into the open environment have caused people and nations to demand information about what was done and what health risks may result. In 1993, disclosures about Russian dumping of submarine reactors, nuclear fuel, and other wastes into the Arctic and North Pacific Oceans brought this region and its problems into the world spotlight. This report examines the environmental and human health impacts from wastes dumped into the Arctic and North Pacific regions, from nuclear contaminants discharged into these environments, and from radioactive releases from both past and future nuclear activities in the region. The report presents what is known and unknown about this waste and contamination and how it may affect public health. It also stresses the need for a stable and enduring institutional framework and international cooperation for long-term observation and monitoring.

  20. Strategic Minimization of High Level Waste from Pyroprocessing of Spent Nuclear Fuel

    SciTech Connect

    Simpson, Michael F.; Benedict, Robert W.

    2007-09-01

    The pyroprocessing of spent nuclear fuel results in two high-level waste streams--ceramic and metal waste. Ceramic waste contains active metal fission product-loaded salt from the electrorefining, while the metal waste contains cladding hulls and undissolved noble metals. While pyroprocessing was successfully demonstrated for treatment of spent fuel from Experimental Breeder Reactor-II in 1999, it was done so without a specific objective to minimize high-level waste generation. The ceramic waste process uses “throw-away” technology that is not optimized with respect to volume of waste generated. In looking past treatment of EBR-II fuel, it is critical to minimize waste generation for technology developed under the Global Nuclear Energy Partnership (GNEP). While the metal waste cannot be readily reduced, there are viable routes towards minimizing the ceramic waste. Fission products that generate high amounts of heat, such as Cs and Sr, can be separated from other active metal fission products and placed into short-term, shallow disposal. The remaining active metal fission products can be concentrated into the ceramic waste form using an ion exchange process. It has been estimated that ion exchange can reduce ceramic high-level waste quantities by as much as a factor of 3 relative to throw-away technology.