Integrated Testing of the Srl-165 Glass Waste Form

1986 ◽  
Vol 84 ◽  
Author(s):  
D.L. Phinney ◽  
F.J. Ryerson ◽  
V.M. Oversby ◽  
W.A. Lanford ◽  
R.D. Aines ◽  
...  
Keyword(s):  
Mass Balance ◽  
High Surface ◽  
High Energy ◽  
Leach Solution ◽  
Solution Chemistry ◽  
Waste Form ◽  
Depth Of Penetration ◽  
Glass Waste ◽  
Integrated Testing ◽  
Radionuclide Release

AbstractIntegrated testing of the important components of a glass waste form waste package has been performed in order to gain a better understanding of the processes of radionuclide release and transport in the near field environment. Based upon an interpretation of the depth of penetration of hydrogen in reacted SRL-165 glass we have modeled the radionuclide release from the glass as a combined process of (1) the diffusive exchange of alkalis and boron in the glass for hydrogen species in the solution (D=10−16 cm2/s) and (2) surface dissolution. Surface dissolution controls the release of components not exchanged by diffusion and takes place at a rate of 1.5-3.0 μm/yr. Subsequent to release the radionuclides may remain in the leach solution, diffuse into the tuff, or precipitate as secondary phases. Precipitation is particularly important for plutonium and americium. Diffusive transport of radionuclides through the tuff takes place at an extremely slow rate, D=10−16 cm2/s. As such, the mass of radionuclides incorporated in the tuff by diffusion during the tests is inconsequential relative to that in the leach solution (with the exception of plutonium) and can be ignored in mass balance calculations. Mass balance calculations based upon the release of radionuclides by surface dissolution of the glass waste form are in good agreement with observed solution chemistry when allowances are made for a pulse of dissolution early in the tests. This pulse may be due to either the rapid dissolution of high-energy surface features early in the inLegrated tests, or an initially high surface dissolution rate that decreases with time as silica saturation is approached [1], or a combination of the two.

scholarly journals Integrated testing of the SRL-165 glass waste form

10.2172/60000 ◽  
1986 ◽  
Author(s):  
D.L. Phinney ◽  
F.J. Ryerson ◽  
V.M. Oversby ◽  
W.A. Lanford ◽  
R.D. Aines ◽  
...  
Keyword(s):  
Waste Form ◽  
Glass Waste ◽  
Integrated Testing

scholarly journals Low-Roughness-Surface Additive Manufacturing of Metal-Wire Feeding with Small Power

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4265
Author(s):  
Bobo Li ◽  
Bowen Wang ◽  
Greg Zhu ◽  
Lijuan Zhang ◽  
Bingheng Lu
Keyword(s):  
Additive Manufacturing ◽  
High Surface ◽  
Deposition Process ◽  
High Energy ◽  
Width Ratio ◽  
Thin Wall ◽  
Small Power ◽  
High Surface Quality ◽  
Wall Structures ◽  
Wire Feed

Aiming at handling the contradiction between power constraint of on-orbit manufacturing and the high energy input requirement of metal additive manufacturing (AM), this paper presents an AM process based on small-power metal fine wire feed, which produces thin-wall structures of height-to-width ratio up to 40 with core-forming power only about 50 W. In this process, thermal resistance was introduced to optimize the gradient parameters which greatly reduces the step effect of the typical AM process, succeeded in the surface roughness (Ra) less than 5 μm, comparable with that obtained by selective laser melting (SLM). After a 10 min electrolyte-plasma process, the roughness of the fabricated specimen was further reduced to 0.4 μm, without defects such as pores and cracks observed. The ultimate tensile strength of the specimens measured about 500 MPa, the relative density was 99.37, and the Vickers hardness was homogeneous. The results show that the proposed laser-Joule wire feed-direct metal deposition process (LJWF-DMD) is a very attractive solution for metal AM of high surface quality parts, particularly suitable for rapid prototyping for on-orbit AM in space.

The Leaching Behavior of a Glass Waste Form – Part I: The Characteristics of Surface Layers

1984 ◽  
Vol 67 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Takashi Murakami ◽  
Tsunetaka Banba
Keyword(s):  
Waste Form ◽  
Surface Layers ◽  
Leaching Behavior ◽  
Glass Waste ◽  
Form Part

scholarly journals Liquid Phase Synthesis of CoP Nanoparticles with High Electrical Conductivity for Advanced Energy Storage

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Guo-Qun Zhang ◽  
Bo Li ◽  
Mao-Cheng Liu ◽  
Shang-Ke Yuan ◽  
Leng-Yuan Niu
Keyword(s):  
Electrical Conductivity ◽  
Energy Storage ◽  
Liquid Phase ◽  
Specific Capacitance ◽  
Current Density ◽  
High Surface ◽  
High Surface Area ◽  
High Energy ◽  
High Energy Density ◽  
Energy Storage Materials

Transition metal phosphide alloys possess the metalloid characteristics and superior electrical conductivity and are a kind of high electrical conductive pseudocapacitive materials. Herein, high electrical conductive cobalt phosphide alloys are fabricated through a liquid phase process and a nanoparticles structure with high surface area is obtained. The highest specific capacitance of 286 F g−1 is reached at a current density of 0.5 A g−1. 63.4% of the specific capacitance is retained when the current density increased 16 times and 98.5% of the specific capacitance is maintained after 5000 cycles. The AC//CoP asymmetric supercapacitor also shows a high energy density (21.3 Wh kg−1) and excellent stability (97.8% of the specific capacitance is retained after 5000 cycles). The study provides a new strategy for the construction of high-performance energy storage materials by enhancing their intrinsic electrical conductivity.

Validation of a Nuclear Waste Repository Performance Assessment Model:Comparison of Theory With Experiment

1987 ◽  
Vol 112 ◽  
Author(s):  
R. W. Geldart ◽  
B. P. Mcgrail ◽  
K. C. Rhoads ◽  
M. J. Apted
Keyword(s):  
Mass Transfer ◽  
Dissolution Kinetics ◽  
Waste Form ◽  
Nuclear Waste Repository ◽  
Transfer Model ◽  
Mass Transfer Model ◽  
Buffer Solution ◽  
Simulated Waste ◽  
Limited Mass ◽  
Radionuclide Release

AbstractLaboratory tests were conducted to validate a radionuclide mass transfer model. During the experiments, cesium and uranium releases from a simulated waste form embedded in an isotropic medium of quartz sand were measured. A 0.01 M NaH2PO4 buffer solution flowed past the waste form. Downstream concentrations obtained from computer simulations were compared with experimentally measured concentrations of cesium and uranium. Uranium release was found to be controlled by solubility-limited mass transfer, while cesium release was controlled by waste form dissolution kinetics. It was also found that the effects of dissolution on groundwater chemistry must be coupled with solubility-limited mass transfer models to defensibly predict radionuclide release rates under realistic repository conditions.

Diffusion of Plutonium in Compacted, Brine-Saturated Bentonite

1984 ◽  
Vol 44 ◽  
Author(s):  
E. J. Nowak
Keyword(s):  
Radioactive Waste ◽  
Packing Density ◽  
Solution Chemistry ◽  
Lithostatic Pressure ◽  
Release Rates ◽  
Rock Types ◽  
Diffusion Studies ◽  
Engineered Barriers ◽  
Radionuclide Release ◽  
Wyoming Bentonite

AbstractDiffusivities were measured for plutonium in brine-saturated compacted Wyoming bentonite. Complexities of the solution chemistry and retardation of transuranics necessitate diffusion studies under conditions that are specific for repository host rock types in this case salt. Diffusivity values in the range of 10−15 to 10−14 m2/s were obtained for bentonite at a packing density of 1800 kg/m3. That density was obtained by compaction at 15 i0Pa, a typical lithostatic pressure in a repository in salt at 650 m depth. Even a 0.05 m (2 inch) thick bentonite-containing engineered barrier could decrease radionuclide release rates by approximately 4 orders-of-magnitude if the diffusivity for that radionuclide were in the observed range of 10−15 to 10−14 m2/s. These results confirm the effectiveness of uncompacted bentonite-containing materials as engineered barriers for radioactive waste isolation.

scholarly journals Recent Advances in Lithiophilic Porous Framework toward Dendrite-Free Lithium Metal Anode

2020 ◽  
Vol 10 (12) ◽  
pp. 4185 ◽  
Author(s):  
Rajesh Pathak ◽  
Yue Zhou ◽  
Qiquan Qiao
Keyword(s):  
Rational Design ◽  
Safety Concern ◽  
Coulombic Efficiency ◽  
High Surface ◽  
High Energy ◽  
High Energy Density ◽  
Research Progress ◽  
Lithium Metal ◽  
Metal Anode ◽  
Lithium Metal Anode

Rechargeable lithium metal anode (LMA) based batteries have attracted great attention as next-generation high-energy-density storage systems to fuel the extensive practical applications in portable electronics and electric vehicles. However, the formation of unstable solid-electrolyte- interphase (SEI) and growth of lithium dendrite during plating/stripping cycles stimulate safety concern, poor coulombic efficiency (CE), and short lifespan of the lithium metal batteries (LMBs). To address these issues, the rational design of micro/nanostructured Li hosts are widely adopted in LMBs. The high surface area of the interconnected conductive framework can homogenize the Li-ion flux distribution, lower the effective current density, and provides sufficient space for Li accommodation. However, the poor lithiophilicity of the micro/nanostructure host cannot govern the initial lithium nucleation, which leads to the non-uniform/dendritic Li deposition and unstable SEI formation. As a result, the nucleation overpotential and voltage hysteresis increases, which eventually leads to poor battery cycling performance. Thus, it is imperative to decorate a micro/nanostructured Li host with lithiophilic coatings or seeds for serving as a homogeneous nucleation site to guide the uniform lithium deposition. In this review, we summarize research progress on porous metal and non-metal based lithiophilic micro/nanostructured Li hosts. We present the synthesis, structural properties, and the significance of lithiophilic decorated micro/nanostructured Li host in the LMBs. Finally, the perspectives and critical challenges needed to address for the further improvement of LMBs are concluded.

Materials Interactions Relating to Long-Term Geologic Disposal of Nuclear Waste Glass

1986 ◽  
Vol 84 ◽  
Author(s):  
Ned E. Bibler ◽  
Carol M. Jantzen
Keyword(s):  
Nuclear Waste ◽  
Review Paper ◽  
Waste Glass ◽  
Waste Form ◽  
Glass Waste ◽  
Waste Package ◽  
Geologic Disposal ◽  
Nuclear Waste Glass ◽  
Backfill Materials

AbstractIn the geologic disposal of nuclear waste glass, the glass will eventually interact with groundwater in the repository system. Interactions can also occur between the glass and other waste package materials that are present. These include the steel canister that holds the glass, the metal overpack over the canister, backfill materials that may be used, and the repository host rock. This review paper systematizes the additional interactions that materials in the waste package will impose on the borosilicate glass waste form-groundwater interactions. The repository geologies reviewed are tuff, salt, basalt, and granite. The interactions emphasized are those appropriate to conditions expected after repository closure, e.g. oxic vs. anoxic conditions. Whenever possible, the effect of radiation from the waste form on the interactions is examined. The interactions are evaluated based on their effect on the release and speciation of various elements including radionuclides from the glass. It is noted when further tests of repository interactions are needed before long-term predictions can be made.

scholarly journals Facile One-Step Hydrothermal Synthesis of the rGO@Ni3V2O8 Interconnected Hollow Microspheres Composite for Lithium-Ion Batteries

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2389
Author(s):  
Faizan Ghani ◽  
In Wook Nah ◽  
Hyung-Seok Kim ◽  
JongChoo Lim ◽  
Afifa Marium ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Lithium Ion Batteries ◽  
High Surface ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
High Energy ◽  
Hollow Microspheres ◽  
High Energy Density ◽  
Layered Crystal ◽  
One Step

Low-cost, vanadium-based mixed metal oxides mostly have a layered crystal structure with excellent kinetics for lithium-ion batteries, providing high energy density. The existence of multiple oxidation states and the coordination chemistry of vanadium require cost-effective, robust techniques to synthesize the scaling up of their morphology and surface properties. Hydrothermal synthesis is one of the most suitable techniques to achieve pure phase and multiple morphologies under various conditions of temperature and pressure. We attained a simple one-step hydrothermal approach to synthesize the reduced graphene oxide coated Nickel Vanadate (rGO@Ni3V2O8) composite with interconnected hollow microspheres. The self-assembly route produced microspheres, which were interconnected under hydrothermal treatment. Cyclic performance determined the initial discharge/charge capacities of 1209.76/839.85 mAh g−1 at the current density of 200 mA g−1 with a columbic efficiency of 69.42%, which improved to 99.64% after 100 cycles. High electrochemical performance was observed due to high surface area, the porous nature of the interconnected hollow microspheres, and rGO induction. These properties increased the contact area between electrode and electrolyte, the active surface of the electrodes, and enhanced electrolyte penetration, which improved Li-ion diffusivity and electronic conductivity.

Spent Fuel: Characterization Studies and Dissolution Behaviourunder Disposal Conditions

1987 ◽  
Vol 112 ◽  
Author(s):  
L. H. Johnson ◽  
D. W. Shoesmith ◽  
S. Stroes-Gascoyne
Keyword(s):  
Release Kinetics ◽  
Fission Products ◽  
Solution Chemistry ◽  
Future Research ◽  
Spent Fuel ◽  
Research Areas ◽  
Dissolution Model ◽  
Underground Disposal ◽  
Radionuclide Release

AbstractThe concept of disposal of unreprocessed spent fuel has now been under study internationally for over ten years. Considerable progress has been made in understanding the factors that will control radionuclide release from spent fuel in an underground disposal vault. This progress is reviewed and the research areas of significance in providing further data for source term models are discussed. Key areas for future research are identified; these include improved characterization of spent fuel to determine the inventories of fission products at grain boundaries, together with their release kinetics; and a better understanding of the effects of solution chemistry on spent fuel dissolution, in particular the effects of salinity, redox chemistry, and radiolysis of groundwater. Approaches to modelling the dissolution of spent fuel are discussed, and a possible approach for developing an oxidative dissolution model is outlined.

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