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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Crystallization Constraints for WTP LAW Operations: Assessment of CCC Impacts on VHT and PCT

Much work has been done to expand the glass composition region available for operation of the Hanford Waste Treatment and Immobilization Plant. This includes the development of updated glass property-composition models as well as constraints. This report supports this effort by suggesting constraints for avoiding excessive, and likely detrimental, crystallization during slow cooling of the low-activity glass waste forms in their containers. The constraints target crystals in the Na-Al-silicate and Na-Ca-silicate families. These types of crystals were found to be potentially detrimental to glass durability as they remove Al and Si from the glass matrix, resulting in poor performance of the residual glass during testing such as the Product Consistency Test and the Vapor Hydration Test. Using previously acquired results and results from testing during this effort, the constraints described in the report were determined, and are suggested as options to reduce the risk of forming crystals of the types and concentrations that are likely detrimental to glass durability.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Glass Compositions and Properties of Enhanced Waste Glass with High Alumina Content for High-Level Waste

This report documents the work performed to collect critical property data on high-level waste (HLW) glasses with high alumina content. This report covers the experimental results of thermal, physical, chemical, and electrical properties of 46 high alumina (15 to 30 wt%) borosilicate waste-glass compositions with one duplicate for a total of 47 glasses. These experimental results are essential for developing property-composition models for the future operation of the Waste Treatment and Immobilization Plant (WTP) currently under construction at the Hanford Site in Richland, Washington. Pacific Northwest National Laboratory (PNNL) was requested by the U.S. Department of Energy’s Office of River Protection to provide expert evaluation and experimental work in support of the vitrification technology development program.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Glass Crystallization Constraints for WTP LAW Operations: Assessment of Isothermal Treatments on Crystal Formation

Much work has been done to expand the glass composition region available for operation of the Hanford Waste Treatment and Immobilization Plant. This includes the development of updated glass property-composition models as well as constraints. This report supports this effort by suggesting constraints for avoiding excessive, and likely detrimental, crystallization during melter operation while processing advanced low-activity glass waste forms. The constraints target SnO 2 and ZrO 2 crystals that can form when melter temperatures drop below 1100 °C. These types of crystals were found to be potentially detrimental during processing as they are denser than low-activity waste glass melts. SnO 2 , density of 6.95 g/cm3, and ZrO 2 , density of 5.68 g/cm3, have the potential to form during melter idling and settle to the bottom of the less dense glass melt (approximate density 2.65 g/cm3). If the crystals are present in appreciable amounts, they can result in blockages of the pour-spout riser, which impacts glass pouring and melter operation. Using previously acquired results and results from testing during this effort, constraints were determined and are suggested as options to reduce the risk of forming crystals of the types and concentrations that are likely detrimental to melter operation.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Glass Crystallization Constraints for WTP LAW Operations: Assessment of Isothermal Treatments on Crystal Formation

Much work has been done to expand the glass composition region available for operation of the Hanford Tank Waste Treatment and Immobilization Plant. This includes the development of updated glass property-composition models as well as constraints. This report supports this effort by suggesting constraints for avoiding excessive, and likely detrimental, crystallization during melter operation while processing advanced low-activity glasses. The constraints target Cassiterite and ZrO 2 -containing phases (ZCP, e.g., Baddeleyite and Zircon) that can form when melter temperatures drop below 1100 °C. These types of crystals were found to be potentially detrimental during processing as they are denser than low-activity waste glass melts; with densities of 6.95 g/cm 3 for Cassiterite and 5.68 g/cm 3 for Baddeleyite (the most prevalent ZCP). Compared to melt densities of approximately 2.65 g/cm 3 . Thus, they have the potential to form during melter idling and settle to the bottom of the melter or inside the melter. If the crystals are present in appreciable amounts, they can result in blockages of the pour-spout riser, which impacts glass pouring and melter operation. Additionally, SnO 2 and ZrO 2 are added to glass formulations to improve glass durability. Their precipitation from the melt may reduce overall glass durability. Using previously acquired results and results from testing during this effort, the following constraints (Table S.1) were determined and are recommended to reduce the risk of forming crystals of the types and concentrations that are likely detrimental to melter operation.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Melter Tests to Define LAW Halide, Chromium and Phosphate Concentrations, VSL-14R3070-1 (February 2014)

The Office of River Protection is examining options to optimize the Low Activity Waste (LAW) Facility and LAW glass waste form. One option under evaluation is to enhance the waste processing rate of the vitrification plant currently under construction. It is likely that the capacity of the LAW vitrification plant can be increased incrementally by implementation of a variety of low-risk, high-probability changes, either separately or in combination. The present work addressed the potential formation of secondary sulfate phases while processing high waste loading LAW formulations with elevated halide, chromium, and phosphate feed concentrations over a wide range of LAW waste types, including those with high potassium concentrations. The present work will be followed by a second phase of testing, described in a separate Test Plan, the results of which will be reported elsewhere. The combined results from these tests will be used as inputs to develop concentration limits for these components in the LAW glass property-composition models and to support the modification and updating of the current WTP LAW glass formulation algorithm.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Characterization and High Temperature Electrical Properties of Brazed Joints of La0.8Sr0.2CrO3 with Nickel and Nickel Alloys

This study investigates the high-temperature electrical properties and microstructural characteristics of brazed joints combining La₀.₈Sr₀.₂CrO₃ (LSC) with nickel and nickel-based alloys. Using nickel-based filler metals (NB LM and NB 130), the joints were tested in controlled atmospheres (95% N₂ and 5% H₂). Electrical resistivity was analyzed across a range of temperatures (25–727°C), and contact resistance was evaluated using a composite model. Results indicate that joint resistance decreases with increasing temperature, with optimal brazing achieved at 1160°C. Diffusion processes involving Si, Ni, O, and Sr were identified, with silicon oxide formation contributing to joint bonding.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2026

Melter Tests to Define LAW Halide Concentrations, Phase 2

The present work represents the second of two phases to address the formation of secondary sulfate phases while processing high waste loading LAW formulations with elevated halide, chromium, and phosphate feed concentrations over a wide range of LAW waste types, including those with high potassium concentrations. The Test Plan for the present work outlines a series of tests designed to assess the formation of secondary phases over a range of sulfur and halide concentrations for two LAW streams and associated glass formulations as well as crucible testing to identify additives that have the potential to suppress the formation of secondary phases for wastes with high chlorine contents. The combined results from both phases of testing and from previous tests with these LAW waste streams will be used as inputs to future work to develop concentration limits for these components in the LAW glass property composition models and to support the modification and updating of the current WTP LAW glass formulation algorithm.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

HLW Processing for Complementary Disposition Strategy: Development and Testing of Glass and Feed Formulations

The objective of the work described herein was to develop and identify HLW glass compositions and glass forming additive blends for vitrification of selected HLW streams, which have undergone various degrees of washing but no other pretreatment, while maintaining high WLs, high processing rates, and acceptable glass properties. The glass formulations were actively designed and based on previous formulation experience and testing at VSL. The WTP baseline HLW property-composition models were used to select glass formulations for testing and to predict various glass properties. Crucible-scale fabrication of the HLW glasses that were formulated was performed and the product glasses were characterized with respect to select properties. A total of 10 HLW glasses were developed and tested for five fully washed waste batches and one singly washed waste batch.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Hadronization of quarks and correlated di-hadron production in hard scattering

Understanding the dynamics of partons in general, and non perturbative sea, in particular, will be crucial for the understanding of strong interactions. Correlations of the spin of the target or/and the momentum and the spin of quarks, combined with final state interactions define the azimuthal distributions of produced particles. Production of correlated hadron pairs, in addition, will play an increasingly important role in the interpretation of pion electroproduction data in general, and hadronization process of quarks, in particular. More significant, than originaly anticipated, fraction of pions coming from correlated di-hadrons, indicated by recent CLAS12 measurements, and supported by various realistic models describing the hadronization process, may have a significant impact on various aspects of data analysis, including the modeling, composition, and interpretation of semi-inclusive DIS data, as well as calculations of radiative corrections. Studies of the nucleon structure beyond the traditional leading twist and current fragmentation of inclusive hadrons, provide qualitatively new tools to study the nucleon structure and extension of large x region well covered by JLab, to large Q2 at the EIC where it will be very important in interpretation of the data from JLab.

Avakian, Harut↗
DOE OSTI2018

Molecular Models and Wave Function Definitions for Models A-G of the [2Fe]F Cluster in FeFe-hydrogenase Maturase Enzyme HydF

The dataset contains all relevant atomic positional coordinates for 2Fe-cluster models, and electronic wave function data (using formatted Gaussian checkpoint files) as described in the related publication (see citation below). The version 2.0 contains additional models for [2Fe-2S] cluster linked [2Fe]F constructs. The top folder contains "analysis.xlsx" electronic spreadsheet that summarizes all the numerical results for absolute and relative electronic energy values, internal coordinates, calculated and scaled vibrational frequencies for diatomic stretching modes. The details of developing scaled quantum forcefields as a function of level of theory and model composition are also given. The schematic structural definitions are given in the "models.pdf" file and keys for abbreviations are provided in "symbols.txt" file.

carbonyl stretching frequencies↗
NASA NTRS1968

Geochemistry of andesites.

Trace element geochemistry of calc-alkaline andesites, discussing crustal composition models and trace elements distribution

Taylor, S. R.↗
NASA NTRS1973

Iron abundance in the moon from magnetometer measurements

Apollo 12 and 15 lunar surface magnetometer data with simultaneous lunar orbiting Explorer 35 data are used to plot hysteresis curves for the whole moon. From these curves a whole-moon permeability mu = 1.029 + 0.024 or - 0.019 is calculated. This result implies that the moon is not composed entirely of paramagnetic material, but that ferromagnetic material such as free iron exists in sufficient amounts to dominate the bulk lunar susceptibility. From the magnetic data the ferromagnetic free iron abundance is calculated. Then for assumed compositional models of the moon the additional paramagnetic iron is determined, yielding total lunar iron content. The calculated abundances are as follows: ferromagnetic free iron = 5 + or - 4 wt. percent, and total iron in the moon = 9 + or - 4 wt. percent.

Parkin, C. W.↗
NASA NTRS1972

Thermal expansion compatibility of ceramic chip capacitors mounted on alumina substrates.

The thermal expansion coefficients of a representative sample of BaTiO3 and TiO2 ceramic chip capacitors and alumina substrates have been examined. These data have revealed large potential mechanical stresses under thermal cycling. A mathematical analysis of a composite model of the capacitor to predict the thermal expansion and modulus of elasticity and an analysis of the capacitor-substrate system to predict the magnitude of thermally induced stresses have been conducted. In all cases studied, thermally induced stresses great enough to cause capacitor body rupture or termination failure was predicted.

Allen, R. V.↗