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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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Laser Cladding Modeling and Operation Applied to Plasma Facing Components (Final Report)
This report summarizes progress during the performance period of June 17, 2011 to March 17, 2012 for DOE Award number DE-SC0006270. Modeling of the LENS process to construct tungsten on both copper and Inconel substrates was performed and experimentally tested with good results. During the course of the Phase I effort Nanohmics, working collaboratively with Purdue University, modeled and experimentally confirmed that the Laser-Engineered Net Shaping (LENS) process can successfully clad tungsten to both Inconel and copper substrates. Early in Phase I, work was carried out using the LENS process on Inconel substrates that were previously clad to steel. In this regard, nine tungsten tracks were cladded onto an Inconel 625 substrate. The substrate consisted of several layers of Inconel 625 cladded onto a bar of steel 25.4 mm thick and 50.8 mm wide. The Inconel portion of the bar was then cut flat on a mill so that the layer was 2.2 mm thick. The powder was applied to the Inconel 625 surface using both pre-placed powder and blown powder techniques and the powder was melted onto the Inconel surface with varying laser powers and laser travel speeds. The laser used in these experiments is a 4000 W Nuvonyx diode laser (wavelength 808 nm) with a line beam profile 12 mm long and 0.5 mm wide. The laser travel direction was always perpendicular to the long direction of the beam so as to create a 12 mm wide clad track.
GrayQb TM Single-Faced Version 2 (SF2) Open Environment Test Report (Rev. 1)
This report details the design upgrades incorporated into the new version of the GrayQb TM SF2 device and the characterization testing of this upgraded device. Results from controlled characterization testing in the Savannah River National Laboratory (SRNL) R&D Engineering Imaging and Radiation Lab (IRL) and the Savannah River Site (SRS) Health Physics Instrument Calibration Laboratory (HPICL) is presented, as well as results from the open environment field testing performed in the E-Area Low Level Waste Storage Area. Resultant images presented in this report were generated using the SRNL developed Radiation Analyzer (RAzer TM ) software program which overlays the radiation contour images onto the visual image of the location being surveyed.
Plasma Facing Components and Advanced System Design:A technical review of FY14-17 work
Fusion energy holds the promise of being a major source of world energy in this century and beyond. One of the two major approaches to controlled fusion is confinement of hot plasma gas by strong magnetic fields. Many countries have experimental devices, and ITER is a large international collaboration device being built in France with U.S. participation. Because fusion gain of the deuterium/tritium (D/T) plasma fuel increases strongly with temperature, increasing the core-plasma energy confinement time, tE, has been a key requirement. With excellent progress on increasing tE, considerable attention has turned to other requirements for an economical power plant. Because core plasma tE will always be finite, plasma is exhausted from the core and strikes surrounding material surfaces with peak heat fluxes that challenge the structural integrity of present-day materials. Furthermore, sputtering of such material can introduce impurities into the core that radiate energy or dilute the D/T fuel, thereby reducing fusion gain. Simulationbased assessments of such plasma/wall interactions is the goal of the two projects described here.
An Atomistic Introduction to Orientation Relations Between Phases in the Face-centered Cubic to Body-centered Cubic Phase Transition in Iron and Steel
We establish an atomistic view of the high- and low-temperature phases of iron/steel as well as some elements of the phase transition between these phases on cooling. In particular we examine the 4 most common orientation relationships between the high temperature austenite and low-temperature ferrite phases seen in experiment. With a thorough understanding of these relationships we are prepared to set up various atomistic simulations, using techniques such as Density Functional Theory and Molecular Dynamics, to further study the phase transition, in particular, quantities needed for Phase Field Modeling, such as the free energies of bulk phases and the phase transition front propagation velocity.
Local Crystallographic Orientation Correlation Measurements Connecting the Processing and Properties of Face-Centered Cubic Metals
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U.S. Department of Energy Free-Air CO 2 Enrichment Experiments: FACE Results, Lessons, and Legacy
In the 1970s, growing concern about potential long-range consequences of carbon dioxide (CO 2 ) emissions from the combustion of fossil fuels prompted the U.S. Department of Energy (DOE) to begin developing a CO 2 research program. The goal was to obtain the scientific information needed to reduce uncertainty and develop a knowledgebase for decision-making. At its start in 1980, this program had three components: the global carbon cycle, climate effects, and vegetation effects. The vegetation effects component recognized that increased atmospheric CO 2 could be a potential benefit to vegetation and crops because CO 2 is an essential resource for plant growth. In addition to increasing crop yield, program developers and researchers recognized that this fertilizer effect could also result in greater storage of fossil fuel CO 2 by forests. Initial experiments were small in scale and scope and focused on the photosynthesis, physiology, and water use of crop plants, but the focus shifted toward responses of plants in natural systems, as needed for connections to the global carbon cycle. Program research investigated CO 2 interactions with other environmental variables, emphasizing field research whenever possible and recognizing that exposure to elevated CO 2 concentrations under realistic field conditions should lead to better predictions of plant response. Whole-ecosystem field experiments were instituted in low-stature ecosystems, but experiments to address forest responses necessarily relied on tree seedlings or saplings in open-top chambers (OTCs) and not within intact forest ecosystems. The need for larger-scale, longer-duration experiments in each of the world’s six major biomes (tundra, boreal forest, temperate forest, tropical forest, grassland, and desert) became clear, and for these experiments, free-air CO 2 exposure facilities were necessary. This report summarizes the objectives and main results of DOE-sponsored experiments employing such facilities, along with the outcomes from research on ecosystem responses using field chambers (see Fig. ES.1, p. x). Additionally, this report highlights the many successes of DOE CO 2 enrichment studies and considers the lessons learned that can be used to guide future initiatives.
Waves of Data: Modern Challenges Facing the DOE Marine and Hydrokinetic Data Repository (MHKDR) and the Marine Energy Industry.
Abstract not provided.
Surface structure characterization of plasma facing materials with impact-collision ion scattering spectroscopy.
Abstract not provided.
Application of Particle Accelerators to Mitigate Energy and Climate Change Problems Facing America
Reliable CO 2 -free baseload power is needed to address ever-increasing demands for electricity while minimizing adverse climate change. Diversified power supply provided by solar, wind, geothermal, and nuclear reactors can displace the use of fossil fuels. The United States (U.S.) is taking a new look at nuclear power as a source of electrical energy and the nuclear industry is proposing new approaches which may minimize capital costs. However, nuclear power comes with a variety of technical problems. Chief among those is managing the used fuel from nuclear reactors. No long-term, practicable solution to this problem is available. The lack of progress on a comprehensive waste management strategy restricts growth in the nuclear power industry and minimizes the role that nuclear energy may serve as part of a zero-carbon future (Bahr, 2021). According to the Nuclear Waste Policy Act of 1982, as amended, the U.S. Government has possession of the used reactor fuel and incurs large annual storage fees paid to utilities to store and safeguard the accumulated used fuel. In effect, short term on-site storage of nuclear waste is the current waste management plan. The amount of used reactor fuel in the U.S. is approximately 80,000 metric tons. While no geologic repository exists within the U.S., the potential site at Yucca Mountain, NV would accommodate 70,000 metric tons, which fails to meet current and future needs. Given the technical and political challenges associated with establishing a single geological storage site, it is necessary for the U.S. to implement technologies that improve the suitability of geological storage by reducing the volume and radiotoxicity of stored material. No extant technology meets this need. Accelerator driven waste burners have been proposed as a scalable method to process used nuclear fuel, however considerable technical challenges remain which impede commercialization. Innovations in design require investigation of novel materials, development of accurate models and simulations, and a comprehensive assessment of safety and performance. This proposal elaborates how LANL is uniquely positioned to make key contributions to this area of research.
Furthering Advancement to Address Tough Problems Facing the Solar Energy Industry, Spurring the Next Wave of Solar Technology Innovations through Three Progressive Challenges and Cash Incentives (Final Report)
The American-Made Solar Prize is a prize competition from the U.S. Department of Energy that is designed to revitalize U.S. solar manufacturing. The competition aims to support the growth of U.S. solar manufacturing and reenergize American energy innovation by tapping into American's competitive spirit and the nation's unparalleled innovation ecosystem leveraging national labs, incubators, facilities and more. National Renewable Energy Lab (NREL) will provide technical and business advisement to the noted Solar Prize finalists. The CRADA Participant is in the process of developing a new continuous process for making silicon wafers for solar cells in a novel approach to horizontal ribbon growth. Under this CRADA, NREL will characterize the chemical, electrical, and crystallographic properties of the as-produced wafers to and work with the CRADA Participant to improve and modify processing conditions.
Crush Gun Impact of Unconfined Explosive with Flat-Faced Projectiles at Nominal Velocity of 60 m/s
A pneumatic gun apparatus was designed and built to deliver crushing impacts at velocities of 0-70 m/s. The apparatus is designed to halt the projectile (if desired) approximately 1 mm before impacting the sapphire imaging surface, preventing a complete “pinch” condition from attaining. The primary diagnostics include high-speed visible videography and infrared imaging to determine spatial temperature rise of the sample during impact.
ZrH 2 and ZrH 2-x Crystal Structures: Face-Centered Cubic (FCC) to Body-Centered Tetragonal (BCT) “Teufer” Unit Cell Transformation [Slides]
Abstract not provided.
Machine learning assisted prediction of tungsten heavy alloy plasma facing component performance for fusion energy applications
Tungsten and tungsten heavy alloys (WHAs), known for their remarkably high hardness, durability, and corrosion resistance, play a critical role in the thriving development of nuclear fusion reactors in recent years. However, the exploration in tungsten alloys for the nuclear-related applications has been limited by the difficulty of manufacturing and the complexity of experiments to reproduce the environment of nuclear reaction. Therefore, this project aims to utilize nanoscale simulation methods such as density functional theory (DFT) and molecular dynamics (MD) with the help of machine learning techniques to not only understand the mechanisms of tungsten alloys but also allow us to computationally predict their mechanical behaviors under extreme environments. One critical problem of the application of WHAs in nuclear reactors is the surface melting. In the current design of the SPARC reactor, the WHA, W97Ni2.1Fe0.9 or W97NiFe, is chosen to be the first wall components to confine the plasma where the particles are fiercely moving and colliding into each other to create nuclear fusion reaction. This process will generate extremely high heat flux onto these WHA tiles, leaving high surface temperature that could possibly melt the surface of the WHA tiles, As illustrated in Fig. 1(a). a laser experiment previously done illustrates that a rough surface damage would be made after the surface melting where the matrix area mainly composed of nickel and iron as shown in Fig. 1(b), will first melt and then leave vacancies between these tungsten grains. Unfortunately, these kinds of roughness on the first-wall components could be deadly to the plasma inside a Tokmak reactor because the heat that is supposed to dissipate at a designed ratio through the tiles may in turn be excessively absorbed and accumulated on any uneven area of the surface, which will eventually make the whole nuclear reaction fail. In this project, we will introduce a machine learning potential, Allegro, based on DFT calculation and then build a MD model for W-Ni-Fe alloys.
Large-scale Quantum-accurate Atomistic Simulation of Plasma-facing Materials for Fusion Energy
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A User-Facing Metric to Quantify the Quality of Mobility (CRADA Final Report)
The leading urban mobility data analytics firm StreetLight Data, Inc. partnered with the National Renewable Energy Laboratory to explore a commercial version of the Mobility Energy Productivity (MEP) metric. The commercialization effort was aimed to expand the adoption of the metric to key stakeholders in the urban planning space. Research comprised industry analysis, stakeholder feedback and conducting transportation practitioner focus groups. StreetLight concluded that commercialization of MEP is not feasible in the current market because users need a dynamic MEP tool that enables scenario planning. It should be able to calculate a MEP score dynamically (near instantaneous) when different inputs are changed.