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The objectives of this report were to optimize and fabricate full density Inconel 625 samples using direct metal laser fusion, an additive manufacturing process; and to compare and evaluate precipitation and solid solution strengthening of Inconel 625 produced by PBF to conventional processed material.
The Stockpile Stewardship Program (SSP) is an integrated technical program for maintaining the safety, surety, and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational capabilities to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources that support annual stockpile assessment and certification, study advanced nuclear weapons design and manufacturing processes, analyze accident scenarios and weapons aging, and provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balance of resource, including technical staff, hardware, simulation software, and computer science solutions. ASC is now focused on increasing predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (sufficient resolution, dimensionality, and scientific details), and quantifying critical margins and uncertainties. Resolving each issue requires increasingly difficult analyses because the aging process has progressively moved the stockpile further away from the original test base. Where possible, the program also enables the use of high performance computing (HPC) and simulation tools to address broader national security needs, such as foreign nuclear weapon assessments and counter nuclear terrorism.
Over the past several years Pacific Northwest National Laboratory (PNNL) has been actively involved in supporting the U.S. Department of Energy National Nuclear Security Administration Office of Material Management and Minimization (formerly Global Threat Reduction Initiative). The U.S. High- Power Research Reactor (USHPRR) project is developing alternatives to existing highly enriched uranium alloy fuel to reduce the proliferation threat. One option for a high-density metal fuel is uranium alloyed with 10 wt% molybdenum (U-10Mo). Forming the U-10Mo fuel plates/foils via rolling is an effective technique and is actively being pursued as part of the baseline manufacturing process. The processing of these fuel plates requires systematic investigation/understanding of the pre- and post-rolling microstructure, end-state mechanical properties, residual stresses, and defects, their effect on the mill during processing, and eventually, their in-reactor performance. In the work documented herein, studies were conducted to determine the effect of cold and hot rolling the as-cast and homogenized U-10Mo on its microstructure and hardness. The samples were homogenized at 900°C for 48 h, then later annealed for several durations and temperatures to investigate the effect on the material’s microstructure and hardness. The rolling of the as-cast plate, both hot and cold, was observed to form a molybdenum-rich and -lean banded structure. The cold rolling was ineffective, and in some cases exacerbated the as-cast defects. The grains elongated along the rolling direction and formed a pancake shape, while the carbides fractured perpendicularly to the rolling direction and left porosity between fractured particles of UC. The subsequent annealing of these samples at sub-eutectoid temperatures led to rapid precipitation of the ' lamellar phase, mainly in the molybdenum-lean regions. Annealing the samples above the eutectoid temperature did not refine the grain size or the banded microstructure. However, annealing the samples led to quick recovery in hardness as evidenced by a drop in Vickers hardness of 20%. Hot rolling was performed at 650 and 800°C. The hot-rolling mill loads (load separation force) were approximately 40 to 50% less than the cold-rolling for the same reduction and thickness. It was observed that hot rolling the samples with 50% or more reduction in thickness were responsible for dynamic recrystallization in the hot-rolled samples and led to grain refinement. Unlike the cold-rolled samples, the hot-rolled samples did not fracture the carbides and appeared to heal the casting defects. The recovery phenomenon was similar to the cold-rolled samples above the eutectoid temperatures, but owing to the refined grain size, the precipitation of the lamellar phase was far more rapid in these samples and the hardness increased more rapidly than in the cold rolled sample when heated below the eutectoid temperature. The data generated from these rolling efforts has been used to make the process modeling efforts more robust and applicable to all USHPRR partner rolling mills. The flow stress for cold rolling the samples was determined to be between 170-190 ksi, with frictional forces between 0.2 and 0.4 for the PNNL mill. The measured roll separation forces and those simulated using finite element methods for hot and cold rolling for the PNNL rolling mill were in good agreement.
The objective of this project was to determine the feasibility of online deposition of the active layer for thin-film PV modules. The envisioned PV online manufacturing process has a number of discrete unit operations integrated into a single process. Demonstration of feasibility would be deemed successful with the individual demonstration of each of these unit operations and development of the integrated process was not within the scope of this phase.
The U.S. Department of Energy (DOE) is focused on providing a portfolio of technology solutions to meet energy security challenges of the future. Fuel cells are a part of this portfolio of technology offerings. To help meet these challenges and supplement the understanding of the current research, Battelle has executed a five-year program that evaluated the total system costs and total ownership costs of two technologies: (1) an ~80 °C polymer electrolyte membrane fuel cell (PEMFC) technology and (2) a solid oxide fuel cell (SOFC) technology, operating with hydrogen or reformate for different applications. Previous research conducted by Battelle, and more recently by other research institutes, suggests that fuel cells can offer customers significant fuel and emission savings along with other benefits compared to incumbent alternatives. For this project, Battelle has applied a proven cost assessment approach to assist the DOE Fuel Cell Technologies Program in making decisions regarding research and development, scale-up, and deployment of fuel cell technology. The cost studies and subsequent reports provide accurate projections of current system costs and the cost impact of state-of-the-art technologies in manufacturing, increases in production volume, and changes to system design on system cost and life cycle cost for several near-term and emerging fuel cell markets. The studies also provide information on types of manufacturing processes that must be developed to commercialize fuel cells and also provide insights into the optimization needed for use of off-the-shelf components in fuel cell systems. Battelle’s analysis is intended to help DOE prioritize investments in research and development of components to reduce the costs of fuel cell systems while considering systems optimization.
This report describes work on Rapid Conditioning for the Next Generation Melting System under US Department of Energy Contract DE-FC36-06GO16010. The project lead was the Gas Technology Institute (GTI). Partners included Owens Corning and Johns Manville. Cost share for this project was provided by NYSERDA (the New York State Energy Research and Development Authority), Owens Corning, Johns Manville, Owens Illinois, and the US natural gas industry through GTI’s SMP and UTD programs. The overreaching focus of this project was to study and develop rapid refining approaches for segmented glass manufacturing processes using high-intensity melters such as the submerged combustion melter. The objectives of this project were to 1) test and evaluate the most promising approaches to rapidly condition the homogeneous glass produced from the submerged combustion melter, and 2) to design a pilot-scale NGMS system for fiberglass recycle.
This project presents a detailed investigation of a novel functionally graded coating material, pyrochlore oxide, for thermal barrier coating (TBC) in gas turbines used in coal-fired power plants. Thermal barrier coatings are refractory materials deposited on gas turbine components, which provide thermal protection for metallic components at operating conditions. The ultimate goal of this research is to develop a manufacturing process to produce the novel low thermal conductivity and high thermal stability pyrochlore oxide based coatings with improved high-temperature durability. The current standard TBC, yttria stabilized zirconia (YSZ), has service temperatures limited to <1200°C, due to sintering and phase transition at higher temperatures. In contrast, pyrochlore oxide, e.g., lanthanum zirconate (La 2 Zr 2 O 7 , LZ), has demonstrated lower thermal conductivity and better thermal stability, which are crucial to high temperature applications, such as gas turbines used in coal-fired power plants. Indiana University – Purdue University Indianapolis (IUPUI) has collaborated with Praxair Surface Technologies (PST), and Changwon National University in South Korea to perform the proposed research. The research findings are critical to the extension of current TBCs to a broader range of high-temperature materials and applications. Several tasks were originally proposed and accomplished, with additional new opportunities identified during the course of the project. In this report, a description of the project tasks, the main findings and conclusions are given. A list of publications and presentations resulted from this research is listed in the Appendix at the end of the report.
One-step hydrogen generation, using Sorption Enhanced Reforming (SER) technology, is an innovative means of providing critical energy and environmental improvements to US manufacturing processes. The Gas Technology Institute (GTI) is developing a Compact Hydrogen Generator (CHG) process, based on SER technology, which successfully integrates previously independent process steps, achieves superior energy efficiency by lowering reaction temperatures, and provides pathways to doubling energy productivity with less environmental pollution. GTI’s prior CHG process development efforts have culminated in an operational pilot plant. During the initial pilot testing, GTI identified two operating risks- 1) catalyst coating with calcium aluminate compounds, 2) limited solids handling of the sorbent. Under this contract GTI evaluated alternative materials (one catalyst and two sorbents) to mitigate both risks. The alternate catalyst met performance targets and did not experience coating with calcium aluminate compounds of any kind. The alternate sorbent materials demonstrated viable operation, with one material enabling a three-fold increase in sorbent flow. The testing also demonstrated operation at 90% of its rated capacity. Lastly, a carbon dioxide co-production study was performed to assess the advantage of the solid phase separation of carbon dioxide- inherent in the CHG process. Approximately 70% lower capital cost is achievable compared to SMR-based hydrogen production with CO2 capture, as well as improved operating costs.
This project seeks to develop and deploy differentiated 21.5% efficient n-type Si solar cells while reaching the SunShot module cost goal of ≤ $0.50/W. This objective hinges on development of enabling low cost technologies that simplify the manufacturing process and reduce overall processing costs. These comprise of (1) Boron emitter formation and passivation; (2) Simplified processing process for emitter and BSF layers; and (3) Advanced metallization for the front and back contacts.
The Stockpile Stewardship Program (SSP) is an integrated technical program for maintaining the safety, surety, and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational capabilities to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources that support annual stockpile assessment and certification, study advanced nuclear weapons design and manufacturing processes, analyze accident scenarios and weapons aging, and provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balance of resources, including technical staff, hardware, simulation software, and computer science solutions.
The objectives of this project are a 1) Global Competitiveness Analysis of hydrogen and fuel cell systems and components manufactured including 700 bar compressed hydrogen storage system in the U.S., Europe, Asia, and other key areas to be identified to determine the global cost leaders, the best current manufacturing processes, the key factors determining competitiveness, and the potential means of cost reductions; and an 2) Analysis to assess the status of global hydrogen and fuel cell markets. The analysis of units, megawatts by country and by application will focus on polymer electrolyte membrane (PEM) fuel cell systems (automotive and stationary).
Simulant polymer bonded explosives are widely used to simulate the mechanical response of real energetic materials. In this paper, the fracture resistance of a simulant polymer bo nded explosive (PBX) is experimentally investigated. The simulant is composed of 80 wt.% soda lime glass beads (SLGB) and 20 wt.% high impact Polystyrene 825 (HIPS). Brazilian disk tests are performed to characterize the tensile and compressive properties. Fracture toughness and energy tests are performed in the semi - circular bending (SCB) configuration on 80, 81, 82, and 83 wt % SLGB compositions. Digital image correlation is performed to record the surface displacements and calculate surface strains during testing. The m icromechanical behavior of ductile and brittle fracture are evaluated using digital microscopy and scanning electron microscopy of the fracture surface. It is determined that (i) the manufacturing process produces a credible simulant of PBX properties, and (ii) the SCB test measures fracture resistance with a reasonable coefficient of variation.
Particle accelerators produce beams of high-energy particles, which are used for both fundamental and applied scientific research and are critical to the development of accelerator driven sub-critical reactor systems. An effective magnetic shield is very important to achieve higher quality factor (Qo) of the cryomodule of a particle accelerator. The allowed value of field inside the cavity due to all external fields (particularly the Earth’s magnetic field) is ~15 mG or less. The goal of this PhD dissertation is to comprehensively study the magnetic properties of commonly used magnetic shielding materials at both cryogenic and room temperatures. This knowledge can be used for the enhanced design of magnetic shields of cryomodes (CM) in particle accelerators. To this end, we first studied the temperature dependent magnetization behavior (M-H curves) of Amumetal and A4K under different annealing and deformation conditions. This characterized the effect of stress or deformation induced during the manufacturing processes and subsequent restoration of high permeability with appropriate heat treatment. Next, an energy based stochastic model for temperature dependent anhysteretic magnetization behavior of ferromagnetic materials was proposed and benchmarked against experimental data. We show that this model is able to simulate and explain the magnetic behavior of as rolled, deformed and annealed amumetal and A4K over a large range of temperatures. The experimental results for permeability are then used in a finite element model (FEM) in COMSOL to evaluate the shielding effectiveness of multiple shield designs at room temperature as well as cryogenic temperature. This work could serve as a guideline for future design, development and fabrication of magnetic shields of CMs.
Organic solar cells have the potential to offer low-cost solar energy conversion due to low material costs and compatibility with low-temperature and high throughput manufacturing processes. This project aims to further improve the efficiency of organic solar cells by applying a previously demonstrated molecular self-assembly approach to longer-wavelength light-absorbing organic materials. The team at the University of Florida designed and synthesized a series of low-bandgap organic semiconductors with functional hydrogen-bonding groups, studied their assembly characteristics and optoelectronic properties in solid-state thin film, and fabricated organic solar cells using solution processing. These new organic materials absorb light up 800 nm wavelength, and provide a maximum open-circuit voltage of 1.05 V in the resulted solar cells. The results further confirmed the effectiveness in this approach to guide the assembly of organic semiconductors in thin films to yield higher photovoltaic performance for solar energy conversion. Through this project, we have gained important understanding on designing, synthesizing, and processing organic semiconductors that contain appropriately functionalized groups to control the morphology of the organic photoactive layer in solar cells. Such fundamental knowledge could be used to further develop new functional organic materials to achieve higher photovoltaic performance, and contribute to the eventual commercialization of the organic solar cell technology.
Existing commercially available hydrogen storage technologies are largely based on bulky and costly pressure vessels. These pressure vessels come in various forms, ranging from Type I steel cylinders to Type III and Type IV composite wrapped cylinders with metallic or polymer liners. In efforts to increase the pressure vessel storage density and meet DOE hydrogen storage targets, manufacturers are making incremental improvements. This approach alone is unlikely to meet DOE hydrogen storage targets and increase adoption of hydrogen fuel cell vehicles. The project team, led by the Center for Transportation and the Environment (CTE) and consisting of High Energy Coil Reservoirs, LLC (HECR) and The University of Texas at Austin's Center for Electromechanics (UT-CEM), has investigated a transformational hydrogen storage technology using high pressure modulus polymeric pressure vessels. These vessels are constructed by overwrapping an extruded thermoplastic elastomeric resin liner with high performance tensile fiber. This technology is used in commercially available compressed air storage for firefighters. The result is a lightweight, flexible, non-explosive, and non-fragmenting pressure vessel that can be shaped (prior to pressurization) to conform to specific applications. Although this project was funded to investigate the potential for this technology for vehicle applications, a potential significant cost reduction allowed with this approach may make it effective for high pressure ground storage as well. As part of Phase I of this project, the research team demonstrated a Kevlar™ over-braid that achieves a burst pressure in excess of 3.1X the operating pressure of 700 bar. The conformable vessel is able to achieve this pressure rating with reduced weight and cost when compared to Type IV vessels. The researchers also identified two potential resins to serve as the liner of the vessel. These resins have excellent hydrogen barrier properties that could enable a liner thickness of 0.06 inches or less; however, difficulties in manufacturing the core due to the extrusion manufacturing processes required testing with prototype resins as commercially available resins were not found that had the required properties. The team was able to build and test a vessel with one such blend, which outperformed the baseline Hytrel resin materials but did not meet the project hydrogen permeability rate goals.
Very small special purpose reactors (SPRs) are under consideration by various entities for remote installations and communities. This type of plug-and-go resource requires inherently positive safety attributes and sound design. Such reactors may be transportable with fresh fuel to serve as a complete power “battery” and they may even be transportable on short notice after initial use. SPRs could eliminate costly and in some cases dangerous fossil fuel deliveries. Small passively safe reactors could be operated remotely by an offsite operations crew. While use cases for such reactors are currently under development, advanced manufacturing processes should be considered to support reactor economics.
Steam generators of the small modular Very High Temperature Reactor (VHTR) will require use of Alloy 800 and 2.25Cr-1Mo steel in different regions depending on temperature and corrosion resistance requirements. As a result, Dissimilar Metal Welds (DMWs) between these two materials are critical for design, development, and manufacturing of the VHTR. DMWs are also used in many other applications in the power generation and petrochemical industries. Experience has demonstrated that failures of such DMWs can occur prematurely well below the expected creep life of either base metal, and these failures have significant consequences in terms of plant reliability, safety, and economic impact. These DMWs failures are caused by the abrupt change in composition that occurs at the weld interface between the two alloys. In this research, the concept of developing and optimizing Graded Transition Joints (GTJ) was developed through an integrated modeling and experimental approach. With GTJs, the composition is gradually graded between the two alloys, thus eliminating the sharp change in composition that causes failure. Microstructural modeling was first conducted to identify the optimum grade length required for improved resistance to carbon diffusion that is largely responsible for premature failure. Next, GTJs were fabricated and characterized in detail to understand how the microstructure evolves during fabrication and long term aging. Finally, the creep behavior of the GTJs was investigated and compared to that of conventional DMWs to demonstrate the superior creep strength of the GTJs. The results of this research provide significant insight into design, fabrication, microstructural evolution, and resultant performance of GTJs that can be used for reducing or eliminating DMW failures in a number of high temperature applications. The results also demonstrate that the GTJs can be readily fabricated with either conventional or additive manufacturing processes, and detailed guidelines are provided on the length of grades needed for optimal performance. The results of this research benefits the general public by improving the reliability of power generation and petrochemical plants that rely on DMWs for safe and reliable operation to deliver power and other products.
This report summarizes the work and results of NEUP Project #15-8251, "Enhanced Performance Fast Reactors with Engineered Passive Safety System," performed from 2015-2018 at UC Berkeley and Argonne National Laboratory. This project concerns the incorporation of a novel engineered passive safety system, called the Autonomous Reactivity Control (ARC) system, into Sodium-cooled Fast Reactors (SFRs) to improve their transient and economic performance. The first part of this project consisted of fleshing out the basic principles and the manufacturing process for an SFR fuel assembly with the ARC system installed, with the details provided in high-quality, step-by-step CAD drawings. Once the detailed design is laid out, high-fidelity simulations were performed to optimize the dimensions of important ARC system components and to quantify the standalone time-response of ARC systems in a typical SFR environment. These high-fidelity simulations were used to create reduced-order models of ARC system response which could be incorporated into the SAS4A/SASSYS-1 whole-core transient models. In order to accurately account for the time-response of ARC systems in whole-core transient simulations, modifications were made to the SAS4A/SASSYS-1 transient code. These new capabilities were tested and incorporated into the production version of the code, and have been used extensively in this analysis. Before performing whole-core transient calculations, the two reference cores selected for this study to cover a wide design space were simulated and characterized. The two reference cores, (1) a medium-sized oxide-fueled Advanced Burner Reactor and (2) a large metal-fueled Breed-and-Burn core, challenge conventional means of achieving passive safety. Because the two cores vary substantially, simulating the ARC system in both allows for conclusions to be drawn about the applicability of ARC systems in different SFRs. Once both cores were fully characterized, transient calculations were performed to understand the complicated interplay between the ARC system and other inherent reactivity feedback mechanisms. By performing parametric studies of the transient behavior, ARC system designs that best improve transient performance in each core were identified. Once transient improvements were established, the transient calculations were extended to improve reactor economics through design modifications. Upon establishing the potential benefits of ARC system inclusion, the study examines the negative neutronic implications of incorporating ARC systems into the reference cores. The study concludes by discussing a number of knowledge gaps that exist which may have important implications for ARC system implementation. Ultimately, the results of this project indicate that ARC systems may provide an effective means to improve transient performance in certain types of systems. The transient simulations in the oxide Advanced Burner Reactor showed that significant margin to coolant boiling and fuel melting could be gained through the use of a properly designed ARC system, thus improving inherent safety. While oscillatory behavior was induced in the transient response for certain combinations of ARC system parameters, the oscillation-free design space that can be effectively used to improve performance was found to be large, and the additional margin was demonstrated to allow economical improvements to the core design. Conversely, difficulties were encountered in the Breed-and-Burn core due to fundamental aspects of the core design. The combination of a particularly strong positive coolant void feedback and the use of metallic fuel allowed for diverging oscillations to manifest in response to certain transient initiators, and in the end it was found that the current ARC system design could not simultaneously enable passive safety in all transients examined. In order for complete passive safety to be achieved, a mechanism for slowing the reverse actuation of ARC systems is necessary. Regardless, the standard ARC system was able to improve the performance of two out of the three examined transients by increasing the margin to boiling in Loss of Heat Sink transients and avoiding boiling in Transient Overpower accidents. Additionally, no significant barriers to implementation were found, although the issue of tritium production should be closely monitored in any core incorporating ARC systems. Still, a number of technology gaps exist, and these are discussed at the conclusion of the report to recommend directions for future work.