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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 703 records · Page 39

Analysis of Hanford Cast Stone Supplemental LAW using Composition Adjusted SRS Tank 50 Salt Solution

Vitrification is the primary disposition path for Low Activity Waste (LAW) at the Department of Energy (DOE) Hanford Site. A cementitious waste form is one of the alternatives being considered for the supplemental immobilization of the LAW that will not be treated by the primary vitrification facility. Washington River Protection Solutions (WRPS) has been directed to generate and collect data on cementitious or pozzolanic waste forms such as Cast Stone.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Extended Leach Testing of Simulated LAW Cast Stone Monoliths

This revision to the original report adds two longer term leach sets of data to the report and provides more discussion and graphics on how to interpret the results from long-term laboratory leach tests. The leach tests were performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Development of Advanced High Strength Cast Alloys for Heavy Duty Engines

Gray iron has been the primary alloy for heavy duty diesel engine core castings for decades. During recent decades the limitations of gray iron have been reached in some applications, leading to the use of compacted graphite iron in engine blocks and heads. Caterpillar has had compacted graphite designs in continuous production since the late 1980’s. Due to the drive for higher power density, decreased emissions and increased fuel economy, cylinder pressures and temperatures continue to increase. Currently no viable replacement for today’s compacted graphite irons exist at an acceptable cost level. This project explored methods to develop the next generation of heavy duty diesel engine materials as well as demonstrated some results on new alloy designs although cost targets will likely not be met.

36 MATERIALS SCIENCE↗

Construction and Skilled Trades (CAST) Test Preparation, Final Report for period 10/1/2016 - 03/31/2017

Within the energy and utilities sectors, the most significant barrier for consideration and submittal of diverse applicants for skilled labor opportunities is their inability to successfully pass the industry’s Construction And Skilled Trades (CAST) examination. The exam is collectively accepted as the benchmark for prospective candidates and assess if they have the baseline skills and knowledge to apply for skilled positions within those industries. It is an exam that was created by the Edison Electric Institute. Students were taught for a full 40-hr week M-F. We conducted one class in each of the following locations: Philadelphia, Chicago and Washington, DC. The students learned and practiced curriculum prepared by the utility industry for increased success for the examination. They were also taught how to successfully navigate the final barrier of employment opportunity: behavior-based interviewing. They were then directed to the website in order to apply for the positions they desired, and then scheduled to take the exam. We were targeting at least 70% of those who sit for the exam to pass the first time. If they were unsuccessful, candidates could re-test within 3 months. We then sent their resumes directly to the hiring recruiters and managers so that they received prime consideration. Our target number of applicants who were successful in being invited for interviews was 15 candidates.

99 GENERAL AND MISCELLANEOUS↗

Dealloying, Microstructure and the Corrosion/Protection of Cast Magnesium Alloys

The purpose of this project was to develop a greater understanding of micro-galvanic corrosion effects in cast magnesium alloys using both experimental and computational methods. Experimental accomplishments have been made in the following areas of interest: characterization, aqueous free-corrosion, atmospheric corrosion, ionic liquid dissolution, rate kinetics of oxide dissolution, and coating investigation. Commercial alloys (AZ91D, AM60, and AZ31B), binary-phase alloys (αMg-2at.%Al, αMg-5at.%Al, and Mg-8at.%Al), and component phases (Mg, Al, β-Mg, β-1%Zn, MnAl3) were obtained and characterized using energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Full immersion in aqueous chloride was used to characterize the corrosion behavior of alloys. Rotating disc electrodes (RDEs) were used to observe accelerated long-term corrosion behavior. Al surface redistribution for freely corroded samples was analyzed using SEM, EDS, and lithium underpotential deposition (Li UPD). Atmospheric corrosion was observed using contact angle evolution, overnight pH monitoring, and surface pH evolution studies. Ionic liquid corrosion characterization was performed using linear sweep voltammetry and potentiostatic dissolution in 150° choline chloride-urea (cc-urea). Two surface coatings were investigated: (1) Li-carbonate and (2) cc-urea. Li-carbonate coatings were characterized using X-ray photoelectron spectroscopy (XPS), SEM, and aqueous free corrosion potential monitoring. Hydrophobic cc-urea coatings were characterized using contact angle measurements and electrochemical impedance spectroscopy. Oxide dissolution rate kinetics were studied using inductively coupled plasma mass spectroscopy (ICP-MS). Computational accomplishments have been made through the development of Kinetic Monte Carlo (KMC) simulations which model time- and composition-dependent effects on the microstructure due to spatial redistribution of alloying elements during corrosion.

36 MATERIALS SCIENCE↗

Gleeble Compression Tests on As-Cast Alloy 709 Samples

Compression tests were performed on as-cast Alloy 709 (heat 58776-3) using Gleeble ® 3500-GTC system at Oak Ridge National Laboratory (ORNL). The testing temperature range was 900 °C to 1200 °C and the nominal true strain rate range was 0.001/s to 40/s. The tested specimens were delivered to Argonne National Laboratory (ANL) for confirmatory microstructure analysis. The test data were provided to ANL for the construction of the processing map for Alloy 709.

36 MATERIALS SCIENCE↗

FY18 Report: HFIR Fuel Casting Support and Microstructural Feature Examination

An effort to commence conversion of the High Flux Isotope Reactor (HFIR) to a low enriched uranium (LEU) based fuel has been proposed. While recent experience from LEU-10wt%Mo (U-10Mo) monolithic metal fuel production may be leveraged considerably, the significant differences between research fuels requires some degree of strategy reassessment. In that spirit, initial casting trials have been performed at LANL over the last two years in order develop a high quality starting metal ingot.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Report on the completion of the development of processing map from as-cast Alloy 709 materials

This report provides details on the completion of the development of the processing map from the as-cast Alloy 709 materials. The report is a Level 4 deliverable in FY18 (M4NT18AN050502012), under the Work Package NT-18AN05050201, “A709 Development” performed by Argonne National Laboratory, as part of Advanced Structural Materials Program for the Advanced Reactor Technologies (ART). The report describes the development of a processing map to guide the development of hot work regimens for A709. The maps combine high-temperature flow stress measurements, described in a companion report by Oak Ridge National Laboratory, and metallographic observations, described here, into a single diagram that can be used to select hot working parameters to avoid regions of plastic instability and to avoid the development of unfavorable microstructures. This report describes the process of creating the map, provides the final map for A709, and uses the processing map to describe two potential hot work regimens that could be used in processing a DOE round ingot into bar stock.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Outgassing of casted and 3D printed silicones

Outgassing of 3D printed and casted silica-filled silicones was studied using a standard ASTM E-595 procedure and a modified Soreq’s method that allows very sensitive measurements of the outgassing kinetics even at low temperatures, 20 – 50 °C. We studied three different silica-filled silicones, non-porous cased M9787, and 3D printed LL50 and 40P materials. The present report shows that vacuum outgassing products of polysiloxane-based materials include multiple species. In addition to chemisorbed and physisorbed water outgassing, previously studied by TPD, polymer fragments of varying sizes evaporate as well. The chemical composition of the condensable volatile species collected on a Germanium substrate, was analyzed by FTIR. It was shown that all studied materials produce mostly PDMS-based outgassing products that form stable droplet-like structure on the Ge substrate. The highest amount of the condensable volatile species was measured for LL50. Isothermal TGA in nitrogen atmosphere of the LL50 material was compared to the standard vacuum outgassing. The results of TGA showed lower mass loss and higher water regain. The kinetics of the outgassing at relatively low temperatures of 20, 30 and 50 °C was studied using Thermoelectric Quartz Crystal Microbalance (TQCM). The TQCM surface was held at -10 °C to enhance condensation of the outgassed moisture. The analysis presented here, when combined with the extensive previous work on moisture outgassing, provides a better understanding of the aging mechanism of polysiloxane-based materials. In this work we show that outgassing techniques, usually applied for qualification of polymers for space-related applications, may be used as a complementary method to study thermal degradation and aging of silica-based silicones. Our results indicate that the long-term degradation mechanics and thermal degradation products depend primarily on the chemical composition of silicone-based material and only slightly affected by the manufacturing process. Surprisingly, the surface-to-volume ratio of the 3D printed vs. casted/molded materials showed only minor effect on the outgassing kinetic parameters.

36 MATERIALS SCIENCE↗

Investigation of Carbide Inclusions in Cast Uranium [Slides]

Outline - Introduction: The motivations for the project, and some background on inclusions in uranium, and about the samples; Lath Inclusion Morphology: Looking at the morphology of a specific family of carbide inclusions in casting 20; Clustering of Lath Inclusions: Investigating the group behavior of these lath shaped inclusions from the inner to outer edges; Conclusions: Final thoughts on the lath inclusions and future work ideas.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Prototyping and Manufacturing of Magnetic Gearbox Components using Innovations in Castings

In a previous collaboration with Emrgy (CRADA agreement NFE-17-06532), a housing component of Emrgy’s 10 kW gearbox was casted out of aluminum alloys using impression molds prepared using 3D printed techniques. (Henderson, 2018). After comparison with Emrgy’s existing hardware and material testing, the 3D printed impression molds were verified to represent a valid approach to advance technology readiness and commercialize Emrgy’s technology.

13 HYDRO ENERGY↗

LDR Inorganic Spiked Simulants in Pozzolan-Substituted Cast Stone for Hanford Pretreated Low-Activity Tank Waste

Pretreated Low Activity Waste (PTW/LAW) at the Hanford Site, is currently projected for disposition through a cementitious waste form. The current standard formulation, Cast Stone, uses Class F fly ash, blast furnace slag, and Portland cement. However, the future availability of Class F fly ash is uncertain, as many coal-fired power plants—the source of this byproduct—are being decommissioned or converted to natural gas. This issue has prompted research into identifying and evaluating suitable alternative materials to replace fly ash in the cementitious waste forms used by the Department of Energy (DOE). The Savannah River National Laboratory (SRNL) successfully identified four natural pozzolans for the replacement of Class F fly ash in the current Savannah River Site (SRS) low-level waste (LLW) form, Saltstone.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Macro-micro multiscale modeling to assist the design of HPDC Al castings microstructure and alloys for EV super-large body structures (Phase 1)

Implementation of High Pressure Die Casting (HPDC) Aluminum (Al) body structures for high volume electrified vehicles (EV) to improve electric efficiency remains a key strategy within many original equipment manufacturers (OEM)s. In addition to high strength for safety requirements, superior Self Piercing Riveting (SPR) performance is demanded for HPDC Al alloys to be compatible with high volume SPR joining. In this work, it is proposed to extend and validate an existing Contractor finite element multiscale macro-micro modeling approach to quantify the influence of the microstructure of HPDC alloys on the fracture strain/displacement under 3-point bend and clinch testing. The success of this work will allow to replace solution treatment stage with low energy consumption heat treatment (HT) processes, or to design new non heat treatable (NHT) HPDC Al alloys to eliminate HT requirements. Ultimately, this project will facilitate the application of HPDC Al alloys for super-large vehicle structures to significantly reduce vehicle weight and thus improving energy efficiency. The purpose of this project is to extend and validate an existing f

99 GENERAL AND MISCELLANEOUS↗

Casting the Coronal Magnetic Field Reconstruction Tools in 3D Using the MHD Bifrost Model

Quantifying the coronal magnetic field remains a central problem in solar physics. Nowadays, the coronal magnetic field is often modeled using nonlinear force-free field (NLFFF) reconstructions, whose accuracy has not yet been comprehensively assessed. Here we perform a detailed casting of the NLFFF reconstruction tools, such as π -disambiguation, photospheric field preprocessing, and volume reconstruction methods, using a 3D snapshot of the publicly available full-fledged radiative MHD model. Specifically, from the MHD model, we know the magnetic field vector in the entire 3D domain, which enables us to perform a “voxel-by-voxel” comparison of the restored and the true magnetic fields in the 3D model volume. Our tests show that the available π -disambiguation methods often fail in the quiet-Sun areas dominated by small-scale magnetic elements, while they work well in the active region (AR) photosphere and (even better) chromosphere. The preprocessing of the photospheric magnetic field, although it does produce a more force-free boundary condition, also results in some effective “elevation” of the magnetic field components. This “elevation” height is different for the longitudinal and transverse components, which results in a systematic error in absolute heights in the reconstructed magnetic data cube. The extrapolations performed starting from the actual AR photospheric magnetogram are free from this systematic error, while other metrics are comparable with those for extrapolations from the preprocessed magnetograms. This finding favors the use of extrapolations from the original photospheric magnetogram without preprocessing. Our tests further suggest that extrapolations from a force-free chromospheric boundary produce measurably better results than those from a photospheric boundary.

79 ASTRONOMY AND ASTROPHYSICS↗

Plug replaces weld filler as seal in complex casting

Expandable metal plug is inserted to provide a seal to support the mold core with small blocks, referred to as chaplets, during the casting of a complex volute. Weld-warpage and multiple X ray inspection are eliminated by use of this technique.

Goundrey, R. L.↗