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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 55 records · Page 3

Technical Report on NETL's Non Newtonian Multiphase Slurry Workshop: A path forward to understanding non-Newtonian multiphase slurry flows

The Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) sponsored a workshop on non-Newtonian multiphase slurry at NETL’s Morgantown campus August 19 and 20, 2013. The objective of this special two-day meeting of 20-30 invited experts from industry, National Labs and academia was to identify and address technical issues associated with handling non-Newtonian multiphase slurries across various facilities managed by DOE. Particular emphasis during this workshop was placed on applications managed by the Office of Environmental Management (EM). The workshop was preceded by two webinars wherein personnel from ORP and NETL provided background information on the Hanford WTP project and discussed the critical design challenges facing this project. In non-Newtonian fluids, viscosity is not constant and exhibits a complex dependence on applied shear stress or deformation. Many applications under EM’s tank farm mission involve non-Newtonian slurries that are multiphase in nature; tank farm storage and handling, slurry transport, and mixing all involve multiphase flow dynamics, which require an improved understanding of the mechanisms responsible for rheological changes in non-Newtonian multiphase slurries (NNMS). To discuss the issues in predicting the behavior of NNMS, the workshop focused on two topic areas: (1) State-of-the-art in non-Newtonian Multiphase Slurry Flow, and (2) Scaling up with Confidence and Ensuring Safe and Reliable Long-Term Operation.

42 ENGINEERING↗

lmprovements and Path Forward for Regulatory Acceptance of SAS4A/SASSYS-1

In the U.S., a key component of the commercialization of advanced reactors is completion of a license application, which must ultimately be approved by the Nuclear Regulatory Commission (NRC). The NRC’s approval of the license application is contingent on, among other things, satisfactory demonstration of the design basis and response to transient and accident scenarios using accepted codes and methods. This effort seeks to improve the regulatory acceptability of the SAS4A/SASSYS-1 advanced reactor design and safety analysis system software by identifying and addressing gaps in the SAS4A/SASSYS-1 documentation basis that support software qualification and dedication. The software’s unique capabilities to assess inherent fast spectrum feedback effects and passive safety features, which facilitate assessment of key safety metrics, position it as a key licensing tool in the field of sodium-cooled fast reactors (SFR).

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

A Proposed Path Forward for Transportation of High-Assay Low-Enriched Uranium

Many of the advanced reactors that are being designed will use high-assay low-enriched uranium (HALEU) as the reactor fuel. HALEU is fuel that is enriched between 5% – 20% uranium-235. With the change to higher enriched material, the industry will have new challenges with the development and regulatory approval of enrichment and fuel fabrication facilities and suitable transportation packages to support the economic use of HALEU materials. One area of concern relates to ensure sub-criticality of the material during transportation as identified by the Nuclear Energy Institute (NEI). To evaluate the relevant work, experts, and industry perspectives on HALEU, a workshop was organized to share relevant experience and insights into HALEU transportation, handling, and management. At the August 30 and 31, 2018 workshop, NEI and industry provided the following recommendations to DOE and the national lab complex. 1. DOE and the lab complex should communicate and educate the Nuclear Regulatory Commission (NRC) on criticality issues related to HALEU. 2. Idaho National Laboratory (INL) should support work needed to certify package design for the transportation of HALEU. a. Suggest amending the Certificate of Compliance of an existing package used for the shipment of commercial quantities. b. Suggest DOE provide funding to package designer(s) for analysis and engineering work for a package to be submitted to NRC for approval. 3. INL should provide specific, or a range, of the expected impurities that will be present in recycled naval fuel. 4. In the longer term, DOE and the lab complex should increase the availability of criticality benchmark data to further reduce conservatism in package design. In addition, a couple key takeaways were identified, including: 1. Although the labs can provide additional criticality experiments, industry has enough data to license facilities, overpacks, and cylinders. Validation from additional critical experiments to establish less uncertainty in the benchmarks will be helpful. 2. A collective effort from industry is needed to express consistency on how much information exists or is needed related to criticality. Based on interactions with industry, DOE, and national laboratories, it appears that large-volume transportation of fresh HALEU appears feasible from a criticality perspective. Specifically, an initial review of applicable criticality benchmark experiments identified numerous applicable experiments. However, a more thorough review of a realistic transportation package design is suggested. Therefore, the following next steps are proposed: 1. Evaluate a large volume package with uranium dioxide enriched to 20%. Specifically, the GNF-A NPC package was proposed as a potentially viable option. 2. Based on the results of (1), determine if additional package designs and fuel material should be evaluated. 3. Based on the results of (1), determine if additional criticality experiments would be beneficial to improve the margins for criticality due to uncertainties. 4. Determine DOE transportation needs (packages sizes, shielding requirements, handling/operational requirements, and timing of availability) related to HALEU. 5. Continue to interface with NEI and interested industry companies to determine the appropriate time to engage the NRC.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Modeling Salt-Material Interactions in Molten Salt Reactors: Opportunities and Path Forward

A revitalized interest in molten salt reactor technology has resulted in a concerted effort across US based national laboratories and universities to investigate and overcome the remaining scientific and engineering questions facing the industry. This report provides a detailed description of the atomistic modelling techniques that could be employed to investigate the atomic-level forces and behaviors governing salt chemistry and thermodynamics, and the corrosion of container materials in these systems. The molten salt environment is broken down into three unique regions in which atomic behaviors are governed by separate processes and forces. A discussion is given on how each region can be modelled using different computational methods. The objective of the models presented for each region is to understand and quantify the individual atom-to-atom forces driving corrosion processes and changes in salt chemistry. Once these fundamental mechanisms are better understood, larger models, which connect the regions, can be designed to investigate the long-term non-equilibrium behaviors exhibited by these molten salt systems. With a large enough computational effort, employing the modeling techniques discussed in this report to supplement experimental investigations, a greater understanding of the degradation of salt-facing structural materials can be gained, enabling more accurate lifetime prediction, greater safety and regulatory compliance, and faster material innovation.

36 MATERIALS SCIENCE↗

Quantum Optimization: Potential, Challenges, and the Path Forward

Recent advances in quantum computers are demonstrating the ability to solve problems at a scale beyond brute force classical simulation. As such, a widespread interest in quantum algorithms has developed in many areas, with optimization being one of the most pronounced domains. Across computer science and physics, there are a number of algorithmic approaches, often with little linkage. This is further complicated by the fragmented nature of the field of mathematical optimization, where major classes of optimization problems, such as combinatorial optimization, convex optimization, non-convex optimization, and stochastic extensions, have devoted communities. With these aspects in mind, this work draws on multiple approaches to study quantum optimization. Provably exact versus heuristic settings are first explained using computational complexity theory — highlighting where quantum advantage is possible in each context. Then, the core building blocks for quantum optimization algorithms are outlined to subsequently define prominent problem classes and identify key open questions that, if answered, will advance the field. The effects of scaling relevant problems on noisy quantum devices are also outlined in detail, alongside meaningful benchmarking problems. We underscore the importance of benchmarking by proposing clear metrics to conduct appropriate comparisons with classical optimization techniques. Lastly, we highlight two domains – finance and sustainability – as rich sources of optimization problems that could be used to benchmark, and eventually validate, the potential real-world impact of quantum optimization.

97 MATHEMATICS AND COMPUTING↗

Dark SRF, a cavity-based search for the Dark Photon: new exclusion limit and path forward

The dark photon is a hypothesized particle in extension to the Standard Model (SM) that would weakly interact with ordinary SM photons. An effective way to search for hidden sector photons in a laboratory set up is through light-shining-through-wall (LSW) schemes.We present here the first results of Dark SRF, a LSW experiment that leverages ultra-high quality factor superconducting radio frequency (SRF) cavities to search for dark photons. The use of Nb SRF cavities combined with a strict calibration and measurement protocol increased sensitivity to dark photons by several orders of magnitude compared to other LSW experiments, as demonstrated by our new exclusion limit on the dark photon mixing angle.In addition to the results of the search conducted in liquid helium using 1.3GHz SRF cavities, we also present the first steps of the second phase of the experiment, which will take place in a dilution refrigerator using 2.6GHz SRF cavities.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

2024 OES-Environmental 2024 State of the Science Report, Chapter 11: Summary and Path Forward

The 2024 State of the Science report has brought together the most up-to-date information on potential environmental effects of marine renewable energy (MRE) development on marine animals, habitats, and ecosystem processes, as well as social and economic systems, using information that is publicly available as well as expert input. The report has been reviewed by over 56 experts. The reviewers provided in excess of one thousand comments during the drafting of the report that have been addressed in this version. The OES-Environmental country representatives from the 16 participating countries helped to scope the entirety of the report and provided valuable contributions to all chapters. The input from these contributors and reviewers has resulted in the most complete compendium of research and monitoring findings possible. While there is new and exciting research underway that should further illuminate the risks of MRE stressor-receptor interactions in the near future, suppositions and incomplete results from unpublished studies were not included in order to maintain the integrity, and decrease the uncertainty, of the messages in this report

16 TIDAL AND WAVE POWER↗