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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Enabling Technologies for Ultra-Safe and Secure Modular Nuclear Energy

Sandia National Laboratories and General Atomics are pleased to respond to the Advanced Research Projects Agency-Energy (ARPA-e)’s request for information on innovative developments that may overcome various current reactor-technology limitations. The RFI is particularly interested in innovations that enable ultra-safe and secure modular nuclear energy systems. Our response addresses the specific features for reactor designs called out in the RFI, including a brief assessment of the current state of the technologies that would enable each feature and the methods by which they could be best incorporated into a reactor design.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Identification and Characterization of Thermal Fluid Phenomena Associated with Selected Operating/Accident Scenarios in Modular High Temperature Gas-cooled Reactors

Dominant phenomena are identified and characterized for the loss-of-forced-convection (LOFC) scenario, the depressurized loss-of-forced-convection (DLOFC) scenario, and the moisture ingress scenario with relief valves available scenario. These scenarios are considered for the modular high temperature gas-cooled reactor (MHTGR) baseline design—with both a prismatic core and a pebble-bed core. The objectives of this effort, described in the above paragraph, were achieved by following a methodology identified by the U.S. Nuclear Regulatory Commission (NRC) and recommended in their Regulatory Guide 1.203. The methodology employed is described. For the above scenarios, baseline phenomena identification and ranking tables (PIRTs) generated by a NRC-sponsored effort in 2008 for the LOFC and DLOFC scenarios and a baseline PIRT generated by a Department of Energy-sponsored effort in 2011 by their Next Generation Nuclear Plant (NGNP) Moisture Ingress Assessment Committee were used to identify the dominant phenomena and existing levels-of-knowledge. Ten dominant phenomena (with only medium or low levels-of-knowledge) were identified for the LOFC and DLOFC scenarios including: (1) Inlet plenum stratification and plumes, (2) core coolant flow distribution, (3) radiant heat transfer from the top of the core to the upper vessel head, (4) reactor cavity air circulation and heat transfer, (5) reactor cavity cooling system behavior, (6) decay heat distributions, (7) core effective thermal conductivity, (8) molecular diffusion in air ingress DLOFC, (9) duct exchange flow, (10) phenomena that affect cavity gas composition for air-ingress. Five dominant phenomena, with high levels of knowledge, were identified for the moisture-ingress scenario with relief valves available including: (1) flow through break, (2) moisture level in the primary, (3) transport to moisture monitor, (4) moisture monitor instrument response, and (5) heat removal by shutdown cooling system. These phenomena are discussed and characterized. A listing of experiments—both completed and ongoing—is given with a view toward including data useful for further more detailed examination of the dominant phenomena listed in the previous paragraph. Note that only data for the LOFC and DLOFC scenarios are listed—since the moisture ingress scenario with relief valves available –have been identified as having adequate levels-of-knowledge by the PIRT committee. Finally, a preliminary computational fluid dynamics (CFD) calculation of inlet plenum stratification and plumes is described. Techniques employed for this calculation are typical for preliminary scoping calculations performed to validate numeric tools.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Properties of the Graph Modularity Matrix and its Applications

We study the popular modularity matrix and respective functional used in connection with graph clustering and derive some properties useful when performing vertex aggregation of the associated graph. These properties are employed in the derivation of a multilevel parallel pairwise aggregation algorithm. Some illustrative examples which include algebraic multigrid (AMG) coarsening that follows strong direction of anisotropy in finite element problems as well as comparative performance results of the studied algorithm are presented.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

Cost-Disruptive, Low Impact, Modular Form Factor Low-Head Hyropower System

Littoral Power Systems, Inc. (LPS) is writing a new story when it comes to turning the natural power of water into electricity. h-Modulor™ is a new way of designing and building hydropower plants that addresses the crucial issues of cost, environmental impact and regulatory time frames. For decades hydropower developers, owners and operators have struggled to build new or expanded facilities that didn’t cost so much, were friendlier to the environment and didn’t take so much time to license or build. The problem is particularly acute in smaller installations. The burdensome regulatory pathway for projects under 10MW in capacity have eased the licensing requirements for small hydro projects. But in small projects are still very hard, because capital costs are a much larger percentage of the generation revenues than they are in large facilities. There is an acute need for a cost effective solution. Understanding this need and opportunity, LPS conceived a new type of hydropower equipment – a kit of standard, pre-fabricated modular parts for dam safety, power generation, spill control and other hydropower facility functions to be used to build and operate a hydro plant at substantially lower costs than are currently achievable. This system of prefabricated parts also showed promise to reduce environmental impacts, reduce engineering time involved in the licensing process, and possibly provide a new way for regulators to think about licensing that could lead to reduced regulatory timeframes. Because of this invention’s compelling and intriguing promise the Department of Energy’s (DOE) Water Power Technology Office (WPTO) awarded funding to LPS through the Office of Energy Efficiency and Renewable Energy (EERE) to develop this new type of hydropower equipment to meet a levelized cost of energy (LCOE) goal and analyze it for dam safety. LPS teamed with professional engineers, PhDs, and geotechnical consultants from GZA GeoEnvironental, Inc. (GZA), Alden Research Laboratory (Alden), University of Massachusetts – Dartmouth (UMass-D), the National Renewable Energy Laboratory (NREL) and AECOM. In collaboration with the engineers and managers at the WPTO and EERE they matured the concepts through substantial design shifts. The project exceeded the original goals and delivered designs beyond the proof-of-concept stage backed up by thorough professional engineering analysis of stability, seepage, and structural integrity. A full-scale section with seals successfully retained water in full-head leakage tests. Construction plans and professional engineering cost estimates indicated an LCOE half of the original LCOE goal. A system of these modules is now on track to be used in a 4.5 MW commercial installation.

13 HYDRO ENERGY↗
DOE OSTI2020

Basic Design Layout of a Modular Pumped Hydro Teaching Unit

This work was originally completed in July 2015 as a proposal to Santa Fe Community College (SFCC) for their engineering program and a follow up to a feasibility study completed for the Community College the year earlier as indicated below. The work was ahead of its time and funding was hard to obtain to implement a project. This work is now being formally released for distribution to a wider audience based on the evolving circumstances in greater society that now favor this approach with funding more readily available. Due to the distribution outside of SFCC, specific architectural drawing sets of the pertinent buildings called out in the design have been removed. No changes to the design have been made. The design layout utilizing a building is not meant to limit the implementation of the design. The elevation difference required may be obtained with a building, a small hill, jacking up the upper tank, or similar means. The design presented is a basic design, identifying major components and how they are connected together. The user may change components under their own liability. All local applicable codes and standards must be followed when building an actual unit, under the authority of a responsible engineer or owner. Appropriate measures must be followed to protect people from hazards such as electricity, water pressure, and general construction. A leak test to verify water tightness of the system should be conducted prior to any operations. The vision of this design is to allow a class of 10 to 15 students to construct the assembly within a month or so time period, and then learn to operate the assembly at their school location under the guidance of their instructor. This will allow the students to learn about the practical concept of storing electricity with water, and gain a hands on experience of the real world challenges faced with full Modular Pumped Hydro Projects.

13 HYDRO ENERGY↗
DOE OSTI2018

Highly Integrated Modular LED Luminaire

The objective of the program is to build an integrated luminaire that is capable of modular assembly, with improvements in efficiency in the driver and light engine. Best in class LEDs are assumed. The team will include GE Global Research, in partnership with Stanford University. The goal is to build a highly integrated lighting solution that meets the DOE goals in 2020 for luminaire efficacy and enables low cost manufacturing in the United States.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2021

Advanced Syngas Cleanup Using Radically Engineered Modular Systems

The overall objective of this project was to address key knowledge gaps and develop modular sorbent-based warm syngas cleanup designs that will enable 1- to 5-MW REMS-based plants to be cost-competitive with large state-of-the-art commercial plants utilizing all of our abundant domestic coal reserves. We proposed to develop two potential new desulfurization process designs specifically targeted for REMS plants for combined heat and power or polygeneration from coal gasification. The first design is a modification of our commercially offered dual transport reactor design based Warm-gas Desulfurization Process (WDP) where the transport-reactor regenerator is replaced with a fluidized-bed regenerator. This design leverages the learnings obtained from our pre-commercial demonstration testing of the WDP technology for over 3,000 hours and conclusions from the lessons learned workshop. The second design is a fixed-bed process that leverages the successful composition and chemistry of our WDP sorbent to develop an effective fixed-bed sorbent formulation and fixed-bed process design. These two potential desulfurization process designs have a strong technical likelihood of success and offer the best opportunity to effectively employ design standardization, mass production and advanced manufacturing techniques to enable cost competitiveness for syngas cleanup at smaller scale.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2022

Prefabricated Standard Modular Hydropower Installations for Low-cost Small Hydropower

The goal of the present project was to investigate the potential savings in greenfield hydropower project costs across sites having vastly different characteristics. Littoral Power Systems, Inc. (LPS) undertook the project described herein to explore the promise of Standard Modular Hydropower (SMH) to transform the processes of site identification, conceptual design, detailed design, and construction planning to support low- cost, environmentally attractive development of small hydropower facilities at new stream- reaches. This report includes descriptions of the work to develop these processes, the resulting facility designs achieved using these processes and the projected economics. Installation cost estimates for the resulting conceptual greenfield facility design at two different locations come in at $\$3,419$/kW for Balcony Falls and $\$2,124$/kW for LPS 566. The installation time from site preparation to commissioning-ready is estimated to be 58 weeks for the conceptual facility at Balcony Falls and 42 weeks for the conceptual facility at LPS 566. A real challenge to any hydropower facility – not only the two cases studied here – is that environmental and social conditions can change, and as such, the facility may be required to change. The h-Modulor modules connect uniquely and are structurally independent, enabling site configurations to be changed on the fly, as needed. These results show that LPS's h-Modulor SMH approach delivers an attractive balance between efficiency, economics, and environmental sustainability for small hydro greenfield sites.

13 HYDRO ENERGY↗
DOE OSTI2025

How the Modular Construction Industry Is Changing the Construction Workforce [Slides]

564,000 - that's the number of construction workers the United States lacked in 2023. This is not a new or unfamiliar problem, but high interest rates, housing shortages, and an aging workforce are amplifying the pressure to build faster and recruit new talent. Panelized and modular construction are often touted as a solution to this workforce challenge and have seen year over year increases in market share. While research confirms industrialized construction can increase building efficiencies, researchers at the National Renewable Energy Laboratory (NREL), RMI, Washington State University, Dodge Construction Network and Guidehouse were curious how workers are being impacted both on construction sites, at factories, and all the stages in between.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Unique safety features and licensing requirements of the NuScale small modular reactor

Small modular reactors (SMR) offer a novel approach to the construction and operation of nuclear power plants. The NuScale VOYGR™ plant uses a simplified SMR design that is based on proven light-water reactor technology with substantial improvements in nuclear safety. It consists of a 250 MWt reactor core housed with other primary system components in an integral reactor pressure vessel surrounded by a steel containment vessel, all of which is immersed in a large pool of water that also serves as the ultimate heat sink. At the core of the NuScale safety case are three primary safety systems: the decay heat removal system, the emergency core cooling system, and the containment. The ability of the NuScale Power Module (NPM) passive safety systems to remove core decay heat for an unlimited duration is demonstrated through analysis of a beyond-design-basis extended loss of AC power with no replenishment of water to the ultimate heat sink or operator actions. The NuScale methodology to evaluate an indefinite loss of AC power uses the proprietary NRELAP5 systems analysis computer code. Analysis results show that the reactor coolant system liquid level above the core is maintained and that containment pressure remains below the vessel design pressure. Once full passive air cooling is established, containment pressure and temperature will decrease over time with decreasing core decay heat. NuScale received standard design approval in September 2020 and design certification in January 2023 for its 50 MWe NPM configured as a 12 module plant. NuScale is currently seeking standard design approval to increase its core power to 250 MWt, nominally 77 MWe per module, in a 6-module plant (VOYGR™-6) configuration. The high-level safety of NuScale’s SMR technology is foundational to a new standard of nuclear power plant resilience.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2024

Integrating an Ensemble Reward System into an Off-Policy Reinforcement Learning Algorithm for the Economic Dispatch of Small Modular Reactor-Based Energy Systems

Nuclear Integrated Energy Systems (NIES) have emerged as a comprehensive solution for navigating the changing energy landscape. They combine nuclear power plants with renewable energy sources, storage systems, and smart grid technologies to optimize energy production, distribution, and consumption across sectors, improving efficiency, reliability, and sustainability while addressing challenges associated with variability. The integration of Small Modular Reactors (SMRs) in NIES offers significant benefits over traditional nuclear facilities, although transferring involves overcoming legal and operational barriers, particularly in economic dispatch. This study proposes a novel off-policy Reinforcement Learning (RL) approach with an ensemble reward system to optimize economic dispatch for nuclear-powered generation companies equipped with an SMR, demonstrating superior accuracy and efficiency when compared to conventional methods and emphasizing RL’s potential to improve NIES profitability and sustainability. Finally, the research attempts to demonstrate the viability of implementing the proposed integrated RL approach in spot energy markets to maximize profits for nuclear-driven generation companies, establishing NIES’ profitability over competitors that rely on fossil fuel-based generation units to meet baseload requirements.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2024

Droplet Entrainment in Steam Supply System of Water-Cooled Small Modular Reactors: Experiment and Modeling Approaches

Droplet entrainment in steam-flow is a prominent phenomenon that needs adequate safety and risk analysis of postulated transient and accident scenarios—including experimental investigation and representative modeling and simulation (M&S)—for small modular reactor (SMR) system design and demonstration. This study identifies knowledge gaps by evaluating experimental and computational fluid dynamics modeling approaches to support early-stage reactor system design, testing, and model evaluation. Previous studies reported in the literature for steam-flow entrainment primarily focused on gigawatt capacity pressurized water reactor (PWR) systems. However, entrainment phenomena are even more prominent for PWR-type SMRs due to their more compact integrated designs, which need further research and development. To fill the research gaps, this study provides insight by specifying the phenomena of interest by leveraging the lessons learned from past research, adopting advanced M&S techniques and advanced instrumentation and control. The findings and recommendations are applicable for evaluating steam-flow entrainment models and for designing integral effect test and separate effect test facilities for gaining reactor design approvals.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2022

Carburization Kinetics of Zircalloy-4 and Its Implication for Small Modular Reactor Performance

Carburization of cladding materials has long been a concern for the nuclear industry and has led to the restricted use of high-thermal conductivity fuels such as uranium carbides. With the rise of small modular reactors (SMRs) that frequently implement a graphite core-block, carburization of reactor components is once more in the foreground as a potential failure mechanism. To ensure commercial viability for SMRs, neutron-friendly cladding materials such as Zr-based alloys are required. In this work, the carburization kinetics of Zircaloy-4 (Zry-4), for the temperature range 1073–1673 K (covering typical operating temperatures and off-normal scenarios) are established. The following Arrhenius relationship for the parabolic constant describing ZrC growth is derived: Kp (in μm2/s) = 609.35 exp(−1.505 × 105/RT)). Overall, the ZrC growth is sluggish below 1473 K which is within the operational temperature range of SMRs. In all cases the ZrC that forms from solid state reaction is hypo-stoichiometric, as confirmed through XRD. The hardness and elastic modulus of carburized Zry-4 are also examined and it is shown that despite the formation of a ZrC layer, C ingress in the Zry-4 bulk does not impact the mechanical response after carburization at 1073 K and 1473 K for 96 h.

36 MATERIALS SCIENCE↗
DOE OSTI2018

ABSORPTION CHILLER AND STRATIFIED CHILLED-WATER STORAGE TANK CONFIGURATIONS FOR COUPLING TO A SMALL MODULAR REACTOR

Power maneuvers stemming from time-varying loads imposed on nuclear reactors from diurnal changes in demand and renewable intermittency can be detrimental to the life of the reactor. Temperature swings during power maneuvers result in thermal and mechanical stresses in fuel elements and other reactor components. Thermal Energy Storage (TES) reservoirs can be coupled to reactors to absorb these grid instabilities. Previous work has shown chilled-water storage can help shift cooling loads that contribute to the daily peak electric demand from on-peak to off-peak hours. The objective of this work is to evaluate a stratified chilled-water storage tank as a potential TES reservoir for a Small Modular Reactor (SMR) using absorption chillers for chilled-water production. Simulation results reveal absorption chiller performance is hindered when receiving steam from a tap on the low-pressure turbine. A better configuration involves integrating the absorption chillers into a flash vessel system that is thermally coupled to a sensible heat storage system. The sensible heat storage system maintains reactor thermal output at 100% and matches turbine output with demand while producing enough steam to power four large absorption chillers to charge a stratified chilled-water storage tank, which is used to offset cooling loads in an adjacent facility.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2017

Design of a Sensible Heat Peaking Unit for Small Modular Reactors

Thermal Energy Storage (TES) has been proposed as a load management strategy for Small Modular Reactors (SMRs) deployed on constrained grids and/or hybrid energy systems [1] The three main types of thermal energy storage are sensible heat storage, latent heat storage, and thermochemical storage. Sensible heat storage is the most commercially mature technology [2]. In sensible heat storage, there are two modes of operation: charging and discharging. For a two tank, sensible heat TES System, charging involves taking cold TES fluid from a cold tank, heating it and storing it in a hot tank for later use. Discharge involves taking the hot TES fluid from the hot tank, making use of the heat in some manner, and returning the TES fluid back to the cold tank. The theory, control strategies, and results for operating a two-tank sensible heat storage system in charging mode has been reported previously [3]. In this paper, we examine operation of the TES system in discharge mode as a peaking unit.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗