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At least 1,099 records · Page 61

Scenario Development During Commissioning Operations on the National Spherical Torus Experiment Upgrade

The National Spherical Torus Experiment Upgrade (NSTX-U) will advance the physics basis required for achieving steady-state, high-beta, and high-confinement conditions in a tokamak by accessing high toroidal field (1 T) and plasma current (1.0 - 2.0 MA) in a low aspect ratio geometry (A = 1.6 - 1.8) with flexible auxiliary heating systems (12 MW NBI, 6 MW HHFW). This paper describes progress in the development of L- and H-mode discharge scenarios and the commissioning of operational tools in the first ten weeks of operation that enable the scientific mission of NSTX-U. Vacuum field calculations completed prior to operations supported the rapid development and optimization of inductive breakdown at different values of ohmic solenoid current. The toroidal magnetic field (B_T0 = 0.65 T) exceeded the maximum values achieved on NSTX and novel long-pulse L-mode discharges with regular sawtooth activity exceeded the longest pulses produced on NSTX (tpulse > 1.8s). The increased flux of the central solenoid facilitated the development of stationary L-mode discharges over a range of density and plasma current (Ip). H-mode discharges achieved similar levels of stored energy, confinement (H98y,2 > 1) and stability (beta_N/beta_N-nowall > 1) compared to NSTX discharges for Ip < 1 MA. High-performance H-mode scenarios require an L-H transition early in the Ip ramp-up phase in order to obtain low internal inductance (li) throughout the discharge, which is conducive to maintaining vertical stability at high elongation (kappa > 2.2) and achieving long periods of MHD quiescent operations. The rapid progress in developing L- and H-mode scenarios in support of the scientific program was enabled by advances in real-time plasma control, efficient error field identification and correction, effective conditioning of the graphite wall and excellent diagnostic availability.

Error field correction↗

High-bandwidth image-based predictive laser stabilization via optimized Fourier filters

Controlling the delivery of kHz-class pulsed lasers is of interest in a variety of industrial and scientific applications, from next-generation laser-plasma acceleration to laser-based x-ray emission and high-precision manufacturing. The transverse position of the laser pulse train on the application target is often subject to fluctuations by external drivers (e.g., room cooling and heating systems, motorized optics stages and mounts, vacuum systems, chillers, and/or ground vibrations). For typical situations where the disturbance spectrum exhibits discrete peaks on top of a broad-bandwidth lower-frequency background, traditional PID (proportional-integral-derivative) controllers may struggle, since as a general rule PID controllers can be used to suppress vibrations up to only about 5%–10% of the sampling frequency. Here, a predictive feed-forward algorithm is presented that significantly enhances the stabilization bandwidth in such laser systems (up to the Nyquist limit at half the sampling frequency) by online identification and filtering of one or a few discrete frequencies using optimized Fourier filters. Furthermore, the system architecture demonstrated here uses off-the-shelf CMOS cameras and piezo-electric actuated mirrors connected to a standard PC to process the alignment images and implement the algorithm. To avoid high-end, high-cost components, a machine-learning-based model of the piezo mirror’s dynamics was integrated into the system, which enables high-precision positioning by compensating for hysteresis and other hardware-induced effects. A successful demonstration of the method was performed on a 1 kHz laser pulse train, where externally-induced vibrations of up to 400 Hz were attenuated by a factor of five, far exceeding what could be done with a standard PID scheme.

Natal, Joseph↗

Geothermal Case Studies

The US Geological Survey (USGS) resource assessment (Williams et al., 2009) outlined a mean 30GWe of undiscovered hydrothermal resource in the western US. One goal of the Geothermal Technologies Office (GTO) is to accelerate the development of this undiscovered resource. The Geothermal Technologies Program (GTP) Blue Ribbon Panel (GTO, 2011) recommended that DOE focus efforts on helping industry identify hidden geothermal resources to increase geothermal capacity in the near term. Increased exploration activity will produce more prospects, more discoveries, and more readily developable resources. Detailed exploration case studies akin to those found in oil and gas (e.g. Beaumont, et al, 1990) will give operators a single point of information to gather clean, unbiased information on which to build geothermal drilling prospects. To support this effort, the National Renewable Energy laboratory (NREL) has been working with the Department of Energy (DOE) to develop a template for geothermal case studies on the Geothermal Gateway on OpenEI. In fiscal year 2013, the template was developed and tested with two case studies: Raft River Geothermal Area (http://en.openei.org/wiki/Raft_River_Geothermal_Area) and Coso Geothermal Area (http://en.openei.org/wiki/Coso_Geothermal_Area). In fiscal year 2014, ten additional case studies were completed, and additional features were added to the template to allow for more data and the direct citations of data. The template allows for: Data - a variety of data can be collected for each area, including power production information, well field information, geologic information, reservoir information, and geochemistry information. Narratives ? general (e.g. area overview, history and infrastructure), technical (e.g. exploration history, well field description, R&D activities) and geologic narratives (e.g. area geology, hydrothermal system, heat source, geochemistry.) Exploration Activity Catalog - catalog of exploration activities conducted in the area (with dates and references.) NEPA Analysis ? a query of NEPA analyses conducted in the area (that have been catalogued in the OpenEI NEPA database.) In fiscal year 2015, NREL is working with universities to populate additional case studies on OpenEI. The goal is to provide a large enough dataset to start conducting analyses of exploration programs to identify correlations between successful exploration plans for areas with similar geologic occurrence models.

15 GEOTHERMAL ENERGY↗

Zero-CO Residential Natural Gas Furnace

Residential natural gas furnaces are widely used in the US homes. Manufacturers dedicate significant design and testing resources to meet requirements of design standards. One area of these standards is controlling flue gas carbon monoxide (CO) emissions. To more effectively reduce CO emissions at the flue, we developed a novel catalyst-assisted approach that integrated a low Pt/Rh loading acidic gas reduction (AGR) catalyst with three-way catalyst (TWC) or diesel oxidation catalyst (DOC) components. Compact catalysts were fabricated and assembled into tubular components, which can be seamlessly incorporated into the primary heat exchanger of a representative commercially available condensing furnace. The retrofitted furnace was demonstrated and tested following ANSI/ASHRAE Standard 103-2017. Experimental results showed that both AGR/TWC and AGR/DOC configurations achieved near-zero CO emissions under steady-state and cold-start conditions, compared with up to 500 ppm at a cold start and 17 ppm in a steady state in the OEM furnace. The catalyst-assisted furnaces also exhibited an annual fuel utilization efficiency improvement of more than 1.5% relative to the baseline unit, with a manageable pressure drop of 2.0−2.5 in. of water column. These results demonstrate that the catalyst-assisted approach can effectively eliminate CO emissions and improve energy efficiency. The technology has broad applicability for residential and commercial gas-fired heating systems.

Gao, Zhiming [ORNL] (ORCID:0000000271397995)↗

NREL Delivers In-Home HVAC Efficiency Testing Solutions (Fact Sheet)

Researchers at the National Renewable Energy Laboratory (NREL) have recently developed two simple in-home efficiency test methods that can be used by technicians, researchers, or interested homeowners to verify the correct operation and energy efficiency of a home?s air conditioning equipment.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Playing Hot and Cold: How Can Russian Heat Policy Find Its Way Toward Energy Efficiency?

The Russian district heating has a large energy-saving potential, and, therefore, need for investments. The scale of needed investments is significant: the government estimates that 70 percent of the district heating infrastructure needs replacement or maintenance, a reflection of decades of under investment. Government budgets will be unable to cover them, and iInvolvingement ofthe private industry will be critical to attracting the necessary investementis necessary. For private parties to invest in district heating facilities across Russia, and not only in pockets of already successful enterprises, regulators have to develop a comprehensive policy that works district heating systems under various conditionscost-reflective tariffs, metering, incentives for efficiency and social support for the neediest (instead of subsidies for all).

Roshchanka, Volha↗

Environmental Assessment Lakeview Geothermal Project

The Town of Lakeview is proposing to construct and operate a geothermal direct use district heating system in Lakeview, Oregon. The proposed project would be in Lake County, Oregon, within the Lakeview Known Geothermal Resources Area (KGRA). The proposed project includes the following elements: Drilling, testing, and completion of a new production well and geothermal water injection well; construction and operation of a geothermal production fluid pipeline from the well pad to various Town buildings (i.e., local schools, hospital, and Lake County Industrial Park) and back to a geothermal water injection well. This EA describes the proposed project, the alternatives considered, and presents the environmental analysis pursuant to the National Environmental Policy Act. The project would not result in adverse effects to the environment with the implementation of environmental protection measures.

15 GEOTHERMAL ENERGY↗

Energy Efficiency for the Nunamiut People

The goal of this project is to upgrade existing building facilities owned by Nunamiut Corporation in Anaktuvuk Pass, AK. The upgrades mentioned will include lighting, heating system, insulation and smart control units designed to increase the energy efficiency of Village Corporation owned buildings.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Building America Expert Meeting Report: Hydronic Heating in Multifamily Buildings

This expert meeting was presented by the ARIES Collaborative, and discussed cost-effective controls and distribution retrofit options for hot water and steam space heating systems in multi-family buildings with the goals of reducing energy waste and improving occupant comfort.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Zero Energy Ready Home Multifamily Case Study Analysis

Two multifamily buildings planned in Climate Zone 4 were analyzed to determine the cost, energy and performance implications of redesigning them to comply with Zero Energy Ready Home, a recognition program of the U.S. Department of Energy. Energy modeling was conducted on one representative apartment in each building using BEopt. Construction costs were obtained from the developer and subcontractors to determine savings and cost increases over ENERGY STAR. It was found that seven items would be necessary to change to comply with ZERH criteria when starting from the original design which was compliant with ENERGY STAR version 3.0. Design changes were made to the exterior walls, domestic water heating system, duct protection, duct design, garage ventilation, and pest control to comply with ZERH requirements. Energy impacts of upgrading from the original design to ZERH resulted in 2 to 8% reduction in modeled source energy consumption, or 1.7 to 10.4 MMBtu per year, although the original design was already about 8% better than a design configured to minimum ENERGY STAR criteria. According to the BEopt analysis, annualized energy related costs of the ZERH design were slightly higher for the apartment and slightly lower for the townhome when compared to the original design.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

TA-16-306: A Plastics Components Development Facility (Volumes 1 & 2)

The U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA), Los Alamos Field Office (Field Office), has prepared final documentation for the resolution of adverse effects to Building 306 in Technical Area (TA) 16 at Los Alamos National Laboratory (LANL or the Laboratory). This documentation is being submitted to the New Mexico State Historic Preservation Officer (SHPO). TA-16-306 was determined eligible for listing in the National Register of Historic Places (Register) in 1995 in the report, TA-16 Heating System Replacement (LA-CP-95-0180). TA-16- 306 was identified as an excess property to be decontaminated, decommissioned, and demolished by the LANL Footprint Reduction Program in fiscal year 2021, an adverse effect to Register eligible building 16-306 requiring mitigation. To bring a resolution to the adverse effects to Building TA-16-306, the Field Office initiated consultation with the SHPO on December 4, 2017. The New Mexico Historic Preservation Division concurred with the mitigation actions outlined in the Programmatic Agreement among the U.S. Department of Energy, National Nuclear Security Administration, Los Alamos Field Office, the New Mexico State Historic Preservation Office, and the Advisory Council on Historic Preservation Concerning Management of Historic Properties of Los Alamos National Laboratory, Los Alamos, New Mexico (PA) in correspondence dated January 30, 2018. The PA states in Appendix D.2.A that adverse effects to Register-eligible buildings and structures will be resolved according to the procedures defined in A Plan for the Management of the Cultural Heritage at Los Alamos National Laboratory, New Mexico (CRMP) (LA-UR-19-21590, formerly LA-UR-15-27624) and within the PA itself. Volume 2 contains a collection of photos of building TA-16-306 with index.

42 ENGINEERING↗

IHE DDT Qualification Tests (FY2020-FY2021)

A DDT tube test was designed to meet all requirements established in the new DOE IHE qualification standard. Ten tests were successfully executed with PBX 9502 as a demonstration of the design, assembly, heating system, and methods, and to establish a baseline set of test results with an existing IHE. The explosive response in all tests was low violence (as anticipated). This report contains detailed design drawings, assembly instructions and procedures for future execution of the qualification test series, and makes recommendations for minor improvements.

42 ENGINEERING↗

Report on the Second MPEX User Research Forum

The Material Plasma Exposure eXperiment (MPEX) User Research Forum (MURF), a 2 day workshop, was held virtually on September 13–14, 2021, to seek community input for MPEX, a new high-power linear plasma device that is currently being built at Oak Ridge National Laboratory (ORNL). This was the second MURF workshop. The first MURF workshop was held in October 2019 in La Jolla, California, and focused exclusively on the definition of the surface analysis station for MPEX. MPEX is designed to address crucial R&D gaps in plasma material interactions (PMI) for future fusion reactors. The MPEX plasma source and heating systems will allow plasma exposures of plasma-facing materials and components to prototype fusion reactor divertor plasma conditions. The MPEX design accommodates the introduction of previously neutron-irradiated materials for fusion reactor-relevant plasma exposures. This capability will be unique worldwide. The US fusion program has advocated for such a device in numerous community reports in recent years, and now ORNL is building this new device. MPEX is a Major Item of Equipment project executed by the US Department of Energy’s Office of Science Fusion Energy Sciences.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

End-Use Savings Shapes Measure Documentation: Heat Pump Rooftop Units

The heat pump rooftop units (RTUs) measure replaces gas furnace and electric resistance RTUs with high-efficiency heat pump rooftop units (HP-RTUs). The HP-RTUs are intended to be top-of-the line, including high-efficiency fans and heat pump systems. The fans are variable speed, allowing the HP-RTUs to operate as single-zone variable air volume systems. The heat pumps are also variable speed, allowing for high part load performance. All schedules in the existing RTUs are transferred to the new HP-RTUs for consistency. Furthermore, any energy efficiency features in the existing baseline RTUs such as energy recovery or economizers are also transferred to the new HP-RTUs for consistency. This measure is applicable to approximately 45% of the ComStock floor area. The HP-RTU measure demonstrates 10.3% total site energy savings (449 trillion British thermal units [TBtu]) for the U.S. commercial building stock modeled in ComStock.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Electrifying New York’s Affordable Housing

Enterprise Community Partners (Enterprise) joined forces with the Association for Energy Affordability (AEA), with support from the New York City Department of Housing Preservation and Development (HPD) and New York State Homes and Community Renewal (HCR). Through this 3-year pilot project, the project partners collaborated to develop tools and processes that efficiently utilize New York State Weatherization Assistance Program (WAP) funding to both improve energy efficiency through weatherization and to convert to clean heating systems through electrification. We developed and piloted this approach on five multifamily dwelling buildings, totaling 154 units in New York City, using the energy audit protocol that was developed as part of this project. Our goal was to develop a basis of knowledge for pursuing similar retrofits nationwide.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Activation of Thermal Insulation and Contamination Prevention

The goals of this paper are to enhance the understanding of the potential activation and contamination hazards from the use of insulating materials in the Molten Chloride Reactor Experiment and to foster safer work environments through informed decision-making and strategic planning. It was written to resolve a gating comment from the core heating system preliminary design review. The largest dose expected from the considered insulation materials is about 0.1 mrem per year from Pyrogel. Although Cerablanket stood out among the insulation materials for encouraging ALARA practices, it has a higher thermal conductivity. At low power levels, focusing on reducing the generation of dust from ERD activities may be more effective for reducing the potential spread of contamination than changing the insulating material type. However, regardless of the material chosen, PPE and safety conscious procedural practices can help reduce the production and spread of activated dust––thus minimizing the radiological hazard to workers.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN↗

Impact analysis of heating electrification in US buildings with geothermal heat pumps

Few studies have investigated the impacts of large-scale deployment of geothermal heat pumps (GHPs, also called ground source heat pumps) on the electric grid. GHPs utilize the ground as a heat source to warm buildings more efficiently than other space-heating systems. The coupling with the ground offers seasonal thermal storage so that GHPs can also cool buildings in summer more efficiently than other space-cooling systems. This study simulated the performance of GHP systems for various commercial and residential buildings in 15 climate zones in the United States. Combined with the latest End-Use Load Profiles of the US building stock and grid modeling, this study aims to assess the impacts of a national deployment of GHP systems on the US electric grid in terms of energy consumption, emissions, and operational resilience. The preliminary results show that the GHP deployment can save 429 billion kWh of electricity (a 19% reduction from baseline) and reduce carbon emissions by 496 million tons per year (a 31 % reduction from baseline). A geographical view of the results indicates that retrofitting existing HVAC systems with new GHP systems can lead to further reductions in annual electricity consumption and peak electricity demand in the southern regions of the United States than in other parts of the country. On the other hand, GHP retrofits result in higher percentages of site energy savings and carbon emission reduction in the north (cold climates) than in the south (warm climates).

Liu, Xiaobing↗

A Rapid Sintering Method for Cerium Nitride Pellet: A Uranium Mononitride Surrogate

Uranium mononitride (UN) is a candidate fuel material for light water reactors with higher uranium (U) loading and thermal conductivity than uranium dioxide (UO 2 ). However, the sintering of UN pellets is challenging as the UN powder particles oxidize rapidly at high temperatures unless the oxygen concentration is extremely low. Oxidation during sintering either reduces the relative density of the sintered UN pellet or disintegrates the sintered UN pellet to powder. To address this problem, the present work developed a rapid sintering method for producing highly densified UN surrogate pellets with minimal oxidation. Cerium nitride (CeN) is used as a surrogate for UN to reduce radiation hazards. With the custom-developed fast-heating system, the sintering process was completed within 150 s. The sintering atmosphere was flowing nitrogen (N 2 ). The sintered CeN pellet density was 95% of the theoretical density (TD) or higher. The microstructure was uniform with a 10–25 µm grain size as demonstrated by scanning electron microscopy (SEM) and contained trivial levels of oxides as demonstrated by X-ray diffraction (XRD). The resultant pellets indicate that the rapid sintering method is a promising method to make UN fuel pellets with equivalent or higher density to pellets made by conventional sintering methods, while also being more efficient in time and costs.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗