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Field intensity patterns and comparison of beam widths and directivites of Mills cross and two- directional matrix antenna arrays using crossed- slot antennas
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Carbon Storage Technical Viability Approach is a comprehensive evaluation of potential geologic carbon storage sites that includes classic subsurface resource assessment components such as reservoir suitability in addition to hazard, environmental, social, regulatory, and jurisdiction components that may enhance or hinder successful carbon storage. Data for assessments of technically viable carbon storage span many categories, types; are disparate and numerous. Variables and types of data required to support CS assessments were previously not clearly defined and documented. Contextualizing available data indicates their utility, potential uncertainty, and gaps. This presentation details the Carbon Storage Technical Viability Approach, the associated matrix and database, and initial results from a portion of the national data availability assessment that contextualizes the data available to support carbon storage projects. Presented at the American Association of Petroleum Geologists' Carbon Capture Utilization and Storage (SPE-AAPG-SEG CCUS 2024) conference in Houston, TX, March 11-13, 2024.
The Pacific Northwest National Laboratory (PNNL) located in Richland, Washington, hosted and administered Phase II Flaw Detection Performance Tests in August 2018 that allowed the newly matured ultrasonic guided wave phased-array (GWPA) air-slot NDE sensor—“Hanford-Probe A”—developed by Guidedwave to be evaluated for its flaw detection capability and repeatability. A portion of the Phase II Flaw Detection Performance Tests was performed on a subset of test flaws on which the original GWPA sensor was evaluated during Phase I Sensor Effectiveness Testing (SET) to facilitate a comparison in flaw detection performance between Hanford-Probe A and the original GWPA sensor demonstrated in Phase I. The objective of the performance comparison was to determine the extent to which GWPA sensor design changes impacted the flaw detection performance upon which selection of the sensor technology was originally based for the purpose of determining whether the flaw detection performance of the newly matured Hanford-Probe A GWPA air-slot NDE sensor is at least equal to that of the original GWPA sensor evaluated under Phase I SET. This technical letter report presents the results produced by the new Hanford-Probe A on the Phase I test flaws and the results of the flaw detection performance comparison between Hanford-Probe A and the original GWPA sensor demonstrated in Phase I.
This technical letter report (TLR) summarizes technical efforts focused on assessments of eddy current testing (ET) examinations using various mockups for obtaining baseline surface and subsurface conditions on materials susceptible to primary water stress corrosion cracking (PWSCC). The scope of this work included nondestructive evaluation characterization of weld surfaces on mockups that were identified for application of various surface peening approaches. All of the work reported here was conducted prior to planned peening of these surfaces to evaluate pre-peening conditions, and subsequently compare the baseline ET results with post-peening conditions. The overall objective of this work was to demonstrate the effectiveness of employing ET for detecting near/sub-surface defects on mockups in support of peening assessments for surface stress improvement and mitigation of PWSCC in these materials. The U.S. Nuclear Regulatory Commission has communicated their expectations to industry for eddy current inspections of peened, inlayed, and onlayed dissimilar metal welds and is interested in better understanding detection performance and sensitivity of ET techniques to support the development of a technical foundation for detection and sizing limits, effective ET qualification requirements, alternate inspections or programs for evaluating PWSCC mitigation processes, and development of ET acceptance standards that can be referenced in the appropriate American Society of Mechanical Engineers Section XI Code Case (N-770-X). This TLR provides a technical discussion focused on the ET data obtained, the analysis, and conclusions drawn from surface examinations of various plate standards and actual components extracted from cancelled nuclear power plants.
Complex material behavior is represented by a single equation of product form to account for interaction among the various factors. The factors are selected by the physics of the problem and the environment that the model is to represent. For example, different factors will be required for each to represent temperature, moisture, erosion, corrosion, etc. It is important that the equation represent the physics of the behavior in its entirety accurately. The Multi-Factor Interaction Model (MFIM) is used to evaluate the divot weight (foam weight ejected) from the external launch tanks. The multi-factor has sufficient degrees of freedom to evaluate a large number of factors that may contribute to the divot ejection. It also accommodates all interactions by its product form. Each factor has an exponent that satisfies only two points - the initial and final points. The exponent describes a monotonic path from the initial condition to the final. The exponent values are selected so that the described path makes sense in the absence of experimental data. In the present investigation, the data used were obtained by testing simulated specimens in launching conditions. Results show that the MFIM is an effective method of describing the divot weight ejected under the conditions investigated. The problem lies in how to represent the divot weight with a single equation. A unique solution to this problem is a multi-factor equation of product form. Each factor is of the following form (1 xi/xf)ei, where xi is the initial value, usually at ambient conditions, xf the final value, and ei the exponent that makes the curve represented unimodal that meets the initial and final values. The exponents are either evaluated by test data or by technical judgment. A minor disadvantage may be the selection of exponents in the absence of any empirical data. This form has been used successfully in describing the foam ejected in simulated space environmental conditions. Seven factors were required to represent the ejected foam. The exponents were evaluated by least squares method from experimental data. The equation is used and it can represent multiple factors in other problems as well; for example, evaluation of fatigue life, creep life, fracture toughness, and structural fracture, as well as optimization functions. The software is rather simplistic. Required inputs are initial value, final value, and an exponent for each factor. The number of factors is open-ended. The value is updated as each factor is evaluated. If a factor goes to zero, the previous value is used in the evaluation.
The Mid Atlantic CHP Technical Assistance Partnership (MACHPTAP), managed by The Pennsylvania State University College of Engineering, served the six states in the Mid-Atlantic region (Pennsylvania, New Jersey, Delaware, Maryland, Virginia and West Virginia) plus the District of Columbia. The objective of the Combined Heat and Power Technical Assistance Partnerships (CHP TAPs) was to provide essential support to continue the market development of CHP’s suite of technologies to further the installation of highly efficient and cost effective CHP. The MACHPTAP’s work included education and outreach as well as technical assistance to a variety of stakeholders including end-users (commercial, industrial, institutional and more), state decision makers, electric and gas utilities, trade associations and non-profit organizations. This assistance included evaluating the economic, energy, reliability and environmental value of proposed systems. The CHP TAPs represented multi-state regions and are the CHP experts in the region who provide fact-based, un-biased information on CHP, including technologies, project development, project financing, local electric and natural gas utility interfaces, and related State best practice policies. Specifically, the MACHPTAP objectives were accomplished through taskings in four specific areas: Technical Assistance to end Users which involved engaging potential end-users to identify, evaluate, and technically support prospective CHP projects; Engagement and Education of End Users where the MACHPTAP engaged and educated end users about CHP, its benefits, and DOE resources available, and strategically hosted or participated in webinars, workshops and conferences; Policymaker Education where the MACHPTAP hosted or participated in webinars, one-on-one meetings, workshops, and other forums; and Program Administration, Management and Reporting, which included monthly and quarterly reporting, program meetings and coordination of activities with other regional TAPs. Accomplishments in the four specific project areas included providing direct Technical Assistance to 289 prospective CHP end users, conducting or participating in 82 End User Education events and hosting or participating in 73 Policy Maker Education events. During the contract period, 107 CHP installations were commissioned in the Mid Atlantic region, with a total generation capacity of over 160 megawatts, with an additional 34 sites with a capacity of over 100 megawatts currently in the planning/design/construction phase. Programmatically, all monthly metrics reports and quarterly reports were submitted in a timely manner.
The objective of this study is to evaluate competing lidars for use in an airborne forward-looking system to enable aircraft to avoid the hazards of low altitude wind shear. Information is presented in vugraph form on lidar general requirements, tentative technical requirements, comparison of velocity errors and signal to noise ratios in clear weather for 2.1 and 10.6 micron lidars, a wind shear display, and preliminary results.
The topics discussed are the UAS-NAS project life-cycle and ARMD thrust flow down, as well as the UAS environments and how we operate in those environments. NASA's Armstrong Flight Research Center at Edwards, CA, is leading a project designed to help integrate unmanned air vehicles into the world around us. The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS in the NAS, will contribute capabilities designed to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The project falls under the Integrated Systems Research Program office managed at NASA Headquarters by the agency's Aeronautics Research Mission Directorate. NASA's four aeronautics research centers - Armstrong, Ames Research Center, Langley Research Center, and Glenn Research Center - are part of the technology development project. With the use and diversity of unmanned aircraft growing rapidly, new uses for these vehicles are constantly being considered. Unmanned aircraft promise new ways of increasing efficiency, reducing costs, enhancing safety and saving lives 460265main_ED10-0132-16_full.jpg Unmanned aircraft systems such as NASA's Global Hawks (above) and Predator B named Ikhana (below), along with numerous other unmanned aircraft systems large and small, are the prime focus of the UAS in the NAS effort to integrate them into the national airspace. Credits: NASA Photos 710580main_ED07-0243-37_full.jpg The UAS in the NAS project envisions performance-based routine access to all segments of the national airspace for all unmanned aircraft system classes, once all safety-related and technical barriers are overcome. The project will provide critical data to such key stakeholders and customers as the Federal Aviation Administration and RTCA Special Committee 203 (formerly the Radio Technical Commission for Aeronautics) by conducting integrated, relevant system-level tests to adequately address safety and operational challenges of national airspace access by unmanned aircraft systems, or UAS. In the process, the project will work with other key stakeholders to define necessary deliverables and products to help enable such access. Within the project, NASA is focusing on five sub-projects. These five focus areas include assurance of safe separation of unmanned aircraft from manned aircraft when flying in the national airspace; safety-critical command and control systems and radio frequencies to enable safe operation of UAS; human factors issues for ground control stations; airworthiness certification standards for UAS avionics and integrated tests and evaluation designed to determine the viability of emerging UAS technology. Five Focus Areas of the UAS Integration in the NAS Project Separation Assurance Provide an assessment of how planned Next Generation Air Transportation System (NextGen) separation assurance systems, with different functional allocations, perform for UAS in mixed operations with manned aircraft Assess the applicability to UAS and the performance of NASA NextGen separation assurance systems in flight tests with realistic latencies and uncertain trajectories Assess functional allocations ranging from today's ground-based, controller-provided aircraft separation to fully autonomous airborne self-separation Communications Develop data and rationale to obtain appropriate frequency spectrum allocations to enable safe and efficient operation of UAS in the NAS Develop and validate candidate secure safety-critical command and control system/subsystem test equipment for UAS that complies with UAS international/national frequency regulations, standards and recommended practices and minimum operational and aviation system performance standards for UAS Perform analysis to support recommendations for integration of safety-critical command and control systems and air traffic control communications to ensure safe and efficient operation of UAS in the NAS Human Systems Integration Develop a research test bed and database to provide data and proof of concept for GCS - ground control station - operations in the NAS Coordinate with standards organizations to develop human-factors guidelines for GCS operation in the NAS Certification Define a UAS classification scheme and approach to determining Federal Aviation Regulation airworthiness requirements applicable to all UAS digital avionics Provide hazard and risk-related data to support development of type design criteria and best development practices Integrated Tests and Evaluation Integrate and test mature concepts from technical elements to demonstrate and test viability Evaluate the performance of technology development in a relevant environment (full-mission, human-in-the-loop simulations and flight tests)
The Geothermal Resource Portfolio Optimization and Reporting Technique (GeoRePORT) was developed with funding from the U.S. Department of Energy Geothermal Technologies Office to assist in identifying and pursuing long-term investment strategies through the development of a resource reporting protocol. GeoRePORT provides scientists and nonscientists a comprehensive and quantitative means of reporting: (1) features intrinsic to geothermal sites (project grade) and (2) maturity of the development (project readiness). Because geothermal feasibility is not determined by any single factor (e.g., temperature, permeability, permitting), a site?s project grade and readiness are evaluated on 12 attributes pertaining to geological, technical, or socio-economic feasibility. In this paper, we present case studies showing how GeoRePORT can be used to compare geological, technical, and socio-economic attributes between geothermal systems. The consistent and objective assessment protocols used in GeoRePORT allow for comparison of project attributes across unique locations and geological settings. GeoRePORT case studies presented here outline the geological, socio-economic, and technical features of four individual geothermal sites: Coso, Chena, Dixie Valley, and White Sands Missile Range. The case studies illustrate the usefulness of GeoRePORT in evaluating project risk and return, identifying gaps in reported data, evaluating R&D impact, and gathering insights on successes and failures as applicable to future projects.
A historical overview of the airship, technical and operational characteristics of conventional and hybrid concepts, and the results of a parametric design analysis and evaluation are presented. The lift capabilities of certain buoyant fluids for a hypothetical 16 million cu.ft. volume airship are compared. The potential advanced airship concepts are surveyed, followed by a discussion of the six configurations: conventional nonrigid, conventional rigid, Deltoid (Dynairship), Guppoid (Megalifter), Helipsoid, and Heli-Stat. It is suggested that a partially buoyant Helipsoid concept of the optimum buoyancy ratio has the potential to solve the problems facing future airship development, such as Ballast and Ballast Recovery System, Full Low-Speed Controllability, Susceptibility to Wind/Gusting, Weather/Icing Constraints, Ground Handling/Hangaring, and Direct/Indirect Operating Costs.
Large language models (LLMs) are increasingly capable of answering technical questions, synthesizing domain knowledge, and supporting engineering workflows. For nuclear science and engineering, these capabilities require careful, domain-specific evaluation before they can be credibly incorporated into safety-related activities, regulatory review, or technical decision support. This paper presents preliminary results from benchmarking framework for evaluating LLM capabilities in nuclear contexts. The framework is organized into three evaluation categories: nuclear fundamentals, general dual-use knowledge, and plant specific knowledge. These categories are intended to distinguish general nuclear engineering competence from broader technical reasoning and more context-dependent nuclear knowledge. Initial evaluations focus on nuclear fundamentals using questions representative of the knowledge expected of a nuclear professional engineer. Results indicate that contemporary frontier models perform at a high level and substantially exceed the performance of older model generations, with some models approaching saturation of the current benchmark. These findings suggest both the rapid improvement of LLM capabilities in specialized technical domains and the need for more discriminating evaluation methods. The paper presents the benchmark structure, preliminary model-comparison results, and ongoing work. This work supports development of verifiable, responsible, and safety-conscious methods for assessing AI systems in nuclear engineering applications.
Metal additive manufacturing (AM), or metal 3D printing is an emergent advanced manufacturing method that can create near net shape geometries directly from computer models. This technology can provide the capability to rapidly fabricate complex parts that may be required to enhance the integrity of reactor internals components. Such opportunities may be observed during a plant refueling outage and AM parts can be rapidly custom designed, manufactured and deployed within the outage interval. Additive manufacturing of stainless steel (SS) components can add business benefits on fast delivery on repair hardware, installation tooling, new design prototypes tests, etc. For the nuclear industry, the supply chain is always an issue for reactor service. AM can provide through-life supply chain (40-60 years) for high-value low-volume components. In the meantime, the capability of generating complex geometries and functional gradient materials will improve the performance, reduce the overall component cost, plant asset management cost and increase the plant reliability by the improvement in materials performance in nuclear environments. While extensive work has been conducted regarding additively manufacturing of austenitic SS parts, most efforts focused only on basic attributes such as porosity, residual stress, basic tensile properties, along with components yield and process monitoring. Little work has been done to define and evaluate the material requirements for nuclear applications. Technical gaps exist, which limit this technology adoption in the nuclear industry, which includes high manufacturing cost, unknown risks, limited nuclear related data, lack of specification and qualification methods, and no prior business experience. The main objective of this program was to generate research data to address all these technical gaps and establish a commercial practice to use AM technology in the nuclear power industry. The detailed objectives are listed as follows: (1) Evaluate nuclear related properties of AM 316L SS, including microstructure, tensile properties, impact toughness, stress corrosion cracking (SCC), corrosion fatigue (CF), irradiation effects, and irradiation assisted stress corrosion cracking (IASCC). (2) Understand the correlations among laser processing, heat treatment, microstructure and SCC/irradiation properties; (3) Optimize and improve the manufacturing process to achieve enhanced nuclear application properties; (4) Fabricate, evaluate, qualify and test a prototype reactor component to demonstrate the commercial viability and cost benefit; (5) Create regulatory approval path and commercialization plans for the production of a commercial reactor component.
The design feasibility study is documented of a single cylinder, free piston Stirling engine/linear alternator (FPSE/LA) power module generating 150 kW-electric (kW sub e), and the determination of the module's maximum feasible power level. The power module configuration was specified to be a single cylinder (single piston, single displacer) FPSE/LA, with tuning capacitors if required. The design requirements were as follows: (1) Maximum electrical power output; (2) Power module thermal efficiency equal to or greater than 20 percent at a specific mass of 5 to 8 kg/kW(sub e); (3) Heater wall temperature/cooler wall temperature = 1050 K/525 K; (4) Sodium heat-pipe heat transport system, pumped loop NaK (sodium-potassium eutectic mixture) rejection system; (5) Maximum power module vibration amplitude = 0.0038 cm; and (6) Design life = 7 years (60,000 hr). The results show that a single cylinder FPSE/LA is capable of meeting program goals and has attractive scaling attributes over the power range from 25 to 150 kW(sub e). Scaling beyond the 150 kW(sub e) power level, the power module efficiency falls and the power module specific mass reaches 10 kg/kW(sub e) at a power output of 500 kW(sub e). A discussion of scaling rules for the engine, alternator, and heat transport systems is presented, along with a detailed description of the conceptual design of a 150 kW(sub e) power module that meets the requirements. Included is a discussion of the design of a dynamic balance system. A parametric study of power module performance conducted over the power output range of 25 to 150 kW(sub e) for temperature ratios of 1.7, 2.0, 2.5, and 3.0 is presented and discussed. The results show that as the temperature ratio decreases, the efficiency falls and specific mass increases. At a temperature ratio of 1.7, the 150 kW(sub e) power module cannot satisfy both efficiency and specific mass goals. As the power level increases from 25 to 150 kW(sub e) at a fixed temperature ratio, power module efficiency is seen to increase slightly, but at the expense of increased specific mass. An empirical equation relating power module thermal efficiency as a function of power module specific mass, power output, and temperature ratio is developed. Alternative configurations to the single cylinder, direct coupled linear alternator approach are also evaluated, but are shown to have technical drawbacks that lessen their attractiveness. The dynamic balance assembly mass (moving mass and structure) represents 20 to 30 percent of the total single cylinder power module mass. Joining two modules in a balanced opposed configuration eliminates the need for the balancer, and a hot end junction can be made without significant addition of structural mass. Recommendations are made for evaluation of advanced heat pipe concepts, tests of radial flow heat exchangers, and evaluation of high temperature alternator materials.
The relatively low cost and corrosion resistance of cast austenitic stainless steel (CASS) materials resulted in their extensive use for piping systems in nuclear power plants (NPPs). However, CASS component welds are among the most challenging volumetric examinations required to be performed for detection of potential service degradation. Effective and reliable inspection methods for CASS materials are essential to achieving the objectives of defense-in-depth. A complicating issue is the presence of thermal aging embrittlement, a known degradation mechanism that occurs in CASS NPP materials. Further, while not as yet reported in CASS, many unforeseen instances of cracking in safety-related piping system welds have been experienced in other austenitic materials. Currently, a performance-based method to qualify NDE in CASS is not available. Pacific Northwest National Laboratory (PNNL) has performed nondestructive examination (NDE) research under the sponsorship of the U.S. Nuclear Regulatory Commission (NRC) for over four decades. A primary objective of the research has been to assess the effectiveness and reliability of conventional and advanced NDE methods for the inspection of light-water reactor components. One of the tasks being performed within this framework is to evaluate state-of-the-art technical approaches for examining safety-related nuclear reactor components that pose significant challenges to traditional NDE methods. A specific area of research in this regard is the volumetric examination of coarse-grained weldments and base materials. This report summarizes, compiles, and assesses relevant investigations performed by PNNL and other domestic and international organizations for welds adjacent to CASS components to provide a comprehensive evaluation on this subject. The primary objectives of the report are to assess the overall feasibility for advanced NDE methods to reliably and effectively examine field CASS piping components and to determine if techniques similar to those described in existing standards could be applied to develop performance demonstration requirements for CASS piping components. This report discusses improving the reliability of CASS examinations through the use of advanced low-frequency phased-array techniques, coupled with other “best practice” examination parameters, and makes recommendations for consideration by NRC Staff regarding the development of effective performance-based qualifications for CASS weldments. In addition to the PNNL research documented here, over 230 historical and more recent publications have been reviewed in the development of this document. The report is expected to be a useful resource for engineers and scientists involved in NDE of CASS for purposes of inservice inspection on existing plants during current and extended periods of operation. Finally, researchers and NDE practitioners conducting future investigations to advance the state-of-the-art should find the information contained in this report to be beneficial.
From the mid-1980s to the present, the Department of Energy (DOE) has developed, tested, and deployed diverse bioremediation strategies for chlorinated volatile organic compounds (cVOCs). A systematic review of these projects after decades of activity provides an opportunity to identify crosscutting themes and lessons learned. The knowledge provided by a DOE bioremediation retrospective represents a resource to support current and future bioremediation operations, and future decisions related to cVOC bioremediation. This systematic review examined the design, objectives, performance and outcomes for remediation projects at DOE sites including Savannah River, Hanford, Idaho, Mound and Pinellas. The results were used to identify emergent themes to provide actionable insights. The bioremediation retrospective technical team first developed standardized criteria to support the systematic review. Then, the evaluation was performed using a sequential process that was informed by local technical experts who identified and provided the structured information that served as the basis for the evaluation. The participation of these experts was invaluable to the effort. Importantly, DOE cVOC bioremediation efforts were implemented based on the foundational knowledge developed by U.S. Department of Defense (DoD) strategic and applied environmental technology development and certification programs, as well as technical, policy and regulatory guidance from the U.S. Environmental Protection Agency (EPA), Interstate Technology and Regulatory Council (ITRC), U.S. Geological Survey (USGS), industry, and universities. To maximize the value of the DOE cVOC bioremediation retrospective, the systematic review strategy focused on identifying important DOE-specific experiences, trends and lessons learned that would extend the knowledge available from these other key entities.
NREL is the only DOE national laboratory solely dedicated to advancing energy efficiency (EE) and renewable energy (RE) technologies and applications. Since its inception, NREL has supported both the public and the private sectors in implementing EE and RE systems and strategies to lower energy use and to meet remaining energy needs with resources having minimal environmental impact. NREL is now a sought-after resource for EE, RE, and energy systems integration expertise. CU Boulder is a public university located in Boulder, Colorado, with over 30,000 students. CU is committed to environmental sustainability and is interested in partnering with NREL to explore opportunities for RE on campus and evaluate an RE microgrid. The goal of this project is to assess the technical and economic potential for RE generation at CU and evaluate how RE may be incorporated as part of a microgrid to increase energy resiliency on campus.