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At least 1,531 records · Page 85

Versatile Heat Transfer Module

Development of micro-reactors that can be easily transported to remote areas for civilian or military applications is an immediate focus of U.S. nuclear industry and therefore is being pursued by multiple reactor vendors (e.g. HolosGen LLC, Westinghouse, Ultra Safe Nuclear Corporation, URENCO, etc.) and actively supported by DOE-NE, DOE-ARPA-E and by the Department Of Defense (DoD). Very-high-temperature gas-cooled (VHTR) and heat pipe cooled reactor technologies are regarded as promising concepts for microreactors applications since they enable compact power conversion systems and display beneficial inherent safety features. Development of microreactors with enhanced performance must be supported by innovations in nuclear technologies. Several technologies being developed by the microreactor industry are being revisited with material technologies developed at the Argonne National Laboratory (ANL). Innovative high-temperature compatible solutions are developed to enable advanced thermal-spectrum microreactor designs featuring improved neutronics performance at high-temperature operating conditions to enable high thermal efficiency and economic competitiveness. This report focuses on the Versatile Heat Transfer Module (VHTM) technology that is developed at ANL for heat-transfer in thermal-spectrum microreactors. This technology is built on a liquid alkali metal heat pipe concept while leveraging advanced nuclear material technologies for high-temperature applications at reduced neutronic penalty with potential improvement in inherent safety behavior. The VHTM can be applied to design high-temperature thermal-spectrum microreactor systems with reduced size, weight, uranium enrichment, or increased lifetime. The INFINIT technology deriving from the VHTM enables design of a highly compact long-life microreactor concept for fission surface power (FSP). Demonstration of multiphysics modeling capability was also completed to showcase the added inherent safety benefits obtained with this concept. The VHTM technology remain at an early development stage with low Technology Readiness Level and Manufacturing Readiness Level. The current demonstration of these technologies has focused on manufacturing capability, on performance of the hydrogen diffusion barrier under thermal cycling, while radiation tolerance demonstration is planned. The next step of the demonstration plan will be the assembly of miniature VHTM for high-temperature testing, which can be used as a prototype for future pilot scale demonstration. Such research is critical to pursue development of these technologies that have the clear potential to significantly improve the performance of currently investigated micro-reactors systems.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Lighting in Senior Care Centers: Comparing Tunable LED Systems to Conventional Lighting Systems in Four Senior Care Centers

This study was initiated to contribute to evidence-based practices for tunable light-emitting diode (LED) lighting upgrades in the future. The report summarizes Pacific Northwest National Laboratory (PNNL) evaluations of lighting conditions in four senior care centers in Wisconsin including energy savings analysis and non-image forming (NIF) response metric calculations.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Volume 6: Experiment Facility Spectrum Tailoring (HFIR Futures – Enhanced Capabilities Series)

In-core irradiation experiment research, such as materials and fuels irradiation research and radioisotope production, is one of the primary missions of Oak Ridge National Laboratory’s (ORNL) versatile High Flux Isotope Reactor (HFIR). In support of the HFIR-Sustaining and Enhancing Neutron Science (SENSe) Initiative, a technically diverse group of ORNL irradiation research subject matter experts formed the Spectrum Tailoring Working Group, with the goal of developing a compendium of experiment facility concepts to enhance irradiation experiment conditions via neutron spectrum tailoring capabilities. The purpose of this report is to document the concepts developed in FY22 and the associated scientific justifications, identify potential facility sponsors, and estimate costs and schedules for each concept. This report documents the efforts performed in FY22, which may continue in FY23 or later pending the direction of the HFIR-SENSe Initiative and the interested sponsors.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Electrical Infrastructure Cost Model for Marine Energy Systems

The National Renewable Energy Laboratory's Electrical Infrastructure Cost Model is an Excel-based tool designed to estimate the electrical infrastructure costs of marine energy components and subsystems. It incorporates data collected from offshore wind projects, utility projects, and other relevant sources to provide accurate and comprehensive cost projections. With its user-friendly interface, the model allows users to input various parameters related to the system array, electrical cables, and substations. By leveraging industry data, cost trends, and technological advancements, the model generates outputs that include system array sizing, electrical cable specifications and costs, substation specifications and costs, and total electrical infrastructure costs. One of the notable strengths of the model is its flexibility in covering multiple-orders-of-magnitude scaled systems, accommodating projects ranging from proof-of-concept or pilot-scale installations to large-scale offshore systems. By collecting data largely from offshore wind reports and utility projects, the model incorporates real-world conditions and accounts for industry-specific factors. It incorporates cost trends and sizing relationships to deliver cost estimations for electrical infrastructure components, such as electrical cables and substation equipment.

16 TIDAL AND WAVE POWER↗

Viscoelastic Modeling of Polymers in ALEGRA with the GAP Model

The Glassy Amorphous Polymer (GAP) model is a viscoelastic/plastic model developed at Los Alamos National Laboratory to accurately model a variety of polymers across a wide range of conditions and loading rates, including shock loading. In the present report we introduce and assess this model, newly implemented in the ALEGRA shock and multiphysics code, using a series of verification and application-related validation problems. We describe the mathematical and theoretical formulation of the model, as well as its implementation in ALEGRA, in detail. We provide verification results that assess the model implementation against published computational results, as well as validation results which we compare to existing experimental results when possible. These comparisons instill confidence in the implementation and indicate that the addition of the GAP model to the ALEGRA code provides users with a high-fidelity polymer modeling capability that is capable of recreating complex polymer phenomena.

36 MATERIALS SCIENCE↗

Developing an Analytical Framework for Cumulative Effects

The extended dry storage scenario for spent nuclear fuel (SNF) in the United States introduces the possibility of more than one transportation campaign to move the SNF from its point of origin to one or more interim storage facilities before it reaches its final destination. While the structural integrity of SNF and its storage and transportation systems are often evaluated under single event loading conditions, the reality is that a single SNF system will experience multiple structural loading events during its life cycle, the number and severity of which will depend on its individual circumstances. SNF systems will also be subjected to environmental exposure that will affect their temperature and the potential for cracks to develop in the SNF canister walls. Considered separately, many different events and scenarios might be strong enough to challenge the integrity of SNF cladding and the storage and transportations canisters that contain SNF. But considered together, over the full life cycle of an SNF system, there is the possibility that individual low-magnitude events could cause enough incremental damage to components of the SNF system to challenge its structural integrity if the time span is long enough or if the life cycle includes a sufficient number of loading events. The concern is that the cumulative effect of relatively small mechanical loads, thermal stresses, or cracking can add up to conditions that could compromise SNF or its containment structures. This report is a first step in establishing an analysis framework for evaluating these cumulative effects.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Fuel Performance Analysis of Fast Flux Test Facility MFF-3 and -5 Fuel Pins Using BISON with Post Irradiation Examination Data

Using the BISON fuel-performance code, simulations were conducted of an automated process to read initial and operating conditions from the Pacific Northwest National Laboratory (PNNL) database and reports, which contain metallic-fuel data from the Fast Flux Test Facility (FFTF) MFF Experiments. This work builds on previous modeling efforts involving 1977 EBR-II metallic fuel pins from experiments. Coupling the FFTF PNNL reports to BISON allowed for all 338 pins from MFF-3 and MFF-5 campaigns to be simulated. Each BISON simulation contains unique power and flux histories, axial power and flux profiles, and coolant-channel flow rates. Fission-gas release (FGR), fuel axial swelling, cladding profilometry, and burnup were all simulated in BISON and compared to available post-irradiation examination (PIE) data. Cladding profilometry, FGR, and fuel axial swelling simulation results for full-length MFF metallic pins were found to be in agreement with PIE measurements using FFTF physics and models used previously for EBR-II simulations. The main two peaks observed within the cladding profilometry were able to be simulated, with fuel-cladding mechanical interaction (FCMI), fuel-cladding chemical interaction (FCCI), and thermal and irradiation-induced creep being the cause. A U-Pu-Zr hot-pressing model was included in this work to allow pore collapse within the fuel matrix. This allowed better agreement between BISON-simulated cladding profilometry and PIE measurements for the peak caused by FCMI. This work shows that metallic fuel models used to accurately represent fuel performance for smaller EBR-II pins may be used for full-length metallic fuel, such as FFTF MFF assemblies and the Versatile Test Reactor (VTR). As new material models and PIE measurements become available, FFTF MFF assessment cases will be reassessed to further BISON model development.

36 MATERIALS SCIENCE↗

Detection techniques for tenuous planetary atmospheres

The development of new types of detectors for analysis of planetary atmospheres is discussed. Initially, the interest was in detectors for use under partial vacuum conditions; recently, the program has been extended to include detectors for use at one atmosphere and adsorption systems for control and separation of gases. Results to date have included detector for O2 and H2 under partial vacuum conditions. Experiments on detectors for use at high pressures began in 1966; and systems for CO, H2, and O2 were reported in 1967 and 1968. In 1968 studies began on an electrically controlled adsorbent. It was demonstrated that under proper conditions a thin film of semiconductor material could be electrically cycled to absorb and desorb a specific gas. This work was extended to obtain quantitative data on the use of semiconductors as controllable adsorbents.

Hoenig, S. A.↗

A numerical method of detecting singularity

A numerical method is reported which determines a value C for the degree of conditioning of a matrix. This value is C = 0 for a singular matrix and has progressively larger values for matrices which are increasingly well-conditioned. This value is C sub = C max sub max (C defined by the precision of the computer) when the matrix is perfectly well conditioned.

Laporte, M.↗

Numerical computation of transonic flows by finite-element and finite-difference methods

Studies on applications of the finite element approach to transonic flow calculations are reported. Different discretization techniques of the differential equations and boundary conditions are compared. Finite element analogs of Murman's mixed type finite difference operators for small disturbance formulations were constructed and the time dependent approach (using finite differences in time and finite elements in space) was examined.

Hafez, M. M.↗

Electron beam charging and ARC discharging of spacecraft insulating materials

The properties of the arc discharges which are caused by the laboratory exposure of dielectric materials to electron beams are examined, the intent being to simulate conditions on synchronous-orbit spacecraft. Extensive experimental studies are reported for planar dielectrics (Teflon, Kapton, Mylar) on the subjects of incident-flux scaling of discharge properties and the effects of high-energy broad-spectrum electron irradiation from a radioisotpe source. In addition a preliminary evaluation is made of the discharge susceptibility of fiber optic waveguides.

Balmain, K. G.↗

Impingement of Water Droplets on NACA 65A004 Airfoil at 8 deg Angle of Attack

The trajectories of droplets in the air flowing past an NACA 65AO04 airfoil at an angle of attack of 8 deg were determined.. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and presented to cover a large range of flight and atmospheric conditions. These impingement characteristics are compared briefly with those previously reported for the same airfoil at an angle of attack of 4 deg.

Brun, R. J.↗

Impingement of Water Droplets on NACA 65A004 Airfoil at 0 Deg Angle of Attack

The trajectories of water droplets in the air flowing past an NACA 6511004 airfoil at a n angle of attack of 0 deg were determined. The amount of water in droplet form impinging on the airfoil , the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and presented t o cover a large range of flight and atmospheric conditions. These impingement characteristics are compared briefly with those previously reported for the same airfoil at angles of attack of 4 deg and 8 deg.

Brun, Rinaldo J.↗

A laboratory study of the perceived benefit of additional noise attenuation by houses

Two Experiments were conducted to investigate the perceived benefit of additional house attenuation against aircraft flyover noise. First, subjects made annoyance judgments in a simulated living room while an operative window with real and dummy storm windows was manipulated in full view of those subjects. Second, subjects made annoyance judgments in an anechoic audiometric test chamber of frequency shaped noise signals having spectra closely matched to those of the aircraft flyover noises reproduced in the first experiment. These stimuli represented the aircraft flyover noises in levels and spectra but without the situational and visual cues present in the simulated living room. Perceptual constancy theory implies that annoyance tends to remain constant despite reductions in noise level caused by additional attenuation of which the subjects are fully aware. This theory was supported when account was taken for a reported annoyance overestimation for certain spectra and for a simulated condition cue overreaction.

Flindell, I. H.↗

Laboratory studies of the condensation and properties of amorphous silicate smokes

The results of experiments intended for defining the vapor phase condensation of refractory materials are reported, and the usefulness of applying laboratory data to astrophysical conditions is assessed. The testing apparatus used produced Mg-SiO smokes by boiling powders in an evaporator. Critical temperatures for the onset of nucleation were measured for SiO-H2 and Mg-SiO-H2 systems. Spectroscopic examination of the grains produced were determined to be similar to the spectra obtained from both carbonaceous chondrites and several stratospheric micrometeorites. The experiments demonstrated that direct nucleation of refractory silicates from the vapor phase yielded amorphous, metastable particles, resembling more circumstellar grains than a chondritic matrix. It is suggested that the formation of SiO(x) may control nucleation in oxygen-rich stars.

Nuth, J. A.↗

LANDSAT instruments characterization

Work performed for the LANDSAT instrument characterization task in the areas of absolute radiometry, coherent noise analysis, and between-date smoothing is reported. Absolute radiometric calibration for LANDSAT-5 TM under ambient conditions was performed. The TM Radiometric Algorithms and Performance Program (TRAPP) was modified to create optional midscan data files and to match the TM Image Processing System (TIPS) algorithm for pulse determination. Several data reduction programs were developed, including a linear regression and its plotted result. A fast Fourier transformation study was conducted on the resequenced TM data. Subscenes of homogeneous water within scenes over Pensacola, Florida were used for testing the FFT on the resequenced data. Finally, a gain and pulse height stability study of LANDSAT 5 TM spectral bands was performed.

Lee, Y.↗

A study of the relationship among wind speed, sea state, and the drag coefficient for a developing wave field

Controlled laboratory experiments are reported which demonstrate directly and quantitatively the influence of wave conditions in determining the drag law at the air-sea interface under neutral stability conditions. It is concluded that the analytic form first proposed by Kitaigorodskii (1970) models the roughness scale very well when the sea is dominated by the locally generated waves. It is demonstrated that, by using a unified two-parameter wave spectral model by Huang et al. (1981), Kitaigorodskii's result can be shown to contain the formulas of Charnock (1955) and Hsu (1974) as special cases. The results also identify two wind and wave-related parameters as important in determining the drag coefficient for developing wave fields.

Huang, N. E.↗

Multi-input multi-output system control for experimental aircraft

Results from the synthesis of control laws for an advanced short takeoff aircraft in a low-speed approach flight condition are given. Two of four candidate synthesis techniques are reported: direct eigenspace assignment and explicit model following via a linear quadratic regulator (LQR) formulation. A fundamental objective of this work is to obtain low-order feedback compensators, synthesized via the above techniques, and the judicious use of state estimation, thus allowing the use of a reasonable number of sensors for feedback.

Schmidt, David K.↗