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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Welding of Haynes 282 to Steels to Enable Modular Rotors for Advanced Ultra Super-Critical Steam Turbines

Steam turbines for an Advanced Ultra Super Critical (AUSC) fossil fired power plant will operate at temperatures well above those of current commercial steam cycles with inlet temperatures more than 760 C , which is beyond the capabilities of alloy steels presently used for steam turbine applications and requires advanced materials. Large components such as steam turbine rotors may be made of nickel based super alloys such as Haynes 282 (H282). However, monolithic forgings of superalloys in the sizes required for large steam turbines rotors can be prohibitively expensive besides many technical challenges. To minimize cost and alleviate the related technical challenges, superalloy use needs to be limited to locations on the steam turbine rotor where strength and temperature requirements cannot be met by conventional steels. This is possible if nickel-based superalloys can be successfully welded to steels and the related technical challenges - machining parts made of dissimilar welded materials, non-destructive examination of such welds for flaw detection; and, material properties of such hybrid components – are sufficiently addressed. In this technology development project, we successfully welded H282 to plates up to ~ 75 mm (~ 3 inches) to a 3.5NiCrMoV steel of similar thickness. Advanced ultrasonic inspection technique called Phased Array Ultrasonic Testing (PAUT) was employed to examine the dissimilar H282-Steel welds, into which flat bottomed side drilled holes (SDH) of various diameters were introduced, to determine the minimum detectable feature sizes; it was shown that with PAUT SDH of dia. down to 0.5 mm could be detected in the base alloys and SDH with dia. down to 2.4 mm could be detected in the weld metal under multiple orientations successfully. An autonomous machining process monitoring system was developed and demonstrated whereby the forces acting on the cutting tool could be actively monitored as the cutting tool transitioned from H282 to Steel across the weld using which the machining parameters can be potentially altered without interruption to extend tool life. This project successfully achieved its objectives of - i. Developing a welding methodology and viable welding geometries, to successfully join H282 to steel 3.5CrMoNiV steel to enable manufacture of modular steam turbine rotors for AUSC applications (conditions of at least 760 °Celsius and 3,100 psia (pounds per square inch absolute pressure) and evaluate the material properties of the welded specimen. ii. Employ the advanced ultrasonic inspection technique to the dissimilar weld metal joint and determine the minimum detectable feature sizes. iii. Develop effective machining techniques to machine such hybrid structures with online tool force monitoring and effect machine state metrics for optimal results.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2022

Meet the Lightslingers [Slides]

Electromagnetic applications such as Radar or telecommunications use decades-old technology: dipoles, dish/horn antennas, phased arrays.

42 ENGINEERING↗
DOE OSTI2020

A VIPA Spectrograph with Ultra-high Resolution and Wavelength Calibration for Astronomical Applications

A prototype spectrograph using a Virtually Imaged Phased Array (VIPA) as the main dispersion element is presented, and its performance is fully examined in our laboratory. The single-mode, fiber-fed spectrograph with simultaneous wavelength calibration possesses a spectral resolution well in excess of R≈1.12×10{sup 6} while the size of the VIPA is several orders of magnitude smaller than that of a conventional échelle with comparable resolution. In laboratory tests, the VIPA-based instrument with a homemade Yb:fiber ring laser frequency comb demonstrates a mode-to-mode tracking stability of 41 cm s{sup −1} over a period of 6 hr. The VIPA spectrograph has promising applications in various astronomical observations in which ultra-high resolution and calibration precision are imperative, such as solar physics research, exoplanet searching with the radial velocity method, and O{sub 2} detection in the atmosphere of Earth-like planets. Ultimately, feasible optimizations for night-sky observations under seeing limited conditions are discussed.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2010

PRELIMINARY ASSESSMENT OF NDE METHODS ON INSPECTION OF HDPE BUTT FUSION PIPING JOINTS FOR LACK OF FUSION WITH VALIDATION FROM MECHANICAL TESTING

Studies at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, are being conducted to evaluate nondestructive examinations (NDE) coupled with mechanical testing of butt fusion joints in high density polyethylene (HDPE) pipe for assessing lack of fusion. The work provides information to the United States Nuclear Regulatory Commission (NRC) on the effectiveness of volumetric inspection techniques of HDPE butt fusion joints in Section III, Division 1, Class 3, buried piping systems in nuclear power plants. This paper describes results from preliminary assessments using ultrasonic and microwave nondestructive techniques and mechanical testing with the high speed tensile impact test and the bend test for determining joint integrity. A series of butt joints were fabricated in 3408, 12 inch (30.5 cm) IPS DR-11 HDPE material by varying the fusion parameters to create good joints and joints containing a range of lack of fusion conditions. Six of these butt joints were volumetrically examined with time of flight diffraction (TOFD), phased array (PA) ultrasound, and the Evisive microwave system. The outer diameter (OD) weld beads were removed for microwave evaluation and the pipes ultrasonically re-evaluated. In two of the six pipes both the outer and inner diameter (ID) weld beads were removed and the pipe joints re-evaluated. Several of the pipes were sectioned and the joints destructively evaluated with the following techniques: high speed tensile test, bend test, and focused immersion ultrasound on a joint section removed from the pipe coupled with slicing through the joint and examining the revealed surfaces. The fusion parameters, nondestructive, and destructive evaluation results will be correlated to validate the effectiveness of what each NDE technology detects and what each does not detect. This is an initial limited study which will aid in identifying key future work.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2011

Nondestructive Evaluation of Nuclear-Grade Graphite

Nondestructive Evaluation of Nuclear Grade Graphite Dennis C. Kunerth and Timothy R. McJunkin Idaho National Laboratory Idaho Falls, ID, 83415 This paper discusses the nondestructive evaluation of nuclear grade graphite performed at the Idaho National Laboratory. Graphite is a composite material highly dependent on the base material and manufacturing methods. As a result, material variations are expected within individual billets as well billet to billet and lot to lot. Several methods of evaluating the material have been explored. Particular technologies each provide a subset of information about the material. This paper focuses on techniques that are applicable to in-service inspection of nuclear energy plant components. Eddy current examination of the available surfaces provides information on potential near surface structural defects and although limited, ultrasonics can be utilized in conventional volumetric inspection. Material condition (e.g. micro-cracking and porosity induced by radiation and stress) can be derived from backscatter or acousto-ultrasound (AU) methods. Novel approaches utilizing phased array ultrasonics have been attempted to expand the abilities of AU techniques. By combining variable placement of apertures, angle and depth of focus, the techniques provide the potential to obtain parameters at various depths in the material. Initial results of the study and possible procedures for application of the techniques are discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2010

Assessment of NDE Methods on Inspection of HDPE Butt Fusion Piping Joints for Lack of Fusion with Validation from Mechanical Testing

Studies at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, are being conducted to evaluate nondestructive examinations (NDE) coupled with mechanical testing of butt fusion joints in high-density polyethylene (HDPE) pipe for assessing lack of fusion. The work provides information to the U.S. Nuclear Regulatory Commission (NRC) on the effectiveness of volumetric inspection techniques of HDPE butt fusion joints in Section III, Division 1, Class 3, buried piping systems in nuclear power plants. This paper describes results from preliminary assessments using ultrasonic and microwave nondestructive techniques and mechanical testing with the high-speed tensile impact test and the side-bend test for determining joint integrity. A series of butt joints were fabricated in 3408, 12-in. IPS DR-11 HDPE material by varying the fusion parameters to create good joints and joints containing a range of lack-of-fusion conditions. Six of these butt joints were volumetrically examined with time-of-flight diffraction (TOFD), phased-array (PA) ultrasound, and the Evisive microwave system. The outer-diameter weld beads were removed for the microwave inspection. In two of the four pipes, both the outer and inner weld beads were removed and the pipe joints re-evaluated. The pipes were sectioned and the joints destructively evaluated with the side-bend test by cutting portions of the fusion joint into slices that were planed and bent. The last step in this limited study will be to correlate the fusion parameters, nondestructive, and destructive evaluation results to validate the effectiveness of what each NDE technology detects and what each does not detect. The results of the correlation will be used in identifying any future work that is needed.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2011

Assessment of NDE Methods to Detect Lack of Fusion in HDPE Butt Fusion Joints

Studies at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, were conducted to evaluate nondestructive examinations (NDE) coupled with mechanical testing of butt fusion joints in high-density polyethylene (HDPE) pipe for assessing lack of fusion. The work provided information to the United States Nuclear Regulatory Commission (NRC) on the effectiveness of volumetric inspection techniques of HDPE butt fusion joints in Section III, Division 1, Class 3, buried piping systems in nuclear power plants. This paper describes results from assessments using ultrasonic and microwave nondestructive techniques and mechanical testing with the high-speed tensile impact test and the side-bend test for determining joint integrity. A series of butt joints were fabricated in 3408, 12-inch (30.5-cm) IPS DR-11 HDPE material by varying the fusion parameters to create good joints and joints containing a range of lack-of-fusion conditions. Six of these butt joints were volumetrically examined with time-of-flight diffraction (TOFD), phased-array (PA) ultrasound, and the Evisive microwave system. The outer diameter (OD) weld beads were removed for microwave evaluation and the pipes ultrasonically re-evaluated. In two of the six pipes, both the outer and inner diameter (ID) weld beads were removed and the pipe joints re-evaluated. Some of the pipes were sectioned and the joints destructively evaluated with the high-speed tensile test and the side-bend test. The fusion parameters, nondestructive and destructive evaluation results have been correlated to validate the effectiveness of what each NDE technology detects and what each does not detect. There was no single NDE method that detected all of the lack-of-fusion flaws but a combination of NDE methods did detect most of the flaws.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2013

Ultrananocrystalline diamond films with optimized dielectric properties for advanced RF MEMS capacitive switches

An efficient deposition process is provided for fabricating reliable RF MEMS capacitive switches with multilayer ultrananocrystalline (UNCD) films for more rapid recovery, charging and discharging that is effective for more than a billion cycles of operation. Significantly, the deposition process is compatible for integration with CMOS electronics and thereby can provide monolithically integrated RF MEMS capacitive switches for use with CMOS electronic devices, such as for insertion into phase array antennas for radars and other RF communication systems.

36 MATERIALS SCIENCE↗
DOE OSTI2012

An Empirical Study on Ultrasonic Testing in Lieu of Radiography for Nuclear Power Plants

Research is being conducted for the U.S. Nuclear Regulatory Commission (NRC) at the Pacific Northwest National Laboratory (PNNL) to assess the capability, effectiveness, and reliability of ultrasonic testing (UT) as a replacement method for radiographic testing (RT) for inspecting nuclear power plant (NPP) components. A primary objective of this work is to evaluate UT techniques to assess their ability to detect, locate, size, and characterize fabrication flaws in typical NPP weldments. This particular study focused on the evaluation of four carbon steel pipe-to-pipe welds on specimens that ranged in thicknesses from 19.05 mm (0.75 in.) to 27.8 mm (1.094 in.) and were 355.6 mm (14.0 in.) or 406.4 mm (16.0 in.) in diameter. The pipe welds contained both implanted (intentional) fabrication flaws as well as bonus (unintentional) flaws throughout the entire thickness of the weld and the adjacent base material. The fabrication flaws were a combination of planar and volumetric flaw types, including incomplete fusion, incomplete penetration, cracks, porosity, and slag inclusions. The examinations were conducted using phased-array UT (PA UT) techniques applied primarily for detection and length sizing of the flaws. Radiographic examinations were also conducted on the specimens with RT detection and length sizing results being used to establish true state. This paper will discuss the comparison of UT and RT (true state) detection results conducted to date along with a discussion on the technical gaps that need to be addressed before these methods can be used interchangeably for repair and replacement activities for NPP components.

NDE reliability↗
DOE OSTI2012

Primary Water Stress Corrosion Cracks in Nickel Alloy Dissimilar Metal Welds: Detection and Sizing Using Established and Emerging Nondestructive Examination Techniques

The U.S. Nuclear Regulatory Commission has established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) as a follow-on to the international cooperative Program for the Inspection of Nickel Alloy Components (PINC). The goal of PINC was to evaluate the capabilities of various nondestructive evaluation (NDE) techniques to detect and characterize surface-breaking primary water stress corrosion cracks in dissimilar-metal welds (DMW) in bottom-mounted instrumentation (BMI) penetrations and small-bore (≈400-mm diameter) piping components. A series of international blind round-robin tests were conducted by commercial and university inspection teams. Results from these tests showed that a combination of conventional and phased-array ultrasound techniques provided the highest performance for flaw detection and depth sizing in dissimilar metal piping welds. The effective detection of flaws in BMIs by eddy current and ultrasound shows that it may be possible to reliably inspect these components in the field. The goal of PARENT is to continue the work begun in PINC and apply the lessons learned to a series of open and blind international round-robin tests that will be conducted on a new set of piping components including large-bore (≈900-mm diameter) DMWs, small-bore DMWs, and BMIs. Open round-robin testing will engage universities and industry worldwide to investigate the reliability of emerging NDE techniques to detect and accurately size flaws having a wide range of lengths, depths, orientations, and locations. Blind round-robin testing will invite testing organizations worldwide, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from easy to very difficult to detect and size. This paper presents highlights of PINC and reports on the plans and progress for PARENT round-robin tests.

cracks↗
DOE OSTI2018

On Success Probability of Eavesdropping Attack in 802.11ad mmWave WLAN

Next generation wireless communication networks utilizing 60 GHz millimeter wave (mmWave) frequency bands are expected to achieve multi-gigabit throughput with the use of highly directional phased-array antennas. These directional signal beams provide enhanced security to the legitimate networks due to the increased difficulties of eavesdropping. However, there still exists significant possibility of eavesdropping since (i) the reflections of the signal beam from ambient reflectors enables opportunistic stationary eavesdropping attacks; and (ii) carefully designed beam exploration strategy enables active nomadic eavesdropping attack. This paper discusses eavesdropper attack strategies for 802.11ad mmWave systems and provides the first analytical model to characterize the success possibility of eavesdropping in both opportunistic stationary attacks and active nomadic attacks.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2020

Overview of TAE technologies’ HHFW project on LAPD

Simulation survey performed at TAE Technologies, has demonstrated that high harmonic fast wave (HHFW) heating is a promising scenario to heat core electrons of FRC plasma. To prepare the proposed experimental study of HHFW antenna-plasma coupling and wave propagation on LAPD machine at UCLA, a high-power-capable 4-strap antenna has been calculated and designed through collaboration among TAE, ORNL, ASIPP, and UCLA. This antenna was mechanically designed and fabricated by ASIPP and it has been installed recently on LAPD. Meanwhile, by using the Petra-M code, a newly developed generic electromagnetic simulation tool for modeling RF wave propagation, the RF-SciDAC team starts 3D full wave simulations. Detailed information on antenna electromagnetic simulations and mechanical design, as well as preliminary experimental results of wave propagation study with the newly installed phased- array antenna, will be presented in this paper.REFE

Yang, Xiaokang↗
DOE OSTI2019

An Innovative Secure mmWave M2M Communication Network for Operating Drones

Analyze RF (Radio Frequency) coverage in the sky with the innovative use of mmWave phased arrays aimed towards the drone corridor to harness the power of 5G – multiplicative improvement in data throughput & reduction in latency, and support of massive M2M communications. Apply MA (Multiple Access) technology to increase the spectral efficiency by covering a swarm of drones with a single mmWave beam and associated radio resources. Design energy efficient low-bit quantization to form mmWave beams for drone operation. Use drones’ navigation capabilities to significantly improve security by e.g. evading attackers. Utilize intra-drone communication to improve reliability as well as security. Demonstrate the simulated recovery of a critical infrastructure such as a power grid that requires a black restart with mmWave modeling and experiments .

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2023

Sub-nanosecond RF synchronization for MIMO software defined radio sensor networks

This disclosure presents distributed and decentralized synchronization for wireless transceivers. The disclosed system, device, and method achieve sub-nanosecond synchronization using low-cost commercial off the shelf software defined radios. By providing a decentralized mechanism that does not rely on a hierarchical master-slave structure, networks constructed as disclosed are robust to sensor drop-out in contested or harsh environments. Such networks may be used to create phased array radars and communication systems without requiring wired connections to distribute a common clock or local oscillator reference.

Moghaddam, Mahta↗
DOE OSTI2016

Inspection Technology Advancements for Hanford Double Shell Tank Integrity Verification - 16150

The Hanford double-shell tanks (DSTs) were constructed in southeastern Washington State between 1968 and 1986 to store nuclear waste. Most of the tank waste came from the Hanford nuclear weapons program, which has been stopped for more than 25 years. The tanks will be needed for many years to come until suitable vitrification and permanent storage solutions are developed. These tanks are nominally 45 ft. deep from the dome peak to the floor. The inner tank is nominally 75 ft. dia. and the outer tank is nominally 80 ft. dia., leaving a 2.5 ft. annulus between the two side tank walls. The waste management program (under direction of Washington River Protection Solutions, WRPS) manages inspections of these DSTs from the annulus to justify their continued safe service and to avoid the high cost of new replacement tanks. Over time, the Hanford Tank Farm contractors, currently WRPS, have increased their ultrasound inspections of these tanks. Pacific Northwest National Laboratory has worked with the Hanford Tank Farm contractors for more than 15 years to advance applicable tank nondestructive inspection technology for improved performance and cost reduction. Past, present, and planned technology advancements are addressed in this paper, including tank wall ultrasonic testing examination, extreme value statistical analysis, phased array for the tank wall, transmit/receive tandem synthetic aperture focusing technique knuckle examination, and electromagnetic acoustic transducer screening of the tank wall including mill-scale compensation. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Progress on Advancing Robotic Ultrasonic Volumetric Inspection Technology for Hanford Under-tank Inspection - 19474

The Hanford River Protection Project is reliant on safe interim storage of high-level waste at the Hanford site and will continue to depend on it until the waste has been treated and vitrified by the Hanford Waste Treatment and Immobilization Plant (WTP). The Hanford double-shell tanks (DSTs) have provided interim storage since the DSTs were put into service (1971 - 1986) and the RPP will continue to rely on their service until least 2050, at which time the 27 in-service DSTs will be 14-54 years beyond their original design lives. As the DSTs continue to age and be operated beyond design life, reliable leak integrity assessments of primary tanks and secondary liners will become increasingly important in order to provide situational awareness to tank operations personnel and to support risk-informed decisions on the selection of DSTs as waste feed staging tanks and the order and timing of future DST refurbishment or, alternatively, DST retrieval sequence. This paper summarizes progress made in fiscal year (FY) 2018 on the engineering of a robotic air-slot volumetric inspection system (RAVIS) that is designed to perform ultrasonic (volumetric) leak integrity inspections of physically inaccessible primary tank bottom plates and welds. Leak integrity inspections performed with the RAVIS will supplement today's primary tank leak integrity inspections, which are currently limited to physically accessible sidewall plates and welds. The RAVIS will be deployed into air slots of the insulating concrete (refractory) pad beneath the primary tanks and use its ultrasonic guided wave phased-array (GWPA) sensor to electronically steer an ultrasonic beam 360-degrees around the sensor to volumetrically examine adjacent carbon steel plates and welds covered by refractory pad material. Deployments of RAVIS down multiple air-slots will be performed to determine which regions of a tank bottom have sound leak integrity or which regions are in need of future wall thickness restoration or weld repair due to pitting corrosion, general corrosion, or heat/stress-induced cracks. The initial RAVIS design and the flaw detection test results for the first air-slot GWPA sensor that was designed to fit inside the air-slots will be presented in this paper. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2011

Preparation N-F-codoped TiO{sub 2} nanorod array by liquid phase deposition as visible light photocatalyst

Research highlights: {yields} The formation of N, F-codoped TiO{sub 2} nanorod arrays via the LPD. {yields} Calcination temperature greatly effects the incorporation of N and F into TiO{sub 2}. {yields} TNRAs calcined at 450 {sup o}C showed highest visible light photocatalytic activity. {yields} A synergetic effect of 1D nanorod arrays and appropriate amount of N and F codoping. -- Abstract: An efficient method for the preparation of N-F-codoped visible light active TiO{sub 2} nanorod arrays is reported. In the process, simultaneous nitrogen and fluorine doped TiO{sub 2} nanorod arrays on the glass substrates were achieved by liquid phase deposition method using ZnO nanorod arrays as templates with different calcination temperature. The as-prepared samples were characterized by Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis absorption spectra measurements. It was found that calcination temperature is an important factor influencing the microstructure and the amount of N and F in TiO{sub 2} nanorod arrays samples. The visible light photocatalytic properties were investigated using methylene blue (MB) dye as a model system. The results showed that N-F-codoped TiO{sub 2} nanorod arrays sample calcined at 450 {sup o}C demonstrated the best visible light activity in all samples, much higher than that of TiO{sub 2} nanoparticles and P25 particles films.

36 MATERIALS SCIENCE↗