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At least 523 records · Page 29

Fatigue Test Design: Scenarios for Biaxial Fatigue Testing of a 60-Meter Wind Turbine Blade

Current practice in commercial certification of wind turbine blades is to perform separate flap and lead-lag fatigue tests. The National Renewable Energy Laboratory has been researching and evaluating biaxial fatigue testing techniques and demonstrating various options, typically on smaller-scale test articles at the National Wind Technology Center. This report evaluates some of these biaxial fatigue options in the context of application to a multimegawatt blade certification test program at the Wind Technology Testing Center in Charlestown, Massachusetts.

17 WIND ENERGY↗

Summary of ALSEP Test Loop Solvent Irradiation Testing

Separating the minor actinide elements (americium and curium) from the fission product lanthanides is an important step in closing the nuclear fuel cycle. Isolating the minor actinides will allow transmuting them to short lived or stable isotopes in fast reactors, thereby reducing the long-term hazard associated with these elements. The Actinide Lanthanide Separation Process (ALSEP) is being developed by the DOE-NE Material Recovery and Waste Form Development Campaign to accomplish this separation with a single process. To develop a fundamental understanding of the solvent degradation mechanisms for the ALSEP Process, testing was performed in the INL Radiolysis/Hydrolysis Test Loop for the extraction section of the ALSEP flowsheet. This work culminated in the completion of the level two milestone (M2FT-16IN030102021) "Complete ALSEP test loop solvent irradiation test.” This report summarizes the testing performed and the impact of radiation on the ALSEP Process performance as a function of dose.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

3013 Fire Test 2020: Post-Test Measurements and Analysis

Sandia National Laboratory conducted fire tests on ten 3013 containers with varying amounts of water. The containers with attached manifolds were sent to Los Alamos National Laboratory for post-test measurements of the plastic deformation, the amount of water remaining on the material post-test and the mass loss. The measurements of the plastic deformation were used to determine the free gas volume in each container and manifold post-test. The disassembly of each container was documented by photographs. The amount of pre-test gas constituents is also reported using data in the Sandia Final Report.

3013 fire test↗

Cryogenic testing of Planck sorption cooler test facility

A test facility has been upgraded in preparation for testing of two hydrogen sorption cryocoolers operating at 18/20 K. these sorption coolers are currently under development at the Jet Propulsion Laboratory. This work summarizes the scope of the test facility upgrade, including design for cryogenic cooling power delivery, system thermal management, insulation schemes, and data acquisition techniques. Ground support equipment for the sorption coolers, structural features of the test chamber, and the vacuum system involved for system testing will also be described in detail.

Planck sorption cooler↗

A Capable and Temporary Test Facility on a Shoestring Budget: The MSL Touchdown Test Facility

The Mars Science Laboratory mission (MSL) has undertaken a developmental Touchdown Test Program that utilizes a full-scale rover vehicle and an overhead winch system to replicate the skycrane landing event. Landing surfaces consisting of flat and sloped granular media, planar, rigid surfaces, and various combinations of rocks and slopes were studied. Information gathered from these tests was vital for validating the rover analytical model, validating certain design or system behavior assumptions, and for exploring events and phenomenon that are either very difficult or too costly to model in a credible way. This paper describes this test program, with a focus on the creation of test facility, daily test operations, and some of the challenges faced and lessons learned along the way.

rover↗

James Webb Space Telescope Core 2 Test - Cryogenic Thermal Balance Test of the Observatorys Core Area Thermal Control Hardware

The James Webb Space Telescope (JWST), successor to the Hubble Space Telescope, will be the largest astronomical telescope ever sent into space. To observe the very first light of the early universe, JWST requires a large deployed 6.5-meter primary mirror cryogenically cooled to less than 50 Kelvin. Three scientific instruments are further cooled via a large radiator system to less than 40 Kelvin. A fourth scientific instrument is cooled to less than 7 Kelvin using a combination pulse-tube Joule-Thomson mechanical cooler. Passive cryogenic cooling enables the large scale of the telescope which must be highly folded for launch on an Ariane 5 launch vehicle and deployed once on orbit during its journey to the second Earth-Sun Lagrange point. Passive cooling of the observatory is enabled by the deployment of a large tennis court sized five layer Sunshield combined with the use of a network of high efficiency radiators. A high purity aluminum heat strap system connects the three instrument's detector systems to the radiator systems to dissipate less than a single watt of parasitic and instrument dissipated heat. JWST's large scale features, while enabling passive cooling, also prevent the typical flight configuration fully-deployed thermal balance test that is the keystone of most space missions' thermal verification plans. This paper describes the JWST Core 2 Test, which is a cryogenic thermal balance test of a full size, high fidelity engineering model of the Observatory's 'Core' area thermal control hardware. The 'Core' area is the key mechanical and cryogenic interface area between all Observatory elements. The 'Core' area thermal control hardware allows for temperature transition of 300K to approximately 50 K by attenuating heat from the room temperature IEC (instrument electronics) and the Spacecraft Bus. Since the flight hardware is not available for test, the Core 2 test uses high fidelity and flight-like reproductions.

JWST Thermal Core 2 Test↗

Development and Testing of Pulse Guns for Combustion Instability Testing

Combustion stability requirements of a liquid propellant rocket engine are most commonly verified by evaluating the oscillatory pressure or vibration characteristics following an artificial disturbance of the combustion in the combustion chamber. Two types of devices are most commonly used for dynamic stability rating – nondirectional bombs and pulse guns. Bombs have historically been used most often, especially for the large engines developed around the Apollo era. However, bombs in recent years have become much more expensive and difficult to procure, and their transportation and handling requirements have become more demanding. Pulse guns, with inherently less expensive materials, and far less restrictive handling and shipping requirements, have become an attractive alternative. The NASA Marshall Space Flight Center has developed a pulse gun for use during future development programs at the center, and as a design reference for interested commercial users. The objective of this paper is to present the different variants of the pulse gun and characterize performance over a range of parameters. The parameters include the breech diameter and corresponding volume, barrel length, amount of gun powder used, the method of containing the gunpowder within the breech, and the pressure rating of the burst disk. In total, 44 tests were conducted with the pulse gun firing into a test chamber pressurized to 2300 psig with gaseous nitrogen. The best experimental results – including the highest and most consistent peak pressure amplitudes recorded by dynamic pressure sensors in the test chamber – were from a configuration consisting of a 0.40” inner-diameter breech, 15-16 grains of gunpowder wrapped in cigarette paper, and a 24,000 psid burst disk. With this configuration, the zero-to-peak overpressures recorded in the test chamber ranged from about 37% to 58% of the 2300 psig mean pressure, which is adequate for typical combustion stability rating. To complement the data analysis, the acoustics of the pressure waves as they propagated through the pulse gun and into the test chamber were modeled. A more comprehensive final report of this pulse gun development program is planned to be available in the near future.

Pulse Gun↗

Computational Fluid Dynamics Models of the NASA White Sands Test Facility Particle Impact Test Nozzles

The particle impact ignition mechanism is considered to be the most effective means for igniting metals in gaseous oxygen environments and is a concern for every oxygen system. For this reason, the National Aeronautics and Space Administration (NASA) commits a large amount of resources attempting to understand and defend against this phenomenon. The most practical means of accomplishing this is through extensive of testing. To this end, over the years NASA has developed and built a facility and various apparatuses to test material or component vulnerability to a particle impact ignition. In testing materials, NASA uses sub-sonic and supersonic nozzles to replicate the conditions that a material is expected to experience in service. However, challenges include obtaining an understanding of the gas dynamics and of the particle behavior through and up to the point of impact at the material under test. One means of addressing these challenges is the use of computational fluid dynamics (CFD). If a CFD model can be built and validated, the model can then be used to confidently interrogate changes to inlet conditions and particle geometries, as well as changes to nozzle geometries to better simulate a material’s in-situ conditions and greatly reduce or eliminate trial-and-error approaches in testing. This paper will show NASA’s approach to and results of using CFD to better understand their particle impact nozzles.

Computational Fluid Dynamics↗

The Fission Accelerated Steady State Test (FAST) -- A Revised Capsule Design for the Accelerated Testing of Advanced Reactor Fuels

In an effort to improve the development and testing of novel nuclear fuels, a detailed evaluation on reducing the size of fuel specimens for irradiation has been performed. Theoretically speaking, reducing the fuels diameter and incorporating an inner capsule while maintaining the original outside diameter of the experiment significantly reduces the experiment’s sensitivity to fabrication tolerances and drastically reduces the time necessary to reach a desired fuel burnup; both of which improve the cost and schedule associated with the fuel testing. Simulations of this reduced diameter, double encapsulated concept have been performed using Abaqus, MCNP, and ORIGEN. The results of the Abaqus simulations are beyond the scope of this summary and will not be presented herein. For results of these Abaqus simulations, see Beausoleil [2]. The models were tested using various parameters and design deviations which were then compared to the original Advanced Fuels Campaign (AFC) designs. The results of these simulations confirmed that the introduction of a second capsule coupled to a reduction in the fuel pin diameter significantly reduces the experiment’s sensitivity to fabrication tolerances and reduces the time to reach a desired burnup by nearly an order of magnitude. The original AFC design requires approximately 11.7 years to reach 30 Atom % Heavy Metal (at% HM) burnup. A burnup of 30 at% HM can be reached in approximately 2.5 to 3.5 years (irradiation position dependent) with a fuel diameter ½ (~0.097 in. diameter) that of the original AFC design. An added benefit to the fuel pin diameter reduction is that more specimens can be irradiated in any given cycle. Essentially, significantly more specimens can be tested and incur more burnup over a given operating cycle relative to the AFC design. This allows the development of a large test matrix of samples with rapid throughput in ATR.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Design of a Supercritical Carbon Dioxide Corrosion Test Rig for Tube-to-Tubesheet Joint and High Temperature Insulation Testing

Supercritical carbon dioxide (S-CO{sub 2}) Brayton cycles are attractive for thermal power generation since they offer highly efficient means of power generation (thermal solar, coal, nuclear, etc.) with a compact footprint, resulting in potential cost savings. The University of California, Berkeley (UCB) is developing an S-CO{sub 2}- Brayton Cycle design for advanced reactors using sodium and molten salt coolants. Coiled tube gas heaters (CTGH) made from 316L stainless steel are presently foreseen to transfer heat from a sodium or molten salt coolant at atmospheric pressure (approximately 0.1 MPa) to an S-CO{sub 2} power conversion fluid at very high pressure (approximately 20 MPa or more). CTGHs operate at temperatures of 400 to 700 deg. C where time-dependent creep is an important design issue. Given the high external pressure conditions and compressive stress, the highest stresses and creep rates in CTGH are expected to occur at the tube-to-tubesheet joints. UCB has developed different diffusion bonding techniques to fabricate 316L stainless steel tube-to-tubesheet joint dummies representative of the final design: press fitting and diffusion bonding, tube expansion and diffusion bonding as well as hybrid friction diffusion bonding. High pressure/temperature testing of such joints in an S-CO{sub 2} environment is important prior to deployment and will be foreseen with the corrosion test rig introduced in this work. This summary provides a brief overview of an Innovative S-CO, creep corrosion test rig for tube-to-tube sheet joint testing currently under construction at UCB. In contrast to other comparable test rigs, the design (1) makes the samples an active part of the pressure barrier and (2) uses internal insulation to reduce the temperature at the vessel wall, allowing the vessel to be manufactured from commercial carbon steel. (authors)

42 ENGINEERING↗

Detection of nuclear testing from surface concentration measurements: Analysis of radioxenon from the February 2013 underground test in North Korea

A method is outlined and tested to detect low level nuclear or chemical sources from time series of concentration measurements. The method uses a mesoscale atmospheric model to simulate the concentration signature from a known or suspected source at a receptor which is then regressed successively against segments of the measurement series to create time series of metrics that measure the goodness of fit between the signatures and the measurement segments. The method was applied to radioxenon data from the Comprehensive Test Ban Treaty (CTBT) collection site in Ussuriysk, Russia (RN58) after the Democratic People's Republic of Korea (North Korea) underground nuclear test on February 12, 2013 near Punggye. The metrics were found to be a good screening tool to locate data segments with a strong likelihood of origin from Punggye, especially when multiplied together to a determine the joint probability. Metrics from RN58 were also used to find the probability that activity measured in February and April of 2013 originated from the Feb 12 test. A detailed analysis of an RN58 data segment from April 3/4, 2013 was also carried out for a grid of source locations around Punggye and identified Punggye as the most likely point of origin. Thus, the results support the strong possibility that radioxenon was emitted from the test site at various times in April and was detected intermittently at RN58, depending on the wind direction. The method does not locate unsuspected sources, but instead, evaluates the probability of a source at a specified location. However, it can be extended to include a set of suspected sources. Extension of the method to higher resolution data sets, arbitrary sampling, and time-varying sources is discussed along with a path to evaluate uncertainty in the calculated probabilities.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

Monitoring of Wind Turbine Gearbox Condition through Oil and Wear Debris Analysis: A Full-Scale Testing Perspective

Despite the wind industry's dramatic development during the past decade, it is still challenged by premature turbine subsystem/component failures, especially for turbines rated above 1 MW. Because a crane is needed for each replacement, gearboxes have been a focal point for improvement in reliability and availability. Condition monitoring (CM) is a technique that can help improve these factors, leading to reduced turbine operation and maintenance costs and, subsequently, lower cost of energy for wind power. Although technical benefits of CM for the wind industry are normally recognized, there is a lack of published information on the advantages and limitations of each CM technique confirmed by objective data from full-scale tests. This article presents first-hand oil and wear debris analysis results obtained through tests that were based on full-scale wind turbine gearboxes rated at 750 kW. The tests were conducted at the 2.5-MW dynamometer test facility at the National Wind Technology Center at the National Renewable Energy Laboratory. The gearboxes were tested in three conditions: run-in, healthy, and damaged. The investigated CM techniques include real-time oil condition and wear debris monitoring, both inline and online sensors, and offline oil sample and wear debris analysis, both onsite and offsite laboratories. The reported results and observations help increase wind industry awareness of the benefits and limitations of oil and debris analysis technologies and highlight the challenges in these technologies and other tribological fields for the Society of Tribologists and Lubrication Engineers and other organizations to help address, leading to extended gearbox service life.

17 WIND ENERGY↗

Deep Borehole Field Test Laboratory and Borehole Testing Strategy

Deep Borehole Disposal (DBD) of high-level radioactive wastes has been considered an option for geological isolation for many years (Hess et al. 1957). Recent advances in drilling technology have decreased costs and increased reliability for large-diameter (i.e., ≥50 cm [19.7”]) boreholes to depths of several kilometers (Beswick 2008; Beswick et al. 2014). These advances have therefore also increased the feasibility of the DBD concept (Brady et al. 2009; Cornwall 2015), and the current field test design will demonstrate the DBD concept and these advances. The US Department of Energy (DOE) Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013) specifically recommended developing a research and development plan for DBD. DOE sought input or expression of interest from States, local communities, individuals, private groups, academia, or any other stakeholders willing to host a Deep Borehole Field Test (DBFT). The DBFT includes drilling two boreholes nominally 200m [656’] apart to approximately 5 km [16,400’] total depth, in a region where crystalline basement is expected to begin at less than 2 km depth [6,560’]. The characterization borehole (CB) is the smaller-diameter borehole (i.e., 21.6 cm [8.5”] diameter at total depth), and will be drilled first. The geologic, hydrogeologic, geochemical, geomechanical and thermal testing will take place in the CB. The field test borehole (FTB) is the larger-diameter borehole (i.e., 43.2 cm [17”] diameter at total depth). Surface handling and borehole emplacement of test package will be demonstrated using the FTB to evaluate engineering feasibility and safety of disposal operations (SNL 2016).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Initial Argonne Sodium Draining Tests: Analysis of Test Results and Comparison with Water Draining Behavior

Three initial sodium draining experiments have been carried out in which sodium was drained from a 0.46 m high 4.6 mm inner diameter vertical stainless steel tube wetted by the sodium representative of a sodium channel in a compact diffusion-bonded sodium-to-CO 2 heat exchanger. Prior to the startup of sodium testing, shakedown tests were conducted with water. In all three sodium experiments, the sodium drained efficiently from the channel. Sodium and water both drain efficiently from a 4.6 mm inner diameter vertical stainless steel tube. This is an important and good result for the design of compact diffusion-bonded heat exchanger sodium channels. Sodium drains more efficiently than water. This is also an important and good result for the design of compact diffusion-bonded heat exchanger sodium channels. The draining phenomena observed with sodium and water are significantly different. The draining of water involves an initial rapid slug draining phase followed by a linear rate draining phase followed by a slow draining phase involving draining of rivulets and drops. This behavior has previously been reported in the literature for viscous fluids. The draining of sodium involves an initial rapid slug draining phase but no discernable linear rate draining phase. There is a subsequent slow draining phase. However, unlike the slow draining phase with water that involves a number of rivulets and drops, the slow draining phase with sodium in two out of three sodium tests mainly involves a single discrete event in which a mass of sodium drains from the tube. This single discrete draining event encompasses most of the sodium mass remaining inside of the tube following the rapid slug draining phase. The existence of a single discrete draining event during the slow draining phase with sodium versus several rivulet and drop draining events with water is thought to simply reflect the fact that significantly lower mass fractions of liquid are left behind inside of the tube following the rapid slug draining phase with sodium relative to water. For the sodium tests, the progress of wetting of the stainless steel by sodium was monitored by means of the voltage drop across the tube outer diameter measured by pairs of opposing electrodes welded to the tube outer surface at three different elevations. The electrode data remarkably reveals phenomena during the sodium draining. The downward passage of the sodium slug trailing edge past each electrode was observed from which a mean slug trailing edge velocity could be determined. The subsequent slower increase in voltage drop suggests draining and thinning of a sodium film left behind upon the tube inner surface; wiggles in the voltage drop data are suggestive of the descent of waves on the film. It is thought that the draining sodium film collects as a mass likely near the lower end of the tube and detaches corresponding to the single discrete draining event observed in the load cell data. The minimum circular channel inner diameter for the draining of water and sodium without the formation of lenses that bridge the channel and may remain inside of the tube without draining is predicted with a correlation to be 2.2 mm. The highest priority for future sodium draining testing is to investigate other channel geometries such as a rectilinear channel or a semicircular channel.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Progress Report on Modified Burst Testing and Alternative Test Methodologies

Performance of accident-tolerant fuel candidates must be assessed during the pellet-cladding mechanical interaction (PCMI) phase of a design-basis reactivity-initiated accident (RIA). Therefore, in this report, we describe Fiscal Year (FY) 2019 research activities on the development of separate-effects testing for ATF cladding candidate iron-chromium-aluminum (FeCrAl) tube specimens under loading conditions comparable to the PCMI. The first section of this report provides modified-burst test (MBT) results of unirradiated FeCrAl tubes at various pressurization-rates and an RIA-relevant temperature (275°C). The failure strain of FeCrAl was observed and calculated using a high-speed digital-image correlation (DIC) technique developed recently under the Department of Energy (DOE)’s Advanced Fuel Campaign (AFC). To overcome the complexities of performing MBT in a hot-cell environment on irradiated samples, a “plane-strain tension” (PST) test was proposed as an alternative methodology for PCMI testing. The relevance of the PST test as an alternative to MBT for irradiated specimens was explicated using the data available in the literature. The design of hot-cell compatible PST fixtures and a specific holder for PST hot-cell specimen machining were developed.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Thermal Hydraulic Experimental Test Article - Report of THETA Commissioning for METL Testing

The Thermal Hydraulic Experimental Test Article (THETA) is a facility that will be used to develop sodium components and instrumentation as well as acquire experimental data for validation of reactor thermal hydraulic and safety analysis codes. The facility will simulate nominal conditions as well as protected/unprotected loss of flow accidents in a sodium-cooled fast reactor (SFR). High fidelity distributed temperature profiles of the developed flow field will be acquired with Rayleigh backscatter based optical fiber temperature sensors. The facility is being designed in partnership with systems code experts to tailor the experiment to ensure the most relevant and highest quality data for code validation. THETA is comprised of a traditional primary and secondary system. The primary system is submerged in the pool of sodium and consists of a pump, electrically heated core, intermediate heat exchanger, and connected piping and thermal barriers (redan). The secondary system, located outside of the sodium pool, consists of a pump, sodium to air heat exchanger, and connected piping and valves. Figure 1 illustrates the main components of the primary system. THETA has been installed in the Mechanisms Engineering Test Loop (METL) with the primary system in the 28 inch Test Vessel #4, Figure 2 and Figure 3. Since the FY20 THETA status report, [1], further water shakedown testing was performed, some final welding modifications were performed, all system components were sanitized, dry assembled, and commissioned before installing into METL test vessel #4. The THETA submersible electromagnetic flowmeter was welded closed to hermetically seal internal components from sodium followed by a helium leak check for the final time

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗