Automated detection of corrosion in used nuclear fuel dry storage canisters using residual neural networks
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73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
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Results for “Drying”
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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Enhancing Ce x Zr 1– x O 2 Activity for Methane Dry Reforming Using Subsurface Ni Dopants
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Identification of Highly Selective Surface Pathways for Methane Dry Reforming Using Mechanochemical Synthesis of Pd–CeO 2
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36 MATERIALS SCIENCE↗
Microstructural and Sensitivity Changes of Neat, Spray-Dried RDX
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Note: Optimization of the numerical data analysis for conductivity percolation studies of drying moist porous systems
A simplified data analysis protocol, for dielectric spectroscopy use to study conductivity percolation in dehydrating granular media is discussed. To enhance visibility of the protonic conductivity contribution to the dielectric loss spectrum, detrimental effects of either low-frequency dielectric relaxation or electrode polarization are removed. Use of the directly measurable monofrequency dielectric loss factor rather than estimated DC conductivity to parameterize the percolation transition substantially reduces the analysis work and time.
36 MATERIALS SCIENCE↗
Optimized spray drying process for preparation of one-step calcium-alginate gel microspheres
Calcium-alginate micro particles have been used extensively in drug delivery systems. Therefore we establish a one-step method for preparation of internally gelated micro particles with spherical shape and narrow size distribution. We use four types of alginate with different G/M ratio and molar weight. The size of the particles is measured using light diffraction and scanning electron microscopy. Measurements showed that with this method, micro particles with size distribution around 4 micrometers can be prepared, and SEM imaging showed that those particles are spherical in shape.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Dry cooler contribution to LCOE in a sCO 2 power cycle for CSP
In order to maintain viability as a future power-generating technology, concentrating solar power (CSP) must reduce its levelized cost of electricity (LCOE). One component of solving this problem is reducing the cost of the power block while simultaneously increasing the efficiency of the thermodynamic cycle. One disruptive technology that has the promise to accomplish this is supercritical CO 2 (sCO 2 ) based power cycles. Here, these cycles are conceptually similar to steam cycles; however, they have substantially smaller turbomachinery at equivalent power while also delivering more efficiency at turbine inlet temperatures of 500-700 °C.
14 SOLAR ENERGY↗
Fluctuations and power-law scaling of dry, frictionless granular rheology near the hard-particle limit
Here the flow of frictionless granular particles is studied with stress-controlled discrete element modeling simulations for systems varying in size from 300 to 100,000 particles. The volume fraction and shear-stress ratio μ are relatively insensitive to system size for a wide range of inertial numbers I. Second-order effects in strain rate, such as normal stress differences, require large system sizes to accurately extract meaningful results, notably a nonmonotonic dependence in the first normal stress difference with strain rate. The rheological response represented by the μ(I) scalar model works well at describing the lower-order aspects of the rheology, except near the quasistatic limit of these stress-controlled flows. The pressure is varied over five decades, and a pressure dependence of the coordination number is observed, which is not captured by the inertial number. Large fluctuations observed for small systems N≤1000 near the quasistatic limit can lead to the arrest of flow resulting in challenges to fitting the data to rheological relationships. The inertial number is also insufficient for capturing the pressure-dependent behavior of property fluctuations. Fluctuations in the flow and microstructural properties are measured in both the quasistatic and inertial regimes, including shear stress, pressure, strain rate, normal stress differences, volume fraction, coordination number, and contact fabric anisotropy. The fluctuations in flow properties scale self-similarly with pressure and system size. A transition in the scaling of fluctuations of stress properties and contact fabric anisotropy are measured and proposed as a quantitative identification of the transition from inertial to quasistatic flow.
36 MATERIALS SCIENCE↗
Optical analysis of nanoparticle packing after drying in microdroplets
The optical spectra of nanostructured patterns with different degrees of order, obtained by dehydration self-assembly of nanoparticles in solution microdroplets placed on a planar substrate, have been analyzed. The reflectance spectrum of the best-ordered pattern contains a characteristic peak, the position of which is determined by the average lattice period in the layer. It is shown that the height of this peak depends on the degree of order of the pattern structure. Patterns with different degrees of order have been simulated using a software for modeling the self-assembly process, which takes into account the properties of particles, substrate, and solvent, as well as the contact line dynamics during solvent evaporation. A peak occurs in the reflectance spectrum due to the resonance Rayleigh scattering in the ordered layer. The described technique for optical diagnostics can be used to analyze the degree of particle order in a pattern.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Hydride effects on discharged fuel clad related to accident conditions during dry storage and handling - 2016-0043
Safe handling of nuclear reactor discharged fuel requires an understanding of how the fuel (cladding) will perform under the various encountered conditions, including off-normal events, such as drop events in handling the storage canister. Clad failures under two distinct loading modes are considered: a diametrical pinch mode and an axial-bend mode. The mechanical response to the pinch mode and the bend mode loading are evaluated with ring compression testing (RCT) and three-point bend (TPB) testing, respectively. ZIRLO{sup R} clad samples were hydrogen charged to levels from 100 ppm to 800 ppm and then subjected to a hydride reorientation treatment involving heating to 400 deg. C and cooling while under hoop stresses ranging from 90 MPa to 170 MPa. Radial hydride reorientations were characterized and RCT and TPB tests were performed over a temperature range of ambient to 200 deg. C. Ductile-to-brittle transition temperatures (DBTT) were determined. Using finite element analysis (FEA), true stresses and strains are calculated and comparisons made between the RCT and TPB test modes. Because of the anisotropic properties of the clad and the relative orientation and generic effects of the hydrides, the DBTT was observed to be strongly dependent on the mode of strain application such that a DBTT associated with an RCT test is different from a DBTT obtained using an axial-bend test. Although the degree of radial hydriding strongly affected the pinch-mode RCT test, the same radial hydride impact was not observed for the axial-bend TPB test, which was affected strongly by the bulk hydride levels and not by the fraction of radial hydrides. (authors)
36 MATERIALS SCIENCE↗
Is spent nuclear fuel immune from delayed hydride cracking during dry storage? An IAEA coordinated research project - 2016-0048
Delayed hydride cracking (DHC) has been responsible for cracking in zirconium alloy pressure tubes and fuel cladding and is a concern for spent fuel storage. For cracking to start, sufficient hydrogen must be present for hydride to form at a flaw tip and the local tensile stress must be sufficiently large to crack the hydride (a crack will not extend if the threshold in the stress intensity factor, K{sub IH}, is not exceeded. A high-temperature limit exists when the yield stress of the cladding alloy becomes too low to crack the hydride. In this paper we describe measurements of K{sub IH} and the crack growth rate, V, in unirradiated Zircaloy-4 fuel cladding containing approximately 130 ppm hydrogen in the cold-worked stress-relieved condition representing pressurized water reactors (PWRs) and pressurized heavy-water (PHWR) reactors. Four methods are used to evaluate K{sub IH}. The test specimen and fixture used in these methods was the pin-loading tension configuration. The test temperature ranged from 227 to 315 deg. C. The mean value of K{sub IH} below 280 deg. C had little temperature dependence; it was about 5.5 MPa√m in the PWR cladding and slightly higher at 7 MPa√m in the PHWR material. At higher test temperatures, K{sub IH} increased dramatically to more than 12 MPa√m, whereas the crack growth rate declined toward zero. This behavior suggests that unirradiated Zircaloy-4 fuel cladding is immune from DHC above about 320 deg. C; this temperature may be increased to 360 deg. C by irradiation. The implications for spent fuel storage are that during early storage when the temperatures are high, any flaw will not extend by DHC, whereas at low temperatures, after many years of storage, flaws would have to be very large, approaching through wall, before being extended by DHC. To date, spent nuclear fuel is not known to have failed by DHC during storage, confirming the inference. (authors)
36 MATERIALS SCIENCE↗
Retrofitting Air Conditioning and Duct Systems in Hot, Dry Climates
This technical report describes CARB's work with Clark County Community Resources Division in Las Vegas, Nevada, to optimize procedures for upgrading cooling systems on existing homes in the area to implement health, safety, and energy improvements. Detailed monitoring of five AC systems showed that three of the five systems met or exceeded air flow rate goals.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Retrofitting Air Conditioning and Duct Systems in Hot, Dry Climates
This technical report describes CARB's work with Clark County Community Resources Division in Las Vegas, Nevada, to optimize procedures for upgrading cooling systems on existing homes in the area to implement health, safety, and energy improvements. Detailed monitoring of five AC systems showed that three of the five systems met or exceeded air flow rate goals.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Validation Experiments for Spent-Fuel Dry-Cask In-Basket Convection
This work consisted of the following major efforts; 1. Literature survey on validation of external natural convection; 2. Design the experiment; 3. Build the experiment; 4. Run the experiment; 5. Collect results; 6. Disseminate results; and 7. Perform a CFD validation study using the results. We note that while all tasks are complete, some deviations from the original plan were made. Specifically, geometrical changes in the parameter space were skipped in favor of flow condition changes, which were found to be much more practical to implement. Changing the geometry required new as-built measurements, which proved extremely costly and impractical given the time and funds available
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Source Physics Experiment Phase II Dry Alluvium Geology (DAG) Experiments Design Reviews
No abstract provided.
58 GEOSCIENCES↗
Summer Indoor Heat Pump Water Heater Evaluation in a Hot-Dry Climate
Heat pump water heaters offer a significant opportunity to improve water heating performance for the over 40% of U.S. households that heat domestic hot water using electric resistance storage water heaters. Numerous field studies have also been completed documenting performance in a variety of climates and applications. More recent evaluation efforts have focused attention on the performance of May through September 2014, with ongoing winter monitoring being sponsored by California utility partners. Summer results show favorable system performance with extrapolated annual water heating savings of 1,466 to 2,300 kWh per year, based on the observed hot water loads. Additional summer space cooling benefits savings of 121 to 135 kWh per year were projected, further increasing the water energy savings.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Summer Indoor Heat Pump Water Heater Evaluation in a Hot-Dry Climate
Heat pump water heaters offer a significant opportunity to improve water heating performance for the over 40% of U.S. households that heat domestic hot water using electric resistance storage water heaters. Numerous field studies have also been completed documenting performance in a variety of climates and applications. More recent evaluation efforts have focused attention on the performance of May through September 2014, with ongoing winter monitoring being sponsored by California utility partners. Summer results show favorable system performance with extrapolated annual water heating savings of 1,466 to 2,300 kWh per year, based on the observed hot water loads. Additional summer space cooling benefits savings of 121 to 135 kWh per year were projected, further increasing the water energy savings.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Seismic DAS observations of a large underground chemical explosion in dry tuff
On 18 October 2023 a 16.3-ton TNT equivalent chemical explosion was detonated underground at the Nevada National Security Site, generating a seismic event with a magnitude of 1.7 (Meyers et al., 2024). The associated seismic wavefield was measured on a Distributed Acoustic Sensing (DAS) array with slant range distances from 27 m – 1123 m. The first arriving phase traveled at an apparent velocity of about 2640 m s -1 from 27 m to 420 m slant range and about 2470 m s -1 from 505 m to 1123 m slant range according to the first arrival moveouts on the DAS data. The first arrival from the explosion temporarily saturated the cable from a slant range of 27 m – 186 m and 0.009 s to 0.084 s post detonation. From 186 m slant range to 420 m slant range, peak strain rates of 5.6 x 10 6 nm m -1 s -1 were observed for the first arrival phase. For the first arrival from 505 m slant range to 1123 m slant range, peak strain rates reduced to 8.0 x 104 nm m -1 s -1 . A comparison of the scaled accelerations computed from DAS, the geophone pairs, and the measurements of co-located accelerometer pairs show common agreement at the scaled ranges of the single point sensors. This study adds to the body of work reporting near-source DAS observations of the seismic wavefields generated by underground chemical explosions. These results indicate that near-source DAS observations can refine interpretations of phase identification from single-point sensor observations. Phase identification could be one mechanism that contributes scatter to single point seismic measurements which would confound the performance of empirical relationships for small explosions. Removing that mechanism may therefore reduce interstation variability and increase empirical relationship performance for small explosions.
58 GEOSCIENCES↗