Gas Wall Layer Experiments for SNS Target

2019 ◽  
Author(s):  
Justin R. Weinmeister ◽  
Elvis E. Dominguez-Ontiveros ◽  
Charlotte N. Barbier
Keyword(s):  
Cavitation Erosion ◽  
National Laboratory ◽  
Gas Injection ◽  
Wall Layer ◽  
Test Facility ◽  
Beam Power ◽  
Shear Stresses ◽  
Oak Ridge ◽  
Area Of Interest ◽  
Erosion Mitigation

Abstract The Proton Power Upgrade (PPU) project will increase the proton beam power at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), requiring new cavitation erosion mitigation techniques for the mercury target vessel. More precisely, a gas wall layer will be injected on the wall surface where heavy cavitation erosion is observed. In this paper, a series of experiments were performed to develop a gas layer on a simplified target geometry. First, experiments in water were used to test a prototype injection strategy in a simplified target nose geometry. Then the experiment was repeated at the Target Test Facility (TTF) at ORNL where mercury wass flowed in the same geometry. Observations showed that gas injection into liquid metal was much more sensitive to flow velocity than in water. Ultimately, the experiments showed the gas injection must be located very close to the area of interest in a non-intrusive configuration to reduce shear stresses in the flow for good gas coverage. This technique will be next implemented in a more prototypical target.

scholarly journals Conceptual Design of a MEDE Treatment System for Sodium Bonded Fuel

2008 ◽  
Author(s):  
Carl E. Baily ◽  
Karen A. Moore ◽  
Collin J. Knight ◽  
Peter B. Wells ◽  
Paul J. Petersen ◽  
...  
Keyword(s):  
Spent Nuclear Fuel ◽  
National Laboratory ◽  
Department Of Energy ◽  
Test Facility ◽  
Evaporation Chamber ◽  
Oak Ridge ◽  
Uranium Fuel ◽  
Fuel Assemblies ◽  
Metal Fuel ◽  
Enriched Uranium

Unirradiated sodium bonded metal fuel and casting scrap material containing highly enriched uranium (HEU) is stored at the Materials and Fuels Complex (MFC) on the Idaho National Laboratory (INL). This material, which includes intact fuel assemblies and elements from the Fast Flux Test Facility (FFTF) and Experimental Breeder Reactor-II (EBR-II) reactors, as well as scrap material from the casting of these fuels, has no current use under the terminated reactor programs for both facilities. The Department of Energy (DOE), under the Sodium-Bonded Spent Nuclear Fuel Treatment Record of Decision (ROD), has determined that this material could be prepared and transferred to an off-site facility for processing and eventual fabrication of fuel for commercial nuclear reactors. A plan is being developed to prepare, package, and transfer this material to the DOE HEU Disposition Program Office (HDPO), located at the Y-12 National Security Complex in Oak Ridge, Tennessee. Disposition of the sodium bonded material will require separating the elemental sodium from the metallic uranium fuel. A sodium distillation process known as MEDE (Melt-Drain-Evaporate), will be used for the separation process. The casting scrap material needs to be sorted to remove any foreign material or fines that are not acceptable to the HDPO program. Once all elements have been cut and loaded into baskets, they are then loaded into an evaporation chamber as the first step in the MEDE process. The chamber will be sealed and the pressure reduced to approximately 200 mtorr. The chamber will then be heated as high as 650 °C, causing the sodium to melt and then vaporize. The vapor phase sodium will be driven into an outlet line where it is condensed and drained into a receiver vessel. Once the evaporation operation is complete, the system is de-energized and returned to atmospheric pressure. This paper describes the MEDE process as well as a general overview of the furnace systems, as necessary, to complete the MEDE process.

Creep Strength and Microstructure of AL20-25+Nb Alloy Sheets and Foils for Advanced Microturbine Recuperators

2006 ◽  
Author(s):  
Philip J. Maziasz ◽  
John P. Shingledecker ◽  
Neal D. Evans ◽  
Yukinori Yamamoto ◽  
Karren L. More ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Creep Resistance ◽  
National Laboratory ◽  
Rupture Life ◽  
Cost Effective ◽  
Test Facility ◽  
Oak Ridge ◽  
Collaborative Program ◽  
Wide Range

The Oak Ridge National Laboratory (ORNL) and ATI Allegheny-Ludlum began a collaborative program in 2004 to produce a wide range of commercial sheets and foils of the new AL20-25+Nb stainless alloy, specifically designed for advanced microturbine recuperator applications. There is a need for cost-effective sheets/foils with more performance and reliability at 650–750°C than 347 stainless steel, particularly for larger 200–250 kW microturbines. Phase I of this collaborative program produced the sheets and foils needed for manufacturing brazed plated-fin (BPF) aircells, while Phase II provided foils for primary surface (PS) aircells, and modified processing to change the microstructure of sheets and foils for improved creep-resistance. Phase I sheets and foils of AL20-25+Nb have much more creep-resistance than 347 steel at 700–750°C, and foils are slightly stronger than HR120 and HR230. Preliminary results for Phase II show nearly double the creep-rupture life of sheets at 750°C/100 MPa, with the first foils tested approaching the creep resistance of alloy 625 foils. AL20-25+Nb alloy foils are also now being tested in the ORNL Recuperator Test Facility.

scholarly journals The use of acoustic inversion to estimate the bubble size distribution in pipelines

2012 ◽  
Vol 468 (2145) ◽  
pp. 2461-2484 ◽  
Author(s):  
Timothy G. Leighton ◽  
Kyungmin Baik ◽  
Jian Jiang
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
National Laboratory ◽  
Free Field ◽  
Travelling Wave ◽  
Bubble Size Distribution ◽  
Optical Measurements ◽  
Test Facility ◽  
Oak Ridge ◽  
Acoustic Inversion

The most popular technique for estimating the gas bubble size distribution (BSD) in liquids is through the inversion of measured attenuation and/or sound speed of a travelling wave. The model inherent in such inversions never exactly matches the conditions of the measurement, and the size of the resulting error (which could well be small in quasi-free field conditions) cannot be quantified if only a free field code exists. Users may be unaware of errors because, with sufficient regularization, such inversions can always be made to produce an answer, the accuracy of which is unknown unless independent (e.g. optical) measurements are made. This study was commissioned to assess the size of this error for the mercury-filled steel pipelines of the target test facility (TTF) of the spallation neutron source at Oak Ridge National Laboratory, TN, USA. Large errors in estimating the BSD (greater than 1000% overcounts/undercounts) are predicted. A new inversion technique appropriate for pipelines such as TTF gives good BSD estimations if the frequency range is sufficiently broad. However, it also shows that implementation of the planned reduction in frequency bandwidth for the TTF bubble sensor would make even this inversion insufficient to obtain an accurate BSD in TTF.

Numerical and Experimental Investigation of the Flow in the SNS Jet Flow Target

2015 ◽  
Author(s):  
Charlotte Barbier ◽  
Mark Wendel ◽  
David Felde ◽  
Michael C. Daugherty
Keyword(s):  
Numerical Simulations ◽  
Radiation Transport ◽  
Fluid Dynamic ◽  
National Laboratory ◽  
Jet Flow ◽  
Numerical Approach ◽  
General Purpose ◽  
Temperature Fields ◽  
Beam Power ◽  
Oak Ridge

Computational Fluid Dynamic (CFD) numerical simulations were performed for the flow inside the Spallation Neutron Source jet-flow target vessel at Oak Ridge National Laboratory. Different flow rates and beam conditions were tested to cover all the functioning range of the target, but for brevity, only the nominal case with a mass flow rate of 185 kg/s and a beam power of 1.54MW is presented here. The heat deposition rate from the proton beam was computed using the general-purpose Monte Carlo radiation transport code MCNPX and the commercial CFD code ANSYS-CFX was used to determine the flow velocity in the mercury and the temperature fields in both the mercury and the stainless steel vessel. Boundary conditions, turbulence model and mesh effects are presented in depth. To validate the numerical approach, Particle Imagery Velocimetry (PIV) measurements on a water-loop setup with an acrylic jet-flow target mock-up were performed and compared to the numerical simulations. It was found that a sustained wall jet was developed across the whole length of the vulnerable surface, confirming the good design of the jet-flow target. Overall, good agreements were observed between the experiments and the simulations: the velocity contours and the shape of the recirculation zone near the side baffle are qualitatively similar. However, some differences were also observed that underlines the shortcomings of both the numerical simulations and the experimental measurements.

Uncertainty Quantification of the RELAP5 Interfacial Friction Model in the Rod Bundle Geometry

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Ikuo Kinoshita ◽  
Toshihide Torige ◽  
Minoru Yamada
Keyword(s):  
Model Uncertainty ◽  
National Laboratory ◽  
Friction Model ◽  
Numerical Analyses ◽  
Test Facility ◽  
Interfacial Friction ◽  
Oak Ridge ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Rod Bundle

Interfacial friction in the core affects the two-phase mixture level and the distribution of the dispersed gas phase during a small-break loss-of-coolant accident (LOCA). The RELAP5/MOD3.2 code uses the drift flux model to describe the interfacial friction force in vertical dispersed flow, and the Chexal–Lellouche drift flux correlation is used for the rod bundle geometry. In the present study, the RELAP5 model uncertainty was quantified for the bubbly–slug interfacial friction model in the rod bundle geometry by conducting numerical analyses of void profile tests in the Thermal Hydraulic Test Facility (THTF) of the Oak Ridge National Laboratory (ORNL). The model uncertainty parameter was defined as a multiplier for the interfacial friction coefficient. Numerical analyses were performed by adjusting the multiplier so that the predicted void fractions agreed with the measured test data. The resultant distribution of the multipliers represented the interfacial friction model uncertainty.

Oxidation Behavior of Prospective Silicon Nitride Materials for Advanced Microturbine Applications

2001 ◽  
Author(s):  
Bjoern Schenk ◽  
Tom Strangman ◽  
Elizabeth J. Opila ◽  
R. Craig Robinson ◽  
Dennis S. Fox ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Elevated Temperatures ◽  
National Laboratory ◽  
Test Facility ◽  
Environmental Barrier ◽  
Oak Ridge ◽  
Oxidation Test ◽  
Environmental Barrier Coating ◽  
Barrier Coating ◽  
Engine Testing

Various laboratory tests have shown that high-pressure water vapor environments combined with elevated temperatures and intermediate gas velocities (current facilities limited to about 50 m/s) can cause grain boundary degradation and material recession in silica formers. Recent tests include burner rig testing conducted by NASA [1], Honeywell Engines & Systems [2], Siemens Power Generation [3], CRIEPI in Japan [4, 5], “Keiser rig” testing at Oak Ridge National Laboratory (ORNL) [6], and engine testing in the Allison 501K industrial gas turbine [7]. This paper presents a summary of oxidation test data of candidate silicon nitride materials for advanced microturbine applications. These data are of interest to microturbine component designers in order to determine the limits of safe unprotected component operation with respect to the given turbine environment, as well as to understand the behavior of ceramic microturbine components once local spallation of the protective environmental barrier coating has occurred. This paper intends to give materials and engine development engineers some guidance with respect to the different test facility capabilities and the prevailing oxidation/recession mechanisms to better understand/interprete the oxidation test results when developing new ceramic material compositions and environmental barrier coating systems.

Creep Strength and Microstructure of AL20-25+Nb Alloy Sheets and Foils for Advanced Microturbine Recuperators

2006 ◽  
Vol 129 (3) ◽  
pp. 798-805 ◽  
Author(s):  
P. J. Maziasz ◽  
J. P. Shingledecker ◽  
N. D. Evans ◽  
Y. Yamamoto ◽  
K. L. More ◽  
...  
Keyword(s):  
Creep Resistance ◽  
Phase 1 ◽  
National Laboratory ◽  
Rupture Life ◽  
Test Facility ◽  
Phase 2 ◽  
Oak Ridge ◽  
Collaborative Program ◽  
Wide Range ◽  
Air Cells

The Oak Ridge National Laboratory (ORNL) and ATI Allegheny Ludlum worked together on a collaborative program for about two years to produce a wide range of commercial sheets and foils of the new AL20-25+Nb™ (AL20–25+Nb) stainless alloy for advanced microturbine recuperator applications. There is a need for cost-effective sheets/foils with more performance and reliability at 650–750°C than 347 stainless steel, particularly for larger 200–250 kW microturbines. Phase 1 of this collaborative program produced the sheets and foils needed for manufacturing brazed plated-fin air cells, while Phase 2 provided foils for primary surface air cells, and did experiments on modified processing designed to change the microstructure of sheets and foils for improved creep-resistance. Phase 1 sheets and foils of AL20-25+Nb have much more creep-resistance than 347 steel at 700–750°C, and those foils are slightly stronger than HR120 and HR230. Results for Phase 2 showed nearly double the creep-rupture life of sheets at 750°C/100 MPa, and similar improvements in foils. Creep data show that Phase 2 foils of AL20-25+Nb alloy have creep resistance approaching that of alloy 625 foils. Testing at about 750°C in flowing turbine exhaust gas for 500 h in the ORNL Recuperator Test Facility shows that foils of AL20–25+Nb alloy have oxidation-resistance similar to HR120 alloy, and much better than 347 steel.

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