The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Kai Sundmacher - One of the best experts on this subject based on the ideXlab platform.
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identification of key transport phenomena in High Temperature Reactors flow and heat transfer characteristics
Industrial & Engineering Chemistry Research, 2018Co-Authors: Georg Liesche, Kai SundmacherAbstract:High-Temperature Reactors are employed to produce key intermediates within the chemical value chain such as synthesis gas and hydrogen cyanide. The drawback of those Reactors is their High energy c...
G Cao - One of the best experts on this subject based on the ideXlab platform.
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phenomenology methods and experimental program for fluoride salt cooled High Temperature Reactors fhrs
Progress in Nuclear Energy, 2014Co-Authors: Nicolas Zweibaum, Michael R Laufer, Charles Forsberg, G Cao, Mark H Anderson, Anselmo T Cisneros, Brian C Kelleher, Raluca O Scarlat, Jeffrey E Seifried, Ehud GreenspanAbstract:Abstract Due to their combination of High-Temperature coated-particle fuel, molten salt coolant and related materials requirements, fluoride-salt-cooled, High-Temperature Reactors (FHRs) exhibit different thermal hydraulic, neutronic and structural mechanics phenomena compared to conventional and more extensively studied other advanced nuclear reactor concepts. This paper Highlights key phenomena unique to FHRs, and reviews general issues for developing, verifying, and validating evaluation models for FHR technology that may apply to other advanced Reactors. System response codes that are appropriate to predict the behavior of FHRs under steady-state operation and licensing basis events are identified, along with experimental data needs to validate these codes. FHR materials requirements are Highlighted, and the missions and licensing program for an FHR test reactor, providing ultimate validation data and proof of concept before a commercial prototype is built, are presented. This review draws upon information compiled in a series of four white papers based on FHR experts workshops held in 2012 in the U.S.
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spectral emissivity of candidate alloys for very High Temperature Reactors in High Temperature air environment
Journal of Nuclear Materials, 2013Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, Todd R AllenAbstract:Abstract Emissivity measurements for candidate alloys for very High Temperature Reactors were carried out in a custom-built experimental facility, capable of both efficient and reliable measurements of spectral emissivities of multiple samples at High Temperatures. The alloys studied include 304 and 316 austenitic stainless steels, Alloy 617, and SA508 ferritic steel. The oxidation of alloys plays an important role in dictating emissivity values. The Higher chromium content of 304 and 316 austenitic stainless steels, and Alloy 617 results in an oxide layer only of sub-micron thickness even at 700 °C and consequently the emissivity of these alloys remains low. In contrast, the low alloy SA508 ferritic steel which contains no chromium develops a thicker oxide layer, and consequently exhibits Higher emissivity values.
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spectral emissivity measurements of candidate materials for very High Temperature Reactors
Nuclear Engineering and Design, 2012Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, Todd R AllenAbstract:Abstract Heat dissipation by radiation is an important consideration in VHTR components, particularly the reactor pressure vessel (RPV), because of the fourth power Temperature dependence of radiated heat. Since emissivity is the material property that dictates the ability to radiate heat, measurements of emissivities of materials that are being specifically considered for the construction of VHTR become important. Emissivity is a surface phenomenon and therefore compositional, structural, and topographical changes that occur at the surfaces of these materials as a result of their interactions with the environment at High Temperatures will alter their emissivities. With this background, an experimental system for the measurement of spectral emissivity has been designed and constructed. The system has been calibrated in conformance with U.S. DoE quality assurance standards using inert ceramic materials, boron nitride, silicon carbide, and aluminum oxide. The results of High Temperature emissivity measurements of potential VHTR materials such as ferritic steels SA 508, T22, T91 and austenitic alloys IN 800H, Haynes 230, IN 617, and 316 stainless steel have been presented.
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in situ measurements of spectral emissivity of materials for very High Temperature Reactors
Nuclear Technology, 2011Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, T L Malaney, S R Slattery, Todd R AllenAbstract:AbstractAn experimental facility for in situ measurements of High-Temperature spectral emissivity of materials in environments of interest to the gas-cooled very High Temperature reactor (VHTR) has been developed. The facility is capable of measuring emissivities of seven materials in a single experiment, thereby enhancing the accuracy in measurements due to even minor systemic variations in Temperatures and environments. The system consists of a cylindrical silicon carbide (SiC) block with seven sample cavities and a deep blackbody cavity, a detailed optical system, and a Fourier transform infrared spectrometer. The reliability of the facility has been confirmed by comparing measured spectral emissivities of SiC, boron nitride, and alumina (Al2O3) at 600°C against those reported in literature. The spectral emissivities of two candidate alloys for VHTR, INCONEL® alloy 617 (INCONEL is a registered trademark of the Special Metals Corporation group of companies) and SA508 steel, in air environment at 700°C w...
Daniel Feuermann - One of the best experts on this subject based on the ideXlab platform.
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A High-irradiance solar furnace for photovoltaic characterization and nanomaterial synthesis
Solar Energy Materials and Solar Cells, 2011Co-Authors: Jeffrey M. Gordon, Dotan Babai, Daniel FeuermannAbstract:Abstract A High-irradiance solar furnace geared toward (a) elucidating the distinctive physics of concentrator photovoltaics and (b) driving High-Temperature Reactors for the generation of novel nanostructures is described, with a target irradiance up to 12 W/mm 2 . The opto-mechanical design permits real-sun flash illumination at a millisecond time scale so that solar cells can be characterized with only insubstantial increases in cell Temperature even at irradiance levels of thousands of suns.
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A High irradiance solar furnace for solar cell characterization and nanomaterial synthesis
High and Low Concentrator Systems for Solar Electric Applications V, 2010Co-Authors: Dotan Babai, Daniel Feuermann, Jeffrey M. GordonAbstract:A High irradiance solar furnace geared toward elucidating the distinctive physics of concentrator photovoltaics and driving High-Temperature Reactors for the generation of novel nanostructures is described, with a target irradiance up to 12 W/mm 2 . The opto-mechanical design permits real-sun flash illumination at a millisecond time scale so that solar cells can be characterized with only insubstantial increases in cell Temperature even at irradiance levels of thousands of suns.
Todd R Allen - One of the best experts on this subject based on the ideXlab platform.
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ASME Boiler and Pressure Vessel Code Roadmap for Compact Heat Exchangers in High Temperature Reactors
Journal of Nuclear Engineering and Radiation Science, 2020Co-Authors: Robert Keating, Todd R Allen, Suzanne Mckillop, Mark AndersonAbstract:Abstract The mission of the U.S. Department of Energy (DOE), Office of Nuclear Energy is to advance nuclear power in order to meet the nation's energy, environmental, and energy security needs. Advanced High Temperature reactor systems will require compact heat exchangers (CHXs) for the next generation of nuclear Reactors. The DOE is sponsoring research to support the development and deployment of CHXs for use in High Temperature advanced Reactors. The project is being executed by an Integrated Research Project (IRP) that includes university research institutes, national laboratories, manufacturers, and industry experts. The objective is to enable the use of CHX designs in advanced reactor service. A necessary step for achieving this objective is to ensure that the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section III, Division 5 has rules for the construction of CHXs for nuclear service. However, construction rules alone are not sufficient to deploy a CHX in an advanced reactor. A strategy for ASME Boiler and Pressure Vessel Code, Section XI, Inservice Inspection (ISI) of a heat exchanger in an operating nuclear reactor will also be required. The purpose of this ASME Code Roadmap is to identify the research gaps impeding the development of suitable construction and ISI rules for CHXs for High Temperature reactor service and to provide a framework to utilize the research project results consistent with the expectations and needs of the industry and future owners.
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spectral emissivity of candidate alloys for very High Temperature Reactors in High Temperature air environment
Journal of Nuclear Materials, 2013Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, Todd R AllenAbstract:Abstract Emissivity measurements for candidate alloys for very High Temperature Reactors were carried out in a custom-built experimental facility, capable of both efficient and reliable measurements of spectral emissivities of multiple samples at High Temperatures. The alloys studied include 304 and 316 austenitic stainless steels, Alloy 617, and SA508 ferritic steel. The oxidation of alloys plays an important role in dictating emissivity values. The Higher chromium content of 304 and 316 austenitic stainless steels, and Alloy 617 results in an oxide layer only of sub-micron thickness even at 700 °C and consequently the emissivity of these alloys remains low. In contrast, the low alloy SA508 ferritic steel which contains no chromium develops a thicker oxide layer, and consequently exhibits Higher emissivity values.
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spectral emissivity measurements of candidate materials for very High Temperature Reactors
Nuclear Engineering and Design, 2012Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, Todd R AllenAbstract:Abstract Heat dissipation by radiation is an important consideration in VHTR components, particularly the reactor pressure vessel (RPV), because of the fourth power Temperature dependence of radiated heat. Since emissivity is the material property that dictates the ability to radiate heat, measurements of emissivities of materials that are being specifically considered for the construction of VHTR become important. Emissivity is a surface phenomenon and therefore compositional, structural, and topographical changes that occur at the surfaces of these materials as a result of their interactions with the environment at High Temperatures will alter their emissivities. With this background, an experimental system for the measurement of spectral emissivity has been designed and constructed. The system has been calibrated in conformance with U.S. DoE quality assurance standards using inert ceramic materials, boron nitride, silicon carbide, and aluminum oxide. The results of High Temperature emissivity measurements of potential VHTR materials such as ferritic steels SA 508, T22, T91 and austenitic alloys IN 800H, Haynes 230, IN 617, and 316 stainless steel have been presented.
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in situ measurements of spectral emissivity of materials for very High Temperature Reactors
Nuclear Technology, 2011Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, T L Malaney, S R Slattery, Todd R AllenAbstract:AbstractAn experimental facility for in situ measurements of High-Temperature spectral emissivity of materials in environments of interest to the gas-cooled very High Temperature reactor (VHTR) has been developed. The facility is capable of measuring emissivities of seven materials in a single experiment, thereby enhancing the accuracy in measurements due to even minor systemic variations in Temperatures and environments. The system consists of a cylindrical silicon carbide (SiC) block with seven sample cavities and a deep blackbody cavity, a detailed optical system, and a Fourier transform infrared spectrometer. The reliability of the facility has been confirmed by comparing measured spectral emissivities of SiC, boron nitride, and alumina (Al2O3) at 600°C against those reported in literature. The spectral emissivities of two candidate alloys for VHTR, INCONEL® alloy 617 (INCONEL is a registered trademark of the Special Metals Corporation group of companies) and SA508 steel, in air environment at 700°C w...
Mark H Anderson - One of the best experts on this subject based on the ideXlab platform.
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phenomenology methods and experimental program for fluoride salt cooled High Temperature Reactors fhrs
Progress in Nuclear Energy, 2014Co-Authors: Nicolas Zweibaum, Michael R Laufer, Charles Forsberg, G Cao, Mark H Anderson, Anselmo T Cisneros, Brian C Kelleher, Raluca O Scarlat, Jeffrey E Seifried, Ehud GreenspanAbstract:Abstract Due to their combination of High-Temperature coated-particle fuel, molten salt coolant and related materials requirements, fluoride-salt-cooled, High-Temperature Reactors (FHRs) exhibit different thermal hydraulic, neutronic and structural mechanics phenomena compared to conventional and more extensively studied other advanced nuclear reactor concepts. This paper Highlights key phenomena unique to FHRs, and reviews general issues for developing, verifying, and validating evaluation models for FHR technology that may apply to other advanced Reactors. System response codes that are appropriate to predict the behavior of FHRs under steady-state operation and licensing basis events are identified, along with experimental data needs to validate these codes. FHR materials requirements are Highlighted, and the missions and licensing program for an FHR test reactor, providing ultimate validation data and proof of concept before a commercial prototype is built, are presented. This review draws upon information compiled in a series of four white papers based on FHR experts workshops held in 2012 in the U.S.
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spectral emissivity of candidate alloys for very High Temperature Reactors in High Temperature air environment
Journal of Nuclear Materials, 2013Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, Todd R AllenAbstract:Abstract Emissivity measurements for candidate alloys for very High Temperature Reactors were carried out in a custom-built experimental facility, capable of both efficient and reliable measurements of spectral emissivities of multiple samples at High Temperatures. The alloys studied include 304 and 316 austenitic stainless steels, Alloy 617, and SA508 ferritic steel. The oxidation of alloys plays an important role in dictating emissivity values. The Higher chromium content of 304 and 316 austenitic stainless steels, and Alloy 617 results in an oxide layer only of sub-micron thickness even at 700 °C and consequently the emissivity of these alloys remains low. In contrast, the low alloy SA508 ferritic steel which contains no chromium develops a thicker oxide layer, and consequently exhibits Higher emissivity values.
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spectral emissivity measurements of candidate materials for very High Temperature Reactors
Nuclear Engineering and Design, 2012Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, Todd R AllenAbstract:Abstract Heat dissipation by radiation is an important consideration in VHTR components, particularly the reactor pressure vessel (RPV), because of the fourth power Temperature dependence of radiated heat. Since emissivity is the material property that dictates the ability to radiate heat, measurements of emissivities of materials that are being specifically considered for the construction of VHTR become important. Emissivity is a surface phenomenon and therefore compositional, structural, and topographical changes that occur at the surfaces of these materials as a result of their interactions with the environment at High Temperatures will alter their emissivities. With this background, an experimental system for the measurement of spectral emissivity has been designed and constructed. The system has been calibrated in conformance with U.S. DoE quality assurance standards using inert ceramic materials, boron nitride, silicon carbide, and aluminum oxide. The results of High Temperature emissivity measurements of potential VHTR materials such as ferritic steels SA 508, T22, T91 and austenitic alloys IN 800H, Haynes 230, IN 617, and 316 stainless steel have been presented.
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in situ measurements of spectral emissivity of materials for very High Temperature Reactors
Nuclear Technology, 2011Co-Authors: G Cao, S J Weber, S O Martin, Kumar Sridharan, Mark H Anderson, T L Malaney, S R Slattery, Todd R AllenAbstract:AbstractAn experimental facility for in situ measurements of High-Temperature spectral emissivity of materials in environments of interest to the gas-cooled very High Temperature reactor (VHTR) has been developed. The facility is capable of measuring emissivities of seven materials in a single experiment, thereby enhancing the accuracy in measurements due to even minor systemic variations in Temperatures and environments. The system consists of a cylindrical silicon carbide (SiC) block with seven sample cavities and a deep blackbody cavity, a detailed optical system, and a Fourier transform infrared spectrometer. The reliability of the facility has been confirmed by comparing measured spectral emissivities of SiC, boron nitride, and alumina (Al2O3) at 600°C against those reported in literature. The spectral emissivities of two candidate alloys for VHTR, INCONEL® alloy 617 (INCONEL is a registered trademark of the Special Metals Corporation group of companies) and SA508 steel, in air environment at 700°C w...