The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Cenxi Yuan - One of the best experts on this subject based on the ideXlab platform.
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Recent studies on Potential Accident-tolerant fuel-cladding systems in light water reactors
Nuclear Science and Techniques, 2020Co-Authors: Shengli Chen, Cenxi YuanAbstract:Accident-tolerant fuel (ATF) has attracted considerable research attention since the 2011 Fukushima nuclear disaster. To improve the Accident tolerance of the fuel-cladding systems in the current light-water reactors, it is proposed to develop and deploy (1) an enhanced Zr-based alloy or coated zircaloy for the fuel cladding, (2) alternative cladding materials with better Accident tolerance, and (3) alternative fuels with enhanced Accident tolerance and/or a higher U density. This review presents the features of the current UO2–zircaloy system. Different techniques and characters to develop coating materials and enhanced Zr-based alloys are summarized. The features of several selected alternative fuels and cladding materials are reviewed and discussed. The neutronic evaluations of alternative fuel-cladding systems are analyzed. It is expected that one or more types of ATF-cladding systems discussed in the present review will be implemented in commercial reactors.
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neutronic analysis on Potential Accident tolerant fuel cladding combination u _3 si _2 fecral
arXiv: Applied Physics, 2017Co-Authors: Shengli Chen, Cenxi YuanAbstract:Neutronic performance is investigated for a Potential Accident tolerant fuel (ATF),which consists of U$_3$Si$_2$ fuel and FeCrAl cladding. In comparison with current UO$_2$-Zr system, FeCrAl has a better oxidation resistance but a larger thermal neutron absorption cross section. U$_3$Si$_2$ has a higher thermal conductivity and a higher uranium density, which can compensate the reactivity suppressed by FeCrAl. Based on neutronic investigations, a possible U$_3$Si$_2$-FeCrAl fuel-cladding systemis taken into consideration. Fundamental properties of the suggested fuel-cladding combination are investigated in a fuel assembly.These properties include moderator and fuel temperature coefficients, control rods worth, radial power distribution (in a fuel rod), and different void reactivity coefficients. The present work proves that the new combination has less reactivity variation during its service lifetime. Although, compared with the current system, it has a little larger deviation on power distribution and a little less negative temperature coefficient and void reactivity coefficient and its control rods worth is less important, variations of these parameters are less important during the service lifetime of fuel. Hence, U$_3$Si$_2$-FeCrAl system is a Potential ATF candidate from a neutronic view.
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neutronic analysis on Potential Accident tolerant fuel cladding combination u3si2 fecral
Science and Technology of Nuclear Installations, 2017Co-Authors: Shengli Chen, Cenxi YuanAbstract:Neutronic performance is investigated for a Potential Accident tolerant fuel (ATF), which consists of U3Si2 fuel and FeCrAl cladding. In comparison with current UO2-Zr system, FeCrAl has a better oxidation resistance but a larger thermal neutron absorption cross section. U3Si2 has a higher thermal conductivity and a higher uranium density, which can compensate the reactivity suppressed by FeCrAl. Based on neutronic investigations, a possible U3Si2-FeCrAl fuel-cladding system is taken into consideration. Fundamental properties of the suggested fuel-cladding combination are investigated in a fuel assembly. These properties include moderator and fuel temperature coefficients, control rods worth, radial power distribution (in a fuel rod), and different void reactivity coefficients. The present work proves that the new combination has less reactivity variation during its service lifetime. Although, compared with the current system, it has a little larger deviation on power distribution and a little less negative temperature coefficient and void reactivity coefficient and its control rods worth is less important, variations of these parameters are less important during the service lifetime of fuel. Hence, U3Si2-FeCrAl system is a Potential ATF candidate from a neutronic view.
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Neutronic Analysis on Potential Accident Tolerant Fuel-Cladding Combination U$_3$Si$_2$-FeCrAl
Science and Technology of Nuclear Installations, 2017Co-Authors: Shengli Chen, Cenxi YuanAbstract:Neutronic performance is investigated for a Potential Accident tolerant fuel (ATF),which consists of U$_3$Si$_2$ fuel and FeCrAl cladding. In comparison with current UO$_2$-Zr system, FeCrAl has a better oxidation resistance but a larger thermal neutron absorption cross section. U$_3$Si$_2$ has a higher thermal conductivity and a higher uranium density, which can compensate the reactivity suppressed by FeCrAl. Based on neutronic investigations, a possible U$_3$Si$_2$-FeCrAl fuel-cladding systemis taken into consideration. Fundamental properties of the suggested fuel-cladding combination are investigated in a fuel assembly.These properties include moderator and fuel temperature coefficients, control rods worth, radial power distribution (in a fuel rod), and different void reactivity coefficients. The present work proves that the new combination has less reactivity variation during its service lifetime. Although, compared with the current system, it has a little larger deviation on power distribution and a little less negative temperature coefficient and void reactivity coefficient and its control rods worth is less important, variations of these parameters are less important during the service lifetime of fuel. Hence, U$_3$Si$_2$-FeCrAl system is a Potential ATF candidate from a neutronic view.
Shengli Chen - One of the best experts on this subject based on the ideXlab platform.
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Recent studies on Potential Accident-tolerant fuel-cladding systems in light water reactors
Nuclear Science and Techniques, 2020Co-Authors: Shengli Chen, Cenxi YuanAbstract:Accident-tolerant fuel (ATF) has attracted considerable research attention since the 2011 Fukushima nuclear disaster. To improve the Accident tolerance of the fuel-cladding systems in the current light-water reactors, it is proposed to develop and deploy (1) an enhanced Zr-based alloy or coated zircaloy for the fuel cladding, (2) alternative cladding materials with better Accident tolerance, and (3) alternative fuels with enhanced Accident tolerance and/or a higher U density. This review presents the features of the current UO2–zircaloy system. Different techniques and characters to develop coating materials and enhanced Zr-based alloys are summarized. The features of several selected alternative fuels and cladding materials are reviewed and discussed. The neutronic evaluations of alternative fuel-cladding systems are analyzed. It is expected that one or more types of ATF-cladding systems discussed in the present review will be implemented in commercial reactors.
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neutronic analysis on Potential Accident tolerant fuel cladding combination u _3 si _2 fecral
arXiv: Applied Physics, 2017Co-Authors: Shengli Chen, Cenxi YuanAbstract:Neutronic performance is investigated for a Potential Accident tolerant fuel (ATF),which consists of U$_3$Si$_2$ fuel and FeCrAl cladding. In comparison with current UO$_2$-Zr system, FeCrAl has a better oxidation resistance but a larger thermal neutron absorption cross section. U$_3$Si$_2$ has a higher thermal conductivity and a higher uranium density, which can compensate the reactivity suppressed by FeCrAl. Based on neutronic investigations, a possible U$_3$Si$_2$-FeCrAl fuel-cladding systemis taken into consideration. Fundamental properties of the suggested fuel-cladding combination are investigated in a fuel assembly.These properties include moderator and fuel temperature coefficients, control rods worth, radial power distribution (in a fuel rod), and different void reactivity coefficients. The present work proves that the new combination has less reactivity variation during its service lifetime. Although, compared with the current system, it has a little larger deviation on power distribution and a little less negative temperature coefficient and void reactivity coefficient and its control rods worth is less important, variations of these parameters are less important during the service lifetime of fuel. Hence, U$_3$Si$_2$-FeCrAl system is a Potential ATF candidate from a neutronic view.
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neutronic analysis on Potential Accident tolerant fuel cladding combination u3si2 fecral
Science and Technology of Nuclear Installations, 2017Co-Authors: Shengli Chen, Cenxi YuanAbstract:Neutronic performance is investigated for a Potential Accident tolerant fuel (ATF), which consists of U3Si2 fuel and FeCrAl cladding. In comparison with current UO2-Zr system, FeCrAl has a better oxidation resistance but a larger thermal neutron absorption cross section. U3Si2 has a higher thermal conductivity and a higher uranium density, which can compensate the reactivity suppressed by FeCrAl. Based on neutronic investigations, a possible U3Si2-FeCrAl fuel-cladding system is taken into consideration. Fundamental properties of the suggested fuel-cladding combination are investigated in a fuel assembly. These properties include moderator and fuel temperature coefficients, control rods worth, radial power distribution (in a fuel rod), and different void reactivity coefficients. The present work proves that the new combination has less reactivity variation during its service lifetime. Although, compared with the current system, it has a little larger deviation on power distribution and a little less negative temperature coefficient and void reactivity coefficient and its control rods worth is less important, variations of these parameters are less important during the service lifetime of fuel. Hence, U3Si2-FeCrAl system is a Potential ATF candidate from a neutronic view.
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Neutronic Analysis on Potential Accident Tolerant Fuel-Cladding Combination U$_3$Si$_2$-FeCrAl
Science and Technology of Nuclear Installations, 2017Co-Authors: Shengli Chen, Cenxi YuanAbstract:Neutronic performance is investigated for a Potential Accident tolerant fuel (ATF),which consists of U$_3$Si$_2$ fuel and FeCrAl cladding. In comparison with current UO$_2$-Zr system, FeCrAl has a better oxidation resistance but a larger thermal neutron absorption cross section. U$_3$Si$_2$ has a higher thermal conductivity and a higher uranium density, which can compensate the reactivity suppressed by FeCrAl. Based on neutronic investigations, a possible U$_3$Si$_2$-FeCrAl fuel-cladding systemis taken into consideration. Fundamental properties of the suggested fuel-cladding combination are investigated in a fuel assembly.These properties include moderator and fuel temperature coefficients, control rods worth, radial power distribution (in a fuel rod), and different void reactivity coefficients. The present work proves that the new combination has less reactivity variation during its service lifetime. Although, compared with the current system, it has a little larger deviation on power distribution and a little less negative temperature coefficient and void reactivity coefficient and its control rods worth is less important, variations of these parameters are less important during the service lifetime of fuel. Hence, U$_3$Si$_2$-FeCrAl system is a Potential ATF candidate from a neutronic view.
Marco Cattani - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Safety Performance of Turbo-Roundabouts by Means of a Potential Accident Rate Model
THE BALTIC JOURNAL OF ROAD AND BRIDGE ENGINEERING, 2015Co-Authors: Raffaele Mauro, Marco Cattani, Marco GuerrieriAbstract:Turbo roundabouts are a particular road intersection layout, designed to increase the safety of double-lane roundabouts, while maintaining their excellent capacity. The main feature of this new concept of roundabout is the impossibility to move from one lane to another, provided by physical barriers marking the lanes. The paper shows an application to turbo roundabouts of a Potential Accident rate model, aiming to evaluate their safety improvement. The model is based on the concept of Potential conflict: each vehicle involved in a general intersection performs a series of maneuvers which Potentially imply a crash, according to the actual traffic. The number of Accidents related to each critical maneuver is proportional to the number of times this maneuver occurs at the intersection. In order to define the critical maneuvers, and hence the relevant Potential conflicts, specific crash typologies for roundabouts are adopted. Traffic volumes are required, to evaluate the expected number of Accidents, and also probabilities of Accident for every critical maneuver. These ratios were obtained by a model calibration, based on actual Accident and traffic data recorded on conventional single and double-lane roundabouts. The model was then used to compare four-leg turbo roundabouts to conventional roundabouts. The comparisons have taken into account only basic differences in layout, such as geometric elements, that also play a role in determining safety performances of a roundabout. The results obtained show that turbo roundabouts significantly decrease the Accident rate with respect to conventional roundabouts, by eliminating conflicts between circulating and exiting vehicles.
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Potential Accident Rate of Turbo-Roundabouts
2010Co-Authors: Raffaele Mauro, Marco CattaniAbstract:Turbo-roundabouts are a particular road intersection layout, designed to increase the safety of double-lane roundabouts, while maintaining their excellent capacity. The main feature of this new concept of roundabout is the impossibility to move from one lane to another, provided by physical barriers marking the lanes. This helps to prevent side collisions crossing the roundabout. The paper shows an application to turbo-roundabouts of a Potential Accident rate model, aiming to evaluate their safety improvement. The model is based on the concept of Potential conflict: each vehicle involved in a general intersection performs a series of maneuvers which may or may not imply a crash, according to the actual traffic. The number of Accidents related to each critical maneuver is proportional to the number of times this maneuver occurs at the intersection. In order to define the critical maneuvers, and hence the relevant Potential conflicts, specific crash typologies for roundabouts are adopted. Traffic volumes are required, to evaluate the expected number of Accidents, and also probabilities of Accident, i.e. Accident / Potential conflicts, for every critical maneuver. These ratios were obtained by a model calibration, based on actual Accident and traffic data recorded on conventional single-lane and double-lane roundabouts. The model was then used to compare four-leg turbo-roundabouts to conventional roundabouts, by varying different parameters, as lane number, turning patterns and traffic flows. The comparisons have taken into account only basic differences in layout, without dealing with other relevant features, such as geometric elements or marking options, that could also play a role in determining safety performances of a roundabout. Considering all the limits of the analysis, however, the results obtained show that turbo-roundabouts can significantly decrease the Accident rate with respect to conventional roundabouts, by eliminating conflicts between circulating and exiting vehicles.
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A Model to Evaluate the Potential Accident Rate at Single-Lane and Double-Lane Roundabouts
2005Co-Authors: Raffaele Mauro, Marco CattaniAbstract:The paper presents a model for the Potential Accident rate evaluation in large and medium roundabouts, both single-lane and double-lane. The model is based on dynamical considerations and on user behavior at the intersection. To define the relevant Potential conflicts, crash typologies specific for roundabouts are adopted. Then an illustrative model calibration is shown, on the basis of available data. Finally, some sensitivity analyses are performed, to test the model behavior by varying some parameter values. The present model can provide a further element for the choice between alternative typologies of intersection for re-qualification and adjustment of road junctions.
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Model to Evaluate Potential Accident Rate at Roundabouts
Journal of Transportation Engineering, 2004Co-Authors: Raffaele Mauro, Marco CattaniAbstract:The increasing use of roundabouts for plane junctions calls for an evaluation of the Potential Accident rate for this kind of intersection. This gives a further element for the choice between alternative typologies of intersection for the requalification and the adjustment of road junctions. This paper presents a model for the Potential Accident rate evaluation in large and medium roundabouts. The model is based on dynamical considerations and on the user's behavior crossing the intersection. The model's response to the traffic conditions in the intersection and to capacity formulations is also analyzed.
Kumar Sridharan - One of the best experts on this subject based on the ideXlab platform.
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Experimental Evaluation of Cold Spray FeCrAl Alloys Coated Zirconium-alloy for Potential Accident Tolerant Fuel Cladding
Nuclear Materials and Energy, 2019Co-Authors: Tyler Dabney, Greg Johnson, Hwasung Yeom, Ben Maier, Jorie Walters, Kumar SridharanAbstract:Abstract Two FeCrAl alloy coatings with different Cr and Al contents were deposited on Zr-alloy substrates via the cold spray deposition method to study the efficacy of these coatings to improve the Accident tolerance of Zr-alloy fuel cladding in light water reactors (LWRs). First, the coatings were tested in a 400 °C steam autoclave for 72 h as an accelerated method to simulate the normal LWR operating conditions. In these tests, both coatings resulted in notable improvements in oxidation resistance compared to the Zr-alloy, with the higher Cr containing coating exhibiting a thinner oxide layer. Both coatings provided good oxidation resistance when tested in 1200 °C ambient air environment; however, the formation of a low melting point eutectic (~928 °C) between Fe and Zr resulted in significant melting associated with inter-diffusion between Fe in the coating and the Zr in the substrate. Therefore, to take advantage of the superior oxidation resistance that FeCrAl coatings can provide, a Mo interlayer was deposited, also by the cold spray process, in-between the protective FeCrAl coating and the Zr-alloy substrate, thus creating a dual cold spray layer Accident tolerant coated cladding concept. The wear resistance of the FeCrAl coating was superior to the Zr-alloy substrate based on pin-on-disk wear tests, providing an indication of the benefits of such coatings to reduce grit-to-rod fretting (GTRF) damage. The feedstock powders, microstructure, phases, hardness of coatings, as well as oxide and inter-diffusion layers of oxidized coatings were examined using SEM, XRD, and XPS characterization techniques.
Raffaele Mauro - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Safety Performance of Turbo-Roundabouts by Means of a Potential Accident Rate Model
THE BALTIC JOURNAL OF ROAD AND BRIDGE ENGINEERING, 2015Co-Authors: Raffaele Mauro, Marco Cattani, Marco GuerrieriAbstract:Turbo roundabouts are a particular road intersection layout, designed to increase the safety of double-lane roundabouts, while maintaining their excellent capacity. The main feature of this new concept of roundabout is the impossibility to move from one lane to another, provided by physical barriers marking the lanes. The paper shows an application to turbo roundabouts of a Potential Accident rate model, aiming to evaluate their safety improvement. The model is based on the concept of Potential conflict: each vehicle involved in a general intersection performs a series of maneuvers which Potentially imply a crash, according to the actual traffic. The number of Accidents related to each critical maneuver is proportional to the number of times this maneuver occurs at the intersection. In order to define the critical maneuvers, and hence the relevant Potential conflicts, specific crash typologies for roundabouts are adopted. Traffic volumes are required, to evaluate the expected number of Accidents, and also probabilities of Accident for every critical maneuver. These ratios were obtained by a model calibration, based on actual Accident and traffic data recorded on conventional single and double-lane roundabouts. The model was then used to compare four-leg turbo roundabouts to conventional roundabouts. The comparisons have taken into account only basic differences in layout, such as geometric elements, that also play a role in determining safety performances of a roundabout. The results obtained show that turbo roundabouts significantly decrease the Accident rate with respect to conventional roundabouts, by eliminating conflicts between circulating and exiting vehicles.
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Potential Accident Rate of Turbo-Roundabouts
2010Co-Authors: Raffaele Mauro, Marco CattaniAbstract:Turbo-roundabouts are a particular road intersection layout, designed to increase the safety of double-lane roundabouts, while maintaining their excellent capacity. The main feature of this new concept of roundabout is the impossibility to move from one lane to another, provided by physical barriers marking the lanes. This helps to prevent side collisions crossing the roundabout. The paper shows an application to turbo-roundabouts of a Potential Accident rate model, aiming to evaluate their safety improvement. The model is based on the concept of Potential conflict: each vehicle involved in a general intersection performs a series of maneuvers which may or may not imply a crash, according to the actual traffic. The number of Accidents related to each critical maneuver is proportional to the number of times this maneuver occurs at the intersection. In order to define the critical maneuvers, and hence the relevant Potential conflicts, specific crash typologies for roundabouts are adopted. Traffic volumes are required, to evaluate the expected number of Accidents, and also probabilities of Accident, i.e. Accident / Potential conflicts, for every critical maneuver. These ratios were obtained by a model calibration, based on actual Accident and traffic data recorded on conventional single-lane and double-lane roundabouts. The model was then used to compare four-leg turbo-roundabouts to conventional roundabouts, by varying different parameters, as lane number, turning patterns and traffic flows. The comparisons have taken into account only basic differences in layout, without dealing with other relevant features, such as geometric elements or marking options, that could also play a role in determining safety performances of a roundabout. Considering all the limits of the analysis, however, the results obtained show that turbo-roundabouts can significantly decrease the Accident rate with respect to conventional roundabouts, by eliminating conflicts between circulating and exiting vehicles.
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A Model to Evaluate the Potential Accident Rate at Single-Lane and Double-Lane Roundabouts
2005Co-Authors: Raffaele Mauro, Marco CattaniAbstract:The paper presents a model for the Potential Accident rate evaluation in large and medium roundabouts, both single-lane and double-lane. The model is based on dynamical considerations and on user behavior at the intersection. To define the relevant Potential conflicts, crash typologies specific for roundabouts are adopted. Then an illustrative model calibration is shown, on the basis of available data. Finally, some sensitivity analyses are performed, to test the model behavior by varying some parameter values. The present model can provide a further element for the choice between alternative typologies of intersection for re-qualification and adjustment of road junctions.
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Model to Evaluate Potential Accident Rate at Roundabouts
Journal of Transportation Engineering, 2004Co-Authors: Raffaele Mauro, Marco CattaniAbstract:The increasing use of roundabouts for plane junctions calls for an evaluation of the Potential Accident rate for this kind of intersection. This gives a further element for the choice between alternative typologies of intersection for the requalification and the adjustment of road junctions. This paper presents a model for the Potential Accident rate evaluation in large and medium roundabouts. The model is based on dynamical considerations and on the user's behavior crossing the intersection. The model's response to the traffic conditions in the intersection and to capacity formulations is also analyzed.