The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on th...The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on this concept,a stepwise radial fuel shuffling strategy was proposed and applied to a sodium-cooled fast reactor(SFR)loading metallic 238U fuel.The multi-group deterministic neutronic code ERANOS with JEFF3.1 data library was used as a basic tool to perform the neutronics and burnup calculations.The inward fuel shuffling calculations were first performed in a 1-D cylindrical case for parametric understanding,and then extended to a 2-D R-Z case.The shuffling calculations for the 1-D and 2-D SFR model yielded some interesting results.The asymptotic keff varied parabolically with the characteristic fluence,while the burnup increased linearly.The highest burnup achieved in 2-D case was 38%.The power peak shifted from the fuel outlet side(core centre)to the fuel inlet side(core periphery)in both 1-D and 2-D cases and the corresponding peaking factor decreased dramatically along with the characteristic fluence.The present research demonstrated that the proposed stepwise radial fuel shuffling in the sodium fast reactor achieved the characteristics of the traveling wave reactor.展开更多
Advanced nuclear reactors offer safe, clean, and reliable energy at the global scale. The development of such devices relies heavily upon computational models, from the pre-conceptual stages through detailed design, l...Advanced nuclear reactors offer safe, clean, and reliable energy at the global scale. The development of such devices relies heavily upon computational models, from the pre-conceptual stages through detailed design, licensing, and operation. An integrated reactor modeling framework that enables seamless communication, coupling, automation, and continuous development brings significant new capabilities and efficiencies to the practice of reactor design. In such a system, key performance metrics （e.g., optimal fuel management, peak cladding temperature in design-basis accidents, levelized cost of electricity） can be explicitly linked to design inputs （e.g., assembly duct thickness, tolerances）, enabling an exceptional level of design consistency. Coupled with high-performance computing, thousands of integrated cases can be executed simultaneously to analyze the full system, perform complete sensitivity studies, and efficiently and robustly evaluate various design tradeoffs. TerraPower has developed such a tool-the Advanced Reactor Modeling Interface （ARMI） code system-and has deployed it to support the TerraPower Traveling Wave Reactor design and other innovative energy products currently under development. The ARMI code system employs pre-existing tools with strong pedigrees alongside many new physics and data management modules necessary for innovative design. Verification and validation against previous and new physical measurements, which remain an essential element of any sound design, are being carried out. This paper summarizes the integrated core engineering tools and practices in production at TerraPower.展开更多
New results of two computer experiments on modeling of superthermal neutron-nuclear combustion of natural uranium for two different flux densities of external neutron source and duration of half a year each are presen...New results of two computer experiments on modeling of superthermal neutron-nuclear combustion of natural uranium for two different flux densities of external neutron source and duration of half a year each are presented. The simulation results demonstrate the dependence of the autowave combustion modes on the parameters of the external source.展开更多
The promoting effect of ultrasonic wave on the hydrodynamics and mass transfer characteristics of the airlift loop reactor was studied. The effect of the airlift reactor and ultrasonic wave on the reactor’s gas holdu...The promoting effect of ultrasonic wave on the hydrodynamics and mass transfer characteristics of the airlift loop reactor was studied. The effect of the airlift reactor and ultrasonic wave on the reactor’s gas holdup, liquid circulation velocity, mixing time and overall volumetric mass transfer coefficient respectively with and without the presence of ultrasonic wave is empathetically examined and compared. The experiment has proven that the incorporation of ultrasonic wave has no effect on the gas holdup but has the tendency to gradually decrease the liquid circulation velocity and increase the overall volumetric mass transfer coefficient; the effect on the mixing time is relatively complex. At low gas velocity, low powered ultrasonic wave promotes the radial mixing of fluid; with the increase of ultrasonic power, ultrasonic vibration obstructs the radial mixing of fluid. Therefore, there exists an optimal ultrasonic power. Moreover, the effect of ultrasonic wave on the mixing time gradually decreases with the increase of the superficial gas velocity. Correlations were also proposed for the hydrodynamics and mass transfer characteristics of the reactor.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11105103)the Doctoral Fund of the Ministry of Education of China(Grant No.20110201120046)
文摘The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on this concept,a stepwise radial fuel shuffling strategy was proposed and applied to a sodium-cooled fast reactor(SFR)loading metallic 238U fuel.The multi-group deterministic neutronic code ERANOS with JEFF3.1 data library was used as a basic tool to perform the neutronics and burnup calculations.The inward fuel shuffling calculations were first performed in a 1-D cylindrical case for parametric understanding,and then extended to a 2-D R-Z case.The shuffling calculations for the 1-D and 2-D SFR model yielded some interesting results.The asymptotic keff varied parabolically with the characteristic fluence,while the burnup increased linearly.The highest burnup achieved in 2-D case was 38%.The power peak shifted from the fuel outlet side(core centre)to the fuel inlet side(core periphery)in both 1-D and 2-D cases and the corresponding peaking factor decreased dramatically along with the characteristic fluence.The present research demonstrated that the proposed stepwise radial fuel shuffling in the sodium fast reactor achieved the characteristics of the traveling wave reactor.
文摘Advanced nuclear reactors offer safe, clean, and reliable energy at the global scale. The development of such devices relies heavily upon computational models, from the pre-conceptual stages through detailed design, licensing, and operation. An integrated reactor modeling framework that enables seamless communication, coupling, automation, and continuous development brings significant new capabilities and efficiencies to the practice of reactor design. In such a system, key performance metrics （e.g., optimal fuel management, peak cladding temperature in design-basis accidents, levelized cost of electricity） can be explicitly linked to design inputs （e.g., assembly duct thickness, tolerances）, enabling an exceptional level of design consistency. Coupled with high-performance computing, thousands of integrated cases can be executed simultaneously to analyze the full system, perform complete sensitivity studies, and efficiently and robustly evaluate various design tradeoffs. TerraPower has developed such a tool-the Advanced Reactor Modeling Interface （ARMI） code system-and has deployed it to support the TerraPower Traveling Wave Reactor design and other innovative energy products currently under development. The ARMI code system employs pre-existing tools with strong pedigrees alongside many new physics and data management modules necessary for innovative design. Verification and validation against previous and new physical measurements, which remain an essential element of any sound design, are being carried out. This paper summarizes the integrated core engineering tools and practices in production at TerraPower.
文摘New results of two computer experiments on modeling of superthermal neutron-nuclear combustion of natural uranium for two different flux densities of external neutron source and duration of half a year each are presented. The simulation results demonstrate the dependence of the autowave combustion modes on the parameters of the external source.
文摘The promoting effect of ultrasonic wave on the hydrodynamics and mass transfer characteristics of the airlift loop reactor was studied. The effect of the airlift reactor and ultrasonic wave on the reactor’s gas holdup, liquid circulation velocity, mixing time and overall volumetric mass transfer coefficient respectively with and without the presence of ultrasonic wave is empathetically examined and compared. The experiment has proven that the incorporation of ultrasonic wave has no effect on the gas holdup but has the tendency to gradually decrease the liquid circulation velocity and increase the overall volumetric mass transfer coefficient; the effect on the mixing time is relatively complex. At low gas velocity, low powered ultrasonic wave promotes the radial mixing of fluid; with the increase of ultrasonic power, ultrasonic vibration obstructs the radial mixing of fluid. Therefore, there exists an optimal ultrasonic power. Moreover, the effect of ultrasonic wave on the mixing time gradually decreases with the increase of the superficial gas velocity. Correlations were also proposed for the hydrodynamics and mass transfer characteristics of the reactor.
