Coupling a CFD code with neutron kinetics and pin thermal models for nuclear reactor safety analyses

Natural circulation characteristics analysis of a small modular natural circulation lead–bismuth eutectic cooled fast reactor

The invention discloses an accelerator driven lead bismuth cooling subcritical traveling wave reactor. The accelerator driven lead bismuth cooling subcritical traveling wave reactor comprises a mobile neutron source target, a reactor core fuel, a reactor inner component, main heat exchangers, a reactor top cover, a reactor container and a main pump. An external source neutron is provided via the mobile neutron source target; the reactor is started and ignited; the traveling wave type reactor is driven to run under the subcritical state, and a combustion wave and a proliferation wave are continued; meanwhile, the heat of the reactor core is taken out by a lead bismuth cooling agent with good chemical inertness so as to guarantee the safety of the reactor, so that the requirement for high-enrichment-degree fissile nuclear fuels for realizing critical start by the critical traveling wave reactor is prevented, the requirements for reactor core materials and high fuel consumption by the traveling of the proliferation wave are lowered, and the practical feasibility, reliability and safety of the traveling wave reactor are improved effectively.

Accelerator driven lead bismuth cooling subcritical traveling wave reactor

The invention discloses an auxiliary heating system of a liquid heavy metal cooling natural circulating pool-type reactor. The system comprises a gas storage tank, a filter, a gas heater, a master gas input pipe, a main gas input valve, a main gas input pipe, an extraction opening, a main gas output valve, a main gas output pipe, a gas emergency input valve, a gas emergency input pipe, a gas emergency output valve, a gas emergency output pipe, a master gas output pipe, an air pump, a pipeline and other valves, wherein the pipeline is used for connecting the equipments. By adopting the system, the auxiliary heating function on liquid heavy metal inside the reactor is achieved inside a main container of the liquid heavy metal cooling natural circulating pool-type reactor and a ring cavity formed by a safe container, the system is simple in structure and has independence and reliability, members inside the reactor do not need to be added and started in operation, and the safety of the reactor can be effectively improved.

Auxiliary heating system in liquid state heavy metal cooling natural circulating pool type reactor

The invention discloses a gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system. According to the gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system, when a reactor is at normal operation conditions, a thermal separation valve is opened, an auxiliary heating valve is closed, a gas filter and a gas compressor are turned on, and thermal separation effect is realized by the gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system; when the reactor is at low-power running or shutdown condition, the auxiliary heating valve is opened, the thermal separation valve is closed, the gas filter, a gas heater, and the gas compressor are turned on, and auxiliary heating effect is realized by the gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system The gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system is simple in structure; activation is convenient; cold and hot pool separation and reactor internal cooling agent auxiliary heating of liquid metal cooling pool-type reactors can be realized at the same time; the complexity of reactor system structure is reduced effectively; reactor economical efficiency and security are increased; application range of the gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system is wide; the gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system is suitable for both liquid metal cooling pool-type reactors with forced circulation, and liquid metal cooling pool-type reactors with natural circulation.

Gas lift-based liquid metal cooling pool-type reactor multifunctional reactor internal thermal separation system

The invention discloses an auxiliary heating system for a liquid-metal-cooled natural circulation reactor. The auxiliary heating system comprises a nitrogen storage tank (1), a filter (2), a gas heater (3), a hot nitrogen input pipe (4), a main container (5), a safety container (6), gas extractors (7), pipelines and valves, wherein the pipelines and the valves are used for interconnecting devices. The system has the advantages that the function that a liquid-metal coolant in a liquid metal pool type reactor is subjected to auxiliary heating from the outside of the main container of the reactor is realized, the system is simple in structure, components in the reactor are not required for being added or started during operation, so that liquid metal in the main container can form micro natural circulation after the operation of the system, and meanwhile, the reliability and safety of the reactor can be effectively improved.

Auxiliary heating system for liquid-metal-cooled natural circulation reactor

Thermal stratification phenomena is observed in the upper plenum under the reactor scram transient of CLEAR-I. This will bring a bad effect on the natural circulation of the coolant Lead bismuth eutectic (LBE) in the primary circuit, which give rise to thermal stress on structural components. A CFD analysis of 2D axisymmetric domain to predict thermal stratification in scram conditions from full power operation has been performed by commercial code ANSYS 14.0. From the result, it can be seen that the thermal stratification can be formed in the hot pool under reactor scram conditions, the interface of the clear stratification was located below the inlet window of heat exchanger, but it will never stop the natural circulation of the primary circuit. The results obtained will be used to make an optimized design of China Lead Alloy Cooled Research Reactor (CLEAR-I).

CFD Analysis of Thermal Stratification of China Lead Alloy Cooled Research Reactor (CLEAR-I)

Because of heterogeneity of sub-channels geometry, a circumferential temperature distribution will exit in the fuel cladding surface during operating condition of a nuclear reactor, which will increase the maximum cladding surface temperature (MCST) However, this phenomenon cannot be obtained in single channel or sub-channel analyses approach Computational Fluid Dynamics (CFD) is a good method to study this problem In this paper, the circumferential temperature distribution on the fuel cladding surface of different sub-channels of China Lead-Alloy Cooled Research Reactor (CLEAR-I) were studied using FLUENT 140 Obvious circumferential temperature distributions were presented in results and the maximum circumferential temperature difference is 13°C in edge-channels This study will improve the precision in the MCST calculation of CLEAR-I and be a good guideline to the optimum design of CLEAR-I sub-channels configurationsCopyright © 2013 by ASME

Tao Zhou

Papers

Auxiliary heating system for liquid-metal-cooled natural circulation reactor

CFD Analysis of Thermal Stratification of China Lead Alloy Cooled Research Reactor (CLEAR-I)

CFD Analysis of Circumferential Temperature Distribution on Fuel Cladding Surface of China Lead Alloy Cooled Research Reactor (CLEAR-I)