System and method for enhancing passive natural circulation after a liquid metal cooling reactor loses flow

Abstract

The invention discloses a passive natural circulation intensifying system and method for a liquid metal cooled reactor after flow loss, and belongs to a safety protection system of the liquid metal cooled reactor. The passive natural circulation intensifying system comprises a high-pressure gas storage tank, a throttle valve, and a vertical pipeline and an inverted U-shaped pipeline which are positioned in a reactor. According to the system and the method disclosed by the invention, due to the connection design of the pipelines, when a main pump loses drive force, the liquid metal cooled pool type rector automatically triggers high-pressure gas to be injected into the upper part of a reactor core by a high-pressure injection tank without any signal transfer; and the injected gas pushes a coolant at an exit of the reactor core to flow upwards, and the natural circulation after a flow-loss accident is intensified. According to the system and the method disclosed by the invention, the automatic start of the reactor can be realized after the forced circulation is lost, and the natural circular flow of cold and hot pool loops is intensified so as to guarantee the effective cooling of the reactor core.

Description

technical field [0001] The invention relates to a safety protection system of a nuclear reactor, in particular to a waste heat discharge system and method of a metal cooling reactor. Background technique [0002] When the reactor loses the driving force of the primary circuit, that is, the loss of flow accident, the main pump of the primary circuit stops running, and the flow rate decreases rapidly. The coolant flow in the core is only driven by the gravity pressure caused by the density difference between the cold and hot pools of the circuit. . To ensure that the formed natural circulation flow has sufficient flow and capacity to take away the waste heat of the core, ensuring that the main circuit has a certain flow rate is the most critical factor. Only by improving the natural circulation capacity can the reactor core under loss of flow accident be enhanced. The residual heat removal capacity, especially the cooling capacity of the core. [0003] Usually the means to a...

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Problems solved by technology

[0004] (1) The main pump with stronger idling is adopted, so that the main pump can rely on inertia to achieve longer operation after losing power, so that the rate of slowing down of the flow rate becomes lower, but it can only increase the flow rate in the first few tens of seconds , cannot play a role in long-term cooling;

[0005] (2) Use a large core grid pitch to reduce the total pressure drop of the reactor, but this method often means that the neutron leakage of the core increases, and the price of increasing the fuel loading of the core must be paid;

[0006] (3) Use a higher heat exchanger-core height difference, which can increase the pressure head of natural circulation, that is, the driving force. However, increasing the height difference means that the reactor must be built higher, which will undoubtedly directly damage the reactor economy, and at the same time, for liquid metal cooling reactors, it may also affect the seismic performance of the reactor body

[0007] But so far, there is no system and method that can actively improve the natural circulation when the waste heat is discharged

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