A long-term passive containment heat extraction system

Abstract

The invention aims to provide a heat derivation system for a long-term passive containment. The system mainly comprises a cooling water box (6), separating valves (5 and 6), an internal heat exchanger (1) and an external air cooling condenser-cooler (7), wherein the internal heat exchanger and the external air cooling condenser-cooler both adopt high-efficiency enhanced heat transfer pipes to improve the heat transfer efficiency and reduce the size of the heat exchanger; steam guide plates used for guiding the flow direction of internal airflow and protecting devices and pipelines are arranged inside an internal concrete containment. When accidents, such as LOCA and MSLB, happen, the system can provide long-term and efficient cooling for the containment without external power; temperature and pressure inside the reactor containment are always maintained under the permissible limit under a condition that human intervention and other external cooling measures are eliminated, so that integrity of the containment is maintained.

Description

technical field [0001] The invention relates to a containment vessel in the field of nuclear safety and thermal hydraulic technology, in particular to a heat derivation system of the containment vessel. Background technique [0002] The containment is the last safety barrier to prevent the leakage of radioactive materials in the event of an accident in a nuclear power plant. In the event of serious accidents such as LOCA and MSLB, the containment heat export system must ensure that the temperature and pressure in the containment do not exceed the design allowable range, so as to maintain the integrity of the containment. [0003] At present, the passive containment heat export system of the PWR nuclear power plant proposed by AP1000 in the United States is mainly designed for the steel-concrete containment. This scheme requires a gravity water injection tank to be installed above the containment vessel, and the steel containment vessel is used as the accident isolation boun...

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Problems solved by technology

[0004] It can be seen that there is a major problem in the design of the above-mentioned containment heat export system including AP1000, that is, it can only ensure that the temperature and pressure of the containment do not exceed the design reference within a certain period of time, and the maximum cooling time is 72 Hours, beyond this time limit, the system will fail because the water in the water tank is exhausted

After 72 hours, it is necessary to rely on external power to refill the water tank to make the system function again. To extend the cooling time without human intervention, it can only be achieved by further increasing the volume of the water tank, but the increase in the volume of the water tank It will also greatly increase the impact of earthquakes

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