Large-scale passive nuclear plant reactor core catcher with bottom water injection and external cooling

Abstract

The invention provides a large-scale passive nuclear plant reactor core catcher with bottom water injection and external cooling. The catcher comprises a reactor cavity coating the lower middle part of a reactor pressure vessel, and a reactor cavity concrete soleplate is formed at the bottom of the reactor cavity; a refractory layer is formed on the side surface of the reactor cavity and the bottom of the reactor cavity concrete soleplate; a steel cylinder is sleeved outside the refractory layer; an external cooling passage is formed at the bottom of the steel cylinder, and a cooling passage inlet and a cooling passage outlet are respectively formed at the two outward-extending ends of the external cooling passage; and dozens of nozzles are fixed at the bottom of the steel cylinder, and the upper ends of the nozzles extend into the reactor cavity concrete soleplate while the lower ends of the nozzles extend into the external cooling passage. According to the invention, the dilution and the temperature reduction of a melt are implemented through the melting of concrete by adopting the reactor cavity concrete soleplate as a sacrificial material. A reactor core melt is collected in the refractory layer after the reactor cavity concrete soleplate is molten through, so that the security and the reliability of a nuclear plant are further improved.

Description

technical field [0001] The invention relates to a core catcher of a large-scale passive pressurized water reactor nuclear power plant, in particular to a design that adopts bottom water injection and external passive cooling to further improve the safety of the nuclear power plant. Background technique [0002] The use of the core trap technology can make the molten material from the pressure vessel effectively stay in a certain device, and the interaction between the core molten material and the concrete can be effectively prevented by adopting the corresponding external cooling technology of the molten material, thereby Reduce the risk of melting through the bottom of the containment vessel, significantly reduce the release of fission products to the environment, and greatly reduce the radioactive consequences of severe accidents. [0003] In the design of existing passive PWR nuclear power plants, many severe accident mitigation strategies have been adopted. For example,...

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Problems solved by technology

Therefore, the IVR also has the risk of failure. After the IVR fails, the core melt will be released from the pressure vessel to the reactor cavity. If there is a large amount of water in the reactor cavity, a steam explosion will occur, and the interaction between the core melt and concrete will also be It is very likely that a large amount of radioactive substances will be released into the environment

Moreover, as the power of passive PWR nuclear power plants continues to increase, the probability of successful IVR will also decrease

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