A double-layer crucible core melt collection device with internal cooling pipes

Abstract

The invention belongs to the technical field of nuclear safety control, and relates to a double-layer crucible core melt collecting device with internal cooling pipes. The trapping device includes a reactor pressure vessel, an inner crucible, an outer crucible, a cooling flow channel, a pile pit, a pile cavity, a cooling pipe, and a water inlet of the cooling pipe. The inner crucible is arranged directly below the reactor pressure vessel, and is fixed In the outer crucible outside and below the reactor pressure vessel, a cooling flow channel for cooling water flow is formed between the inner crucible and the outer crucible, and the outer crucible is installed in the pile pit cavity formed inside the pile pit; the inner crucible There are multiple cooling pipes inside, and each cooling pipe communicates with the cooling flow channel through the cooling pipe water inlet at the bottom. There are small holes on the side walls of some cooling pipes and the outside is covered with a 5-30mm thick sacrificial concrete protective layer . Utilizing the trapping device of the invention can remarkably improve the retention success rate and cooling efficiency of the core trap for the core melt.

Description

technical field [0001] The invention belongs to the technical field of nuclear safety control, and relates to a double-layer crucible core melt collecting device with internal cooling pipes. Background technique [0002] After the serious accidents at the Three Mile Island and Chernobyl nuclear power plants, the nuclear power industry began to focus on research and research on the prevention and mitigation of severe accidents. Due to engineering and other requirements. [0003] When a serious accident occurs in a pressurized water reactor nuclear power plant, the loss of core waste heat removal means will evaporate and exhaust the coolant, the core will be exposed and continue to heat up, the fuel elements will melt due to the loss of cooling, and the core melt will fall into the reactor pressure vessel (RPV) lower chamber, which in turn causes the failure of the lower head of the reactor pressure vessel. If effective measures cannot be taken to cool it, the core melt may m...

AI Technical Summary

Problems solved by technology

[0003] When a serious accident occurs in a pressurized water reactor nuclear power plant, the loss of core waste heat removal means will evaporate and exhaust the coolant, the core will be exposed and continue to heat up, the fuel elements will melt due to the loss of cooling, and the core melt will fall into the reactor pressure vessel (RPV) lower chamber, which in turn causes the failure of the lower head of the reactor pressure vessel. If effective measures cannot be taken to cool it, the core melt may melt through the pressure vessel

After the pressure vessel melts through, the core melt is sprayed directly onto the containment raft foundation to interact with structural concrete (MCCI), and gradually erodes the containment raft foundation downward at a relatively fast speed within a certain period of time. If the thickness of the raft foundation is insufficient , the bottom plate may be melted through and cause the integrity of the containment to be destroyed

The radioactive material will then go directly into the soil, causing serious environmental impacts

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