A core melt trap with internal cooling capability

Abstract

The invention relates to designing technology of reactor safety systems, specifically to a molten core catcher with interior cooling capacity. The molten core catcher comprises a melt retaining container arranged in a vertical shaft vertically connected with the bottom of a reactor pit, a plurality of interior tube bundles arranged in the melt retaining container and used for injecting a coolant and a sacrificial material arranged in the outer tube walls of the interior tube bundles and in the melt retaining container. Under a working condition of a serious accident, the molten core catcher provided by the invention can realize maximization of removal of the heat of melts by exchanging heat through the tube bundles distributed in the molten core catcher and injecting cooling water formed by later burning-up of the interior tube bundles for cooling, so long-term security of a nuclear power plant after the serious accident is guaranteed.

Description

technical field [0001] The invention relates to the reactor safety system design technology, in particular to a core melt catcher with internal cooling capability. Background technique [0002] The ultimate goal of nuclear power plant safety design is to prevent large-scale leakage of radioactivity, and three barriers are set up for this purpose: fuel cladding, primary circuit pressure boundary and containment vessel. In the event of an accident, if the core fuel elements cannot be cooled quickly and effectively to take away the decay heat, the residual heat of the core will cause the coolant to evaporate and be exhausted, the core will be exposed, the fuel elements will continue to heat up, and finally the fuel cladding will melt (The accident developed into a serious accident at this time), and then the relevant reactor internals were melted and fell into the lower head of the reactor pressure vessel (RPV) to form a molten pool of core melt. If effective measures cannot b...

AI Technical Summary

Problems solved by technology

[0008] The core catcher applied to EPR requires a larger expansion chamber, and the melt migration path is longer and has many links; the core catcher applied to WWER1000 needs at least 10 months to recover after the melt is retained. The melt is finally cooled; the core catcher designed by the COMET concept is currently only able to deal with the melt with a small thickness

In addition, none of the above-mentioned technologies related to the core catcher considers the internal cooling of the melt to maximize heat transfer from the melt

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