Spent fuel water tank natural ventilation and water recovery system responding to serious accident

Abstract

The invention belongs to design of a fuel building ventilating system for a nuclear power station and in particular relates to a spent fuel water tank natural ventilation and water recovery system responding to a serious accident. The structure of the system comprises a metal dome which is taken as one part of roof of a fuel building, wherein the metal dome is provided with a plurality of ventilation channels in circumferential direction; a natural ventilation chimney is arranged above the ventilation channels; the inlet of each ventilation channel is arranged above a spent fuel water tank; and the outlet of each ventilation channel is connected with a water receiver. According to the invention, the natural ventilation on a building in which the spent fuel water tank is located under the serious accident condition and discharge of decay heat of partial spent fuel are realized by multiple ventilation channels on the roof of the fuel building, thus the fuel building is prevented from being overheated and overpressured and hydrogen is prevented from gathering; and isolating, triggering and main functions of the spent fuel water tank natural ventilation and water recovery system disclosed by the invention are not dependent on exterior power input, thus the spent fuel water tank natural ventilation and water recovery system disclosed by the invention has non-active characteristic and high reliability.

Description

technical field [0001] The invention belongs to the design of the ventilation system of a nuclear power plant fuel building, and in particular relates to a natural ventilation and water recovery system for spent fuel pools for serious accidents. Background technique [0002] For the second-generation (M310) and third-generation (AP1000) nuclear power units, the design of the existing spent fuel pool ventilation system (nuclear fuel plant ventilation system) mainly considers three aspects: 1. To ensure the safe and normal operation of relevant equipment and personnel in the fuel plant Enter the required indoor temperature; 2. Limit the water vapor content in the indoor ambient air of the fuel plant to reduce the risk of condensation on the wall of the fuel pool; 3. In the event of fuel loading and unloading accidents, lead tank loading and unloading accidents, and LOCA accidents, reduce Remove airborne radioactivity to acceptable levels. It can be seen that the design of the...

AI Technical Summary

Problems solved by technology

Under accident conditions, the boiling of the spent fuel pool and the lack of ventilation in the building will bring many adverse consequences: first, the steam generated by the boiling of the spent fuel pool will fill the entire fuel building, and then pass through the pressure boundaries of various places as the pressure of the building increases. Unpredictable spills occur, and these vapors will eventually condense everywhere in the nuclear island to cause cross-radiation contamination; secondly, the condensed water that overflows, condenses, and spreads around the nuclear island cannot usually be recycled; in addition, as As the accident progresses, once the fuel assembly melts down and hydrogen is released, the fuel plant that is relatively closed but has no hydrogen elimination facilities is very likely to have hydrogen accumulation, followed by a hydrogen explosion

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