Pressurized water reactor nuclear power plant circuit accident gas exhaust system

The invention belongs to a pressurized water reactor nuclear power plant accident treatment, and particularly to a pressurized water reactor nuclear power plant circuit accident gas exhaust system, which comprises an accident gas exhaust valve connected between a reactor pressure vessel and a normal gas exhaust valve, wherein the accident gas exhaust valve is divided into two series, is led out from the top of the reactor pressure vessel, passes through two normally closed series connected in parallel, is connected into a pressurizer safety valve exhaust pipeline in a parallel manner, and enters a pressure-relief box, wherein the first normally closed electromagnetic valve and the second normally closed electromagnetic valve form the series A, and the third normally closed electromagnetic valve and the fourth normally closed electromagnetic valve form the series B. The pressurized water reactor nuclear power plant circuit accident gas exhaust system has the following advantage that: the system adopts the electromagnetic valves, has characteristics of stable and reliable performance and quick action, and can be provided for effectively alleviating the severe accident consequence and ensuring the integrity of the reactor pressure vessel under the severe accident.