VENT DEVICE FOR TOP OF REACTOR PRESSURE VESSEL

摘要

PROBLEM TO BE SOLVED: To provide a vent device for a top of a reactor pressure vessel which enables highly reliable safe operation by effectively and surely preventing accumulation of a non-condensible gas around the top of the reactor pressure vessel. SOLUTION: The vent device 20 for the top of the reactor pressure vessel comprises a head spray system 31 of the reactor pressure vessel for feeding cooling water to a head spray nozzle 36 of the reactor pressure vessel disposed in an upper part of the reactor pressure vessel 22 and a vent system 30 of the reactor pressure vessel for guiding the non-condensible gas produced during operation of a reactor to a main steam pipe. The head spray system 31 of the reactor pressure vessel is provided with a branch vent system 32 branched from a reactor pressure vessel 22 side of a check valve 39 provided on a head spray pipe 38 of the reactor pressure vessel. The branch vent system 32 is provided with a vent branch pipe 40 branched from the head spray pipe 38 of the reactor pressure vessel. The vent branch pipe 40 has a downstream side thereof connected to a vent pipe 33 of the system 30 and an orifice 41 provided halfway of the vent branch pipe 40. COPYRIGHT: (C)2004,JPO