초록 ▼

Control rods are inserted into the core of a nuclear reactor in operation to shut down the reactor output. Before completion of entire control rod insertion, a high-temperature coolant flowing in piping for a reactor water clean-up system is sprayed into the space in the upper portion of the reactor

Control rods are inserted into the core of a nuclear reactor in operation to shut down the reactor output. Before completion of entire control rod insertion, a high-temperature coolant flowing in piping for a reactor water clean-up system is sprayed into the space in the upper portion of the reactor vessel. As the space is under negative pressure, oxygen existing in the water droplets of the sprayed coolant is separated. After completion of entire control rod insertion, a residual heat removal system is operated. The spraying operation is discontinued and a low-temperature coolant cooled by a heat exchanger in the residual heat removal system is sprayed into said space. The coolant sprayed by said first spraying operation is not cooled by the heat exchanger in said residual heat removal system.

대표청구항 ▼

A system for degassing a nuclear reactor comprising a nuclear reactor vessel containing a coolant with a concentration of gas therein, the coolant being in a hot temperature state during operation of the nuclear reactor, means for recirculating the coolant in the reactor vessel, means for extracting

A system for degassing a nuclear reactor comprising a nuclear reactor vessel containing a coolant with a concentration of gas therein, the coolant being in a hot temperature state during operation of the nuclear reactor, means for recirculating the coolant in the reactor vessel, means for extracting at least part of the coolant in the recirculating means, means for spraying the extracted coolant during shutdown when the coolant temperature is in at least a range between 130°C. and 100°C. into a space of the nuclear reactor vessel for separating the gas from the coolant, and means for extracting the gas in the space of the nuclear reactor vessel so as to degasify the nuclear reactor vessel for preventing stress corrosion cracking of the nuclear reactor vessel and associated equipment.