A nuclear reactor is categorized into a loop type reactor where main components (a steam generator, a pressurizer, a pump impeller, etc.) are installed outside a reactor vessel (e.g., a commercial reactor: Korea), and an integral reactor where main components are installed inside a reactor vessel (e.g., SMART: Korea) according to an installation position of the main components.
Further, the nuclear reactor is categorized into an active reactor (e.g., a commercial reactor: Korea) and a passive reactor (e.g., AP1000: USA) according to an implementation method of a safety system. The active reactor means a reactor using an active device such as a pump which is operated by power generated from an emergency diesel generator, etc. in order to operate a safety system. And the passive reactor means a reactor using a passive device which is operated by a passive power such as a gravitational force or a gas pressure, in order to operate a safety system.
A reactor coolant pump for circulating a fluid inside a reactor coolant system is installed at a nuclear reactor. However, since the conventional reactor coolant pump uses an electric motor, and electric power for driving the electric motor is required. In a nuclear power plant, electric power is generated by a turbine and an electric generator. In this case, a large energy loss (about 60%) occurs while electricity is generated. Further, since an electric motor is used, an installation space of the electric motor is required, a sealing facility for preventing current leakage should be maintained, and equipment for cooling heat generated from the electric motor is required. This may cause the reactor coolant pump to be designed and fabricated with a difficulty, and may cause increased costs, etc.
Thus, a reactor coolant pump capable of overcoming problems of the conventional reactor coolant pump using an electric motor, may be considered.