Abstract: A compact nuclear power generation system includes a reactor (3) comprising a core (2) which uses metal fuel containing either or both of uranium-235/238 and plutonium-239. A reactor vessel (1) houses the core (2). Metal sodium primary coolant (8) is heated by the core (2). A neutron reflector (9) maintains the effective multiplication factor of neutrons emitted from the core (2) at approximately one or more to bring the core into a critical state. The neutron reflector is movable from a lower part towards an upper part of the core. The heated metal sodium is supplied to a main heat exchanger (15) which is located outside the reactor. A secondary coolant of supercritical carbon dioxide, which circulates through the main heat exchanger, is in heat exchange with the heated metal sodium. The heated secondary coolant drives a turbine (20). A power generator (21) can be operated by the driven turbine.

Abstract: [Problem] To build a secure and high-efficiency power generation system while achieving a further reduction in the size of the entire system. [Solution] A compact nuclear power generation system is provided with a reactor (3) comprising a core (2) which uses metal fuel containing either or both of uranium-235/238 and plutonium-239, a reactor vessel (1) which houses the core (2), metal sodium which is filled into the reactor vessel (1) and heated by the core (2), and a neutron reflector (9) which maintains the effective multiplication factor of neutrons emitted from the core (2) at approximately one or more to bring the core into a critical state. A main heat exchanger (15) is installed outside the reactor (3). The metal sodium heated by the reactor (3) is supplied to the main heat exchanger (15), and supercritical carbon dioxide that is subjected to heat exchange with the heated metal sodium circulates therethrough.

Abstract: A nuclear reactor in which a secondary or tertiary coolant system of a nuclear steam supply system is simplified, comprising: a reactor vessel (2) which integrates a reactor core (1); a first coolant (3) which is stored in the reactor vessel (2) and heated by the reactor core (1) to convect; a first heat transfer tube (4) which is arranged in the reactor vessel (2) and comes into contact with the first coolant (3); and a second coolant (5) which is supplied from the outside of the reactor vessel (2) to the first heat transfer tube (4), cools the first coolant (3) and led to the outside of the reactor vessel (2).

Abstract: A nuclear reactor in which a secondary or tertiary coolant system of a nuclear steam supply system is simplified, comprising: a reactor vessel (2) which integrates a reactor core (1); a first coolant (3) which is stored in the reactor vessel (2) and heated by the reactor core (1) to convect; a first heat transfer tube (4) which is arranged in the reactor vessel (2) and comes into contact with the first coolant (3); and a second coolant (5) which is supplied from the outside of the reactor vessel (2) to the first heat transfer tube (4), cools the first coolant (3) and led to the outside of the reactor vessel (2).

Abstract: A fast reactor comprises a core composed of nuclear fuel, a core barrel surrounding an outer periphery of the core, an annular reflector surrounding an outer periphery of the core barrel, a partition wall structure surrounding an outer periphery of the annular reflector and supporting the core barrel by a supporting structure arranged radially of the fast reactor, the partition wall structure constituting an inner wall of a coolant passage for a primary coolant, a neutron shield surrounding an outer periphery of the partition wall structure and disposed in the coolant passage, a reactor vessel surrounding an outer periphery of the neutron shield and having an inner wall constituting an outer wall of the coolant passage, and a guard vessel surrounding an outer periphery of the reactor vessel.

Abstract: A double tank type fast breeder reactor including a reactor vessel, and a tank of a secondary cooling system located outside the reactor vessel. The reactor vessel contains a core and installations of a primary cooling system, and the tank contains circulation pumps of the secondary cooling system and steam generators alternately located in the tank, and a body of sodium serving as a secondary coolant located at outer peripheries of the circulation pumps and steam generators. The tank includes an annular portion defined in the tank between walls of the tank and reactor vessel serving as a path of circulation of the secondary coolant.