Abstract: Provided is a nuclear reactor having a load following control system in which a nuclear reaction therein is naturally controlled by the generated heat, the nuclear reactor being provided with: a reactor core provided with a plurality of fuel assemblies of metallic fuels containing uranium (U) 235, 238 and/or plutonium (Pu) 239; a primary coolant comprising a liquid metal; a neutron reflector which serves to control the nuclear reaction in the reactor core and is disposed to enclose the periphery of the reactor core; and a mechanism which contains a-liquid or a gas having a thermal expansion coefficient greater than that of the neutron reflector, and converts the coefficient of volumetric expansion into an amount of linear thermal expansion, and, by using same, moves the neutron reflector or adjusts the spacing between the plurality of fuel assemblies.

Abstract: A nuclear power generation system being safe and easily controlled by load following. The nuclear power generation system has a nuclear reactor employing a load following control method. The reactor includes: a fuel assembly reactor core having metallic fuel containing at least one selected from uranium-235, uranium-238 and plutonium-239; a reactor vessel containing the reactor core; metallic sodium loaded into the reactor vessel and heated by the reactor core; and a neutron reflector for achieving criticality in the reactor core with effective multiplication factor of neutrons emitted from the reactor core being maintained at or above about 1. The neutron reflector is coupled to spring or spiral metallic members and utilizing heat deformation in the metallic members due to the temperature in coolant metallic sodium to control the fast neutron reflection efficiency of the neutron reflector.

Abstract: Engineering safety systems always have insufficiencies in terms of safety, and construction of a complete safety system causes installation costs for the safety system to become very high.

Abstract: A molten salt electrolysis tank, comprises: an anode feeder which is equipped with a mechanism for recovering deteriorated contact resistance that takes place between the metal fuel rod and the anode in the course of the anodic electrolysis; a cathode feeder which is controlled so as to have a potential in a range that causes U and/or Pu ions to be reduced to metal; a heating mechanism for locally heating the metal fuel rod and/or an excitation mechanism for bringing the metal fuel rod into a locally excited state; and a solenoid coil or a permanent magnet that is disposed between the anode feeder and the cathode feeder so as to improve separation efficiency of U and/or Pu ions by applying a combination of an electric field and a magnetic field.

Abstract: Provided is a nuclear reactor system and method therefor, for increasing the speed of conversion of a radionuclide to a stable nuclide to reduce radionuclide concentration using thermal neutrons produced by reducing the velocity of fast neutrons, while simultaneously subjecting fast-neutron-induced thermal energy of a primary cooling material to heat exchange with a secondary cooling material in a heat exchanger (7), and feeding the energy to a turbine system to generate power, the system having a nuclear reactor container (1) comprising a first container (11), and a second container (12), a plurality of metal fuel assemblies (22) and a liquid metal, which is the primary cooling material, being disposed in the first container, and the second cooling material capable of dual use as a neutron moderator and a MA radioactivity-extinguishing assembly or FP-extinguishing assembly (24) being loaded in the second container.

Abstract: Provided is a nuclear reactor system and method therefor, for increasing the speed of conversion of a radionuclide to a stable nuclide to reduce radionuclide concentration using thermal neutrons produced by reducing the velocity of fast neutrons, while simultaneously subjecting fast-neutron-induced thermal energy of a primary cooling material to heat exchange with a secondary cooling material in a heat exchanger (7), and feeding the energy to a turbine system to generate power, the system having a nuclear reactor container (1) comprising a first container (11), and a second container (12), a plurality of metal fuel assemblies (22) and a liquid metal, which is the primary cooling material, being disposed in the first container, and the second cooling material capable of dual use as a neutron moderator and a MA radioactivity-extinguishing assembly or FP-extinguishing assembly (24) being loaded in the second container.

Abstract: To provide a geothermal heat exchanger with high thermal efficiency, which can reduce heat loss to a non-geothermal zone when high-temperature liquid heated in the deep underground is transported to the ground. The geothermal heat exchanger of the present invention includes a liquid transport pipe provided with a liquid lowering pipe to which a heat exchange liquid which is pressurized and supplied, a liquid raising pipe which is disposed on the inside or outside side of the liquid lowering pipe and raises the heat exchange liquid which is descended to the geothermal zone, moved from the lower part and composed of the high-temperature liquid generated by which heat from the geothermal zone is supplied, and an outer thermal insulation layer which is provided on a part or the whole of the outside of the liquid transport pipe at least from the ground surface to the geothermal zone.

Abstract: A molten salt electrolysis tank, comprises: an anode feeder which is equipped with a mechanism for recovering deteriorated contact resistance that takes place between the metal fuel rod and the anode in the course of the anodic electrolysis; a cathode feeder which is controlled so as to have a potential in a range that causes U and/or Pu ions to be reduced to metal; a heating mechanism for locally heating the metal fuel rod and/or an excitation mechanism for bringing the metal fuel rod into a locally excited state; and a solenoid coil or a permanent magnet that is disposed between the anode feeder and the cathode feeder so as to improve separation efficiency of U and/or Pu ions by applying a combination of an electric field and a magnetic field.

Abstract: To provide a geothermal heat exchanger with high thermal efficiency, which can reduce heat loss to a non-geothermal zone when high-temperature liquid heated in the deep underground is transported to the ground. The geothermal heat exchanger of the present invention includes a liquid transport pipe provided with a liquid lowering pipe to which a heat exchange liquid which is pressurized and supplied, a liquid raising pipe which is disposed on the inside or outside side of the liquid lowering pipe and raises the heat exchange liquid which is descended to the geothermal zone, moved from the lower part and composed of the high-temperature liquid generated by which heat from the geothermal zone is supplied, and an outer thermal insulation layer which is provided on a part or the whole of the outside of the liquid transport pipe at least from the ground surface to the geothermal zone.

Abstract: The present invention provides a small nuclear power generation system being safe and easily controlled by load following, and allowing reductions in manufacturing costs and maintenance and management costs. The small nuclear power generation system has a small nuclear reactor employing a load following control method. The reactor includes: a fuel assembly reactor core 4 having metallic fuel containing one or both of uranium (235, 238) and plutonium-239; a reactor vessel 1 containing the fuel assembly reactor core 4; metallic sodium loaded into the reactor vessel 1 and heated by the fuel assembly reactor core 4; and a neutron reflector 2 for achieving criticality in the reactor core with effective multiplication factor of neutrons emitted from the fuel assembly reactor core 4 being maintained at or above about 1.