An operating floor confinement has an operating floor, a sidewall that surrounds the operating floor, a ceiling that is provided on an upper portion of the sidewall, a reactor well, a fuel pool, a dryer and separator pit, an equipment hatch that is provided on the sidewall, an air lock that is provided on the sidewall, and an isolation valve that is provided in a penetration line. The operating floor confinement forms a pressure boundary having pressure resistance and a leakage protection function. The operating floor confinement is separated from an equipment area of the reactor building and has no blowout panel.

A sample container, sampling system and operating methods permit representative sampling from a liquid phase or boiling liquid, a gaseous phase, a containment sump, containment atmosphere, or condensation chamber of a nuclear power plant following a severe accident. A sample container obtaining an environmental sample includes an outer chamber surrounded by an outer container wall, being directly fluidically connected to the environment through a passage opening in the outer container wall and being fillable with a liquid at least in a base region. An inner chamber surrounded by an inner container wall is fluidically connected to the base region through a passage opening in the inner container wall, has connections for sampling and conveyor medium lines and is otherwise pressure and media tightly sealed from the environment. A pneumatically or hydraulically actuatable closure device for the passage opening between the outer and inner chambers has an actuation medium line connection.

An environmentally sequestered nuclear spent fuel pool in one embodiment includes sidewalls and a base slab that confine a water impoundment. The pool includes fuel racks containing spent fuel assemblies which heat the water via radioactive decay. A dual liner system enclosing the pool forms an impervious barrier providing redundant provisions for preventing leakage of contaminated pool water into the environment. An interstitial space is formed between the liners which may be maintained at sub-atmospheric pressures by a vacuum pump system that evacuates the space. By maintaining the pressure in the space at a negative pressure with corresponding boiling point less than the temperature of the pool water, any leakage through the inner-most liner into the interstitial space will vaporize and be extracted via the pump for signaling a potential leak in the liner system.

An environmentally sequestered nuclear spent fuel pool in one embodiment includes sidewalls and a base slab that confine a water impoundment. The pool includes fuel racks containing spent fuel assemblies which heat the water via radioactive decay. A dual liner system enclosing the pool forms an impervious barrier providing redundant provisions for preventing leakage of contaminated pool water into the environment. An interstitial space is formed between the liners which may be maintained at sub-atmospheric pressures by a vacuum pump system that evacuates the space. By maintaining the pressure in the space at a negative pressure with corresponding boiling point less than the temperature of the pool water, any leakage through the inner-most liner into the interstitial space will vaporize and be extracted via the pump for signaling a potential leak in the liner system.

A nuclear reactor includes a nuclear reactor core comprising fissile material disposed in a reactor pressure vessel having vessel penetrations that exclusively carry flow into the nuclear reactor and at least one vessel penetration that carries flow out of the nuclear reactor. An integral isolation valve (IIV) system includes passive IIVs each comprising a check valve built into a forged flange and not including an actuator, and one or more active IIVs each comprising an active valve built into a forged flange and including an actuator. Each vessel penetration exclusively carrying flow into the nuclear reactor is protected by a passive IIV whose forged flange is directly connected to the vessel penetration. Each vessel penetration carrying flow out of the nuclear reactor is protected by an active IIV whose forged flange is directly connected to the vessel penetration. Each active valve may be a normally closed valve.

The present invention relates to an integrated nuclear reactor system including a double containment structure using liquid nitrogen, the nuclear reactor system comprising: a reactor vessel; a reactor core disposed in the reactor vessel; a steam generator disposed in the reactor vessel and located above the reactor core; a first containment vessel surrounding the reactor vessel with a first space interposed therebetween; a second containment vessel surrounding the first containment vessel with a second space interposed therebetween; and a liquid nitrogen supply unit supplying liquid nitrogen into the second space.

The present invention relates to an integrated nuclear reactor system including a double containment structure using liquid nitrogen, the nuclear reactor system comprising: a reactor vessel; a reactor core disposed in the reactor vessel; a steam generator disposed in the reactor vessel and located above the reactor core; a first containment vessel surrounding the reactor vessel with a first space interposed therebetween; a second containment vessel surrounding the first containment vessel with a second space interposed therebetween; and a liquid nitrogen supply unit supplying liquid nitrogen into the second space.

A system for confining and cooling melt from the core of a nuclear reactor comprises a guide device, a cantilever truss, a filler for receiving and distributing melt. The filler being disposed in a housing having water supply valves mounted around its perimeter and having a flange with a thermal shield mounted thereon. A drum is mounted on the flange and comprises reinforcing ribs mounted bearing against a cover and a bottom. The drum comprises tensioning elements connecting the drum, via a support flange, to the flange of the housing, and spacing elements. The drum comprises nozzles having water supply valves mounted therein with sealed covers, and hydraulic dampers connected to external sources of water and to the water supply valves by feed pipes, pressure pipes, compensating pipes and equalizing pipes, for increasing the reliability of the system for confining and cooling melt from the core of a nuclear reactor.

A system for confining and cooling melt from the core of a nuclear reactor comprises a guide device, a cantilever truss, a filler for receiving and distributing melt. The filler being disposed in a housing having water supply valves mounted around its perimeter and having a flange with a thermal shield mounted thereon. A drum is mounted on the flange and comprises reinforcing ribs mounted bearing against a cover and a bottom. The drum comprises tensioning elements connecting the drum, via a support flange, to the flange of the housing, and spacing elements. The drum comprises nozzles having water supply valves mounted therein with sealed covers, and hydraulic dampers connected to external sources of water and to the water supply valves by feed pipes, pressure pipes, compensating pipes and equalizing pipes, for increasing the reliability of the system for confining and cooling melt from the core of a nuclear reactor.

Molten salt nuclear fission reactor including a core through which a fuel salt flows, a unit for circulating the fuel salt, a primary heat exchanger through which a heat-transfer salt flows, a primary enclosure which is impermeable to liquid salts and contains the reactor core, and a shelter. The reactor includes a parallelepiped matrix including alternating layers of fuel salt channels, and layers of heat-transfer salt channels. The matrix forms both the reactor core, in which the fission occurs, and the primary heat exchanger of the reactor. The circulating unit is entirely located within the primary enclosure and are configured to extract the fuel salt from one portion of the fuel salt channels on one side of the matrix and to propel the fuel salt into the other portion of the channels on the same side of the matrix.