Apparatuses for reducing or eliminating Type 1 LOCAs in a nuclear reactor vessel. A nuclear reactor including a nuclear reactor core comprising a fissile material, a pressure vessel containing the nuclear reactor core immersed in primary coolant disposed in the pressure vessel, and an isolation valve assembly including, an isolation valve vessel having a single open end with a flange, a spool piece having a first flange secured to a wall of the pressure vessel and a second flange secured to the flange of the isolation valve vessel, a fluid flow line passing through the spool piece to conduct fluid flow into or out of the first flange wherein a portion of the fluid flow line is disposed in the isolation valve vessel, and at least one valve disposed in the isolation valve vessel and operatively connected with the fluid flow line.

Apparatuses for reducing or eliminating Type 1 LOCAs in a nuclear reactor vessel. A nuclear reactor including a nuclear reactor core comprising a fissile material, a pressure vessel containing the nuclear reactor core immersed in primary coolant disposed in the pressure vessel, and an isolation valve assembly including, an isolation valve vessel having a single open end with a flange, a spool piece having a first flange secured to a wall of the pressure vessel and a second flange secured to the flange of the isolation valve vessel, a fluid flow line passing through the spool piece to conduct fluid flow into or out of the first flange wherein a portion of the fluid flow line is disposed in the isolation valve vessel, and at least one valve disposed in the isolation valve vessel and operatively connected with the fluid flow line.

Systems in the field of nuclear energy, in particular, systems that ensure the safety of nuclear power plants (NPP), and can be used in severe accidents that lead to reactor pressure vessel and its containment destruction. In one aspect, the system can increase the safety of a nuclear power plant by excluding the release of liquid and solid radioactive materials (corium) outside the device to confine core melt in the event of a severe accident with core melt discharge out of the nuclear reactor. In a second aspect, the efficiency and reliability of the device for confining core melt can be improved by improving the corium cooling conditions. This can be achieved by the use of filler formed in upper and lower cassettes having vertical and horizontal channels that ensure uniform distribution of the melt in the cooled body.

Systems in the field of nuclear energy, in particular, systems that ensure the safety of nuclear power plants (NPP), and can be used in severe accidents that lead to reactor pressure vessel and its containment destruction. In one aspect, the system can increase the safety of a nuclear power plant by excluding the release of liquid and solid radioactive materials (corium) outside the device to confine core melt in the event of a severe accident with core melt discharge out of the nuclear reactor. In a second aspect, the efficiency and reliability of the device for confining core melt can be improved by improving the corium cooling conditions. This can be achieved by the use of filler formed in upper and lower cassettes having vertical and horizontal channels that ensure uniform distribution of the melt in the cooled body.

Nuclear power plant (NPP) containment building separation system dividing the NPP containment building into isolated containment building rooms. The system includes containment building separation shutters located in the circular gap which divides the containment building rooms and the containment building walls; an air supply unit connected to a manifold ring which, in turn, is connected to the air-inflated shutters designed to ensure insulation of the airspace inside the containment building rooms when inflated and to connect the airspace when deflated. In emergency mode the air supply to the air-inflated shutters is terminated, and the shutters get deflated and fully open the circular gap which ensures convection process throughout the whole area of containment building.

Nuclear power plant (NPP) containment building separation system dividing the NPP containment building into isolated containment building rooms. The system includes containment building separation shutters located in the circular gap which divides the containment building rooms and the containment building walls; an air supply unit connected to a manifold ring which, in turn, is connected to the air-inflated shutters designed to ensure insulation of the airspace inside the containment building rooms when inflated and to connect the airspace when deflated. In emergency mode the air supply to the air-inflated shutters is terminated, and the shutters get deflated and fully open the circular gap which ensures convection process throughout the whole area of containment building.

Apparatuses for reducing or eliminating Type 1 LOCAs in a nuclear reactor vessel. A nuclear reactor including a nuclear reactor core comprising a fissile material, a pressure vessel containing the nuclear reactor core immersed in primary coolant disposed in the pressure vessel, and an isolation valve assembly including, an isolation valve vessel having a single open end with a flange, a spool piece having a first flange secured to a wall of the pressure vessel and a second flange secured to the flange of the isolation valve vessel, a fluid flow line passing through the spool piece to conduct fluid flow into or out of the first flange wherein a portion of the fluid flow line is disposed in the isolation valve vessel, and at least one valve disposed in the isolation valve vessel and operatively connected with the fluid flow line.

Apparatuses for reducing or eliminating Type 1 LOCAs in a nuclear reactor vessel. A nuclear reactor including a nuclear reactor core comprising a fissile material, a pressure vessel containing the nuclear reactor core immersed in primary coolant disposed in the pressure vessel, and an isolation valve assembly including, an isolation valve vessel having a single open end with a flange, a spool piece having a first flange secured to a wall of the pressure vessel and a second flange secured to the flange of the isolation valve vessel, a fluid flow line passing through the spool piece to conduct fluid flow into or out of the first flange wherein a portion of the fluid flow line is disposed in the isolation valve vessel, and at least one valve disposed in the isolation valve vessel and operatively connected with the fluid flow line.

System for confining and cooling melt from the core of a water-moderated nuclear reactor comprising a melt trap. The melt trap is installed in the reactor vessel bottom and provided with a cooled containment, consisting of outer and inner housings between which there is a sealant, and the filler for the melt dilution placed in the melt trap inner body. The melt trap inner body has a damper consisting of a central mantle, bearing ribs connected with the central mantle, titled plates, placed between the bearing ribs, the stops providing fastening of the damper to the melt trap body.

An integrated passive cooling containment structure for a nuclear reactor includes a concentric arrangement of an inner steel cylindrical shell and an outer steel cylindrical shell that define both a lateral boundary of a containment environment of the nuclear reactor that is configured to accommodate a nuclear reactor and an annular gap space between the inner and outer steel cylindrical shells, a concrete donut structure at a bottom of the annular gap space, and a plurality of concrete columns spaced apart azimuthally around a circumference of the annular gap and extending in parallel from a top surface of the concrete donut structure to a top of the annular gap space. The outer and inner steel cylindrical shells and the concrete donut structure at least partially define one or more coolant channels extending through the annular gap space.