A high-temperature containment-isolation system for transferring heat from a nuclear reactor containment to a high-pressure heat exchanger is presented. The system uses a high-temperature, low-volatility liquid coolant such as a molten salt or a liquid metal, where the coolant flow path provides liquid free surfaces a short distance from the containment penetrations for the reactor hot-leg and the cold-leg, where these liquid free surfaces have a cover gas maintained at a nearly constant pressure and thus prevent high-pressures from being transmitted into the reactor containment, and where the reactor vessel is suspended within a reactor cavity with a plurality of refractory insulator blocks disposed between an actively cooled inner cavity liner and the reactor vessel.

A nuclear reactor includes a reactor core comprising fissile material disposed in a reactor pressure vessel. A radiological containment contains the nuclear reactor. A containment compartment contains the radiological containment. A heat sink includes a chimney configured to develop an upward-flowing draft in response to heated fluid flowing into a lower portion of the chimney. A fluid conduit is arranged to receive fluid from the containment compartment and to discharge into the chimney. A filter may be provided, with the fluid conduit including a first fluid conduit arranged to receive fluid from the containment compartment and to discharge into an inlet of the filter, and a second fluid conduit arranged to receive fluid from an outlet of the filter and to discharge into the chimney. As the draft is developed passively, there is no need for a blower or pump configured to move fluid through the fluid conduit.

A nuclear reactor includes a reactor core comprising fissile material disposed in a reactor pressure vessel. A radiological containment contains the nuclear reactor. A containment compartment contains the radiological containment. A heat sink includes a chimney configured to develop an upward-flowing draft in response to heated fluid flowing into a lower portion of the chimney. A fluid conduit is arranged to receive fluid from the containment compartment and to discharge into the chimney. A filter may be provided, with the fluid conduit including a first fluid conduit arranged to receive fluid from the containment compartment and to discharge into an inlet of the filter, and a second fluid conduit arranged to receive fluid from an outlet of the filter and to discharge into the chimney. As the draft is developed passively, there is no need for a blower or pump configured to move fluid through the fluid conduit.

The invention relates to safety systems for nuclear power plants (NPP), and can be used in the event of reactor vessel and NPP containment failure. The melt cooling and confinement system includes a cone-shaped guide plate installed under the reactor vessel bottom, cantilever girder installed under the guide plate and supporting the same, core catcher installed under the cantilever girder and equipped with cooled cladding in form of a multi-layer vessel for protection of the external heat-exchange wall from dynamic, thermal and chemical impacts, and filler material for melt dilution inside the multi-layer vessel. The said multi-layer vessel contains external and internal metal walls with filler of poorly heat-conductive in relation to the wall material in between. Filler thickness h.sub.fil shall meet the following requirement: 0.8 h.sub.ext<h.sub.fil<1.6 h.sub.ext, where h.sub.ext is vessel external wall thickness.

The invention relates to safety systems for nuclear power plants (NPP), and can be used in the event of reactor vessel and NPP containment failure. The melt cooling and confinement system includes a cone-shaped guide plate installed under the reactor vessel bottom, cantilever girder installed under the guide plate and supporting the same, core catcher installed under the cantilever girder and equipped with cooled cladding in form of a multi-layer vessel for protection of the external heat-exchange wall from dynamic, thermal and chemical impacts, and filler material for melt dilution inside the multi-layer vessel. The said multi-layer vessel contains external and internal metal walls with filler of poorly heat-conductive in relation to the wall material in between. Filler thickness h.sub.fil shall meet the following requirement: 0.8 h.sub.ext<h.sub.fil<1.6 h.sub.ext, where h.sub.ext is vessel external wall thickness.

The invention relates to safety systems for nuclear power plants (NPP), and can be used in the event of reactor vessel and NPP containment failure. The melt cooling and confinement system includes a cone-shaped guide plate installed under the reactor vessel bottom, cantilever girder installed under the guide plate and supporting the same, core catcher installed under the cantilever girder and equipped with cooled cladding in form of a multi-layer vessel for protection of the external heat-exchange wall from dynamic, thermal and chemical impacts, and filler material for melt dilution inside the multi-layer vessel. The said multi-layer vessel contains internal and external metal layers with an intermediate layer in the form of a non-metal filler located in between. Bearing ribs are installed between the internal and external layers at an azimuth pitch (Spitch) that meets the following criterion: dext/15<spitch<dext/5, where dext is external diameter of the vessel.

The invention relates to safety systems for nuclear power plants (NPP), and can be used in the event of reactor vessel and NPP containment failure. The melt cooling and confinement system includes a cone-shaped guide plate installed under the reactor vessel bottom, cantilever girder installed under the guide plate and supporting the same, core catcher installed under the cantilever girder and equipped with cooled cladding in form of a multi-layer vessel for protection of the external heat-exchange wall from dynamic, thermal and chemical impacts, and filler material for melt dilution inside the multi-layer vessel. The said multi-layer vessel contains internal and external metal layers with an intermediate layer in the form of a non-metal filler located in between. Bearing ribs are installed between the internal and external layers at an azimuth pitch (Spitch) that meets the following criterion: dext/15<spitch<dext/5, where dext is external diameter of the vessel.

The invention relates to safety systems for nuclear power plants (NPP), and can be used during severe accidents leading to reactor vessel and NPP containment failure. The melt cooling and confinement system includes a cone-shaped guide plate installed under the reactor vessel bottom, cantilever girder installed under the guide plate and supporting the same, core catcher installed under the cantilever girder and equipped with cooled cladding in form of a multi-layer vessel for protection of the external heat-exchange wall from dynamic, thermal and chemical impacts, and filler material for melt dilution inside the multi-layer vessel. The said multi-layer vessel has external and internal metal walls with a filler that is highly heat-conductive in relation to wall material in between, where filler material thickness h.sub.fil meets the following criterion: 1.2h.sub.ext<h.sub.fil<2.4h.sub.ext, where h.sub.ext is vessel external wall thickness.

The invention relates to safety systems for nuclear power plants (NPP), and can be used during severe accidents leading to reactor vessel and NPP containment failure. The melt cooling and confinement system includes a cone-shaped guide plate installed under the reactor vessel bottom, cantilever girder installed under the guide plate and supporting the same, core catcher installed under the cantilever girder and equipped with cooled cladding in form of a multi-layer vessel for protection of the external heat-exchange wall from dynamic, thermal and chemical impacts, and filler material for melt dilution inside the multi-layer vessel. The said multi-layer vessel has external and internal metal walls with a filler that is highly heat-conductive in relation to wall material in between, where filler material thickness h.sub.fil meets the following criterion: 1.2h.sub.ext<h.sub.fil<2.4h.sub.ext, where h.sub.ext is vessel external wall thickness.

A sparger includes a main pipe connecting inside and outside of a water tank having a storage space therein for storing cooling water, so as to define a flow path through which steam and air containing radioactive materials generated outside the water tank are discharged into the cooling water, a header part connected to one end portion of the main pipe located in the storage space, and having a storage chamber in which the steam and air transferred through the main pipe are collected, and a plurality of discharge nozzles disposed in a spacing manner, each having inlet and outlet formed on one end located in the storage chamber and another end located in the storage space, respectively, to discharge the steam and air from the storage chamber to the storage space, and at least some of the plurality of discharge nozzles protruding from the header part by different lengths.