A nuclear reactor containment system with passive cooling capabilities. In one embodiment, the system includes an inner containment vessel for housing a nuclear steam supply system and an outer containment enclosure structure. An annular water-filled reservoir may be provided between the containment vessel and containment enclosure structure which provides a heat sink for dissipating thermal energy, in the event of a thermal energy release incident inside the containment vessel, the reactor containment system provides passive water and air cooling systems operable to regulate the heat of the containment vessel and the equipment inside. In one embodiment, cooling water makeup to the system is not required to maintain containment vessel and reactor temperatures within acceptable margins.

A nuclear reactor containment system with passive cooling capabilities. In one embodiment, the system includes an inner containment vessel for housing a nuclear steam supply system and an outer containment enclosure structure. An annular water-filled reservoir may be provided between the containment vessel and containment enclosure structure which provides a heat sink for dissipating thermal energy, in the event of a thermal energy release incident inside the containment vessel, the reactor containment system provides passive water and air cooling systems operable to regulate the heat of the containment vessel and the equipment inside. In one embodiment, cooling water makeup to the system is not required to maintain containment vessel and reactor temperatures within acceptable margins.

A method for protecting a nuclear reactor includes reconstructing a maximum linear power density released among the fuel rods of the nuclear fuel assemblies of the core; calculating the thermomechanical state and the burnup fraction of the rods; calculating a mechanical stress or deformation energy density in the cladding of one of the rods by using the said reconstructed maximum linear power density, the calculated thermomechanical states and the calculated burnup fractions, by means of a meta-model of a thermomechanical code; comparing the calculated mechanical stress or the calculated deformation energy density with a respective threshold; and stopping the nuclear reactor if the calculated mechanical stress or the calculated deformation energy density exceeds the respective threshold.

A method for protecting a nuclear reactor includes reconstructing a maximum linear power density released among the fuel rods of the nuclear fuel assemblies of the core; calculating the thermomechanical state and the burnup fraction of the rods; calculating a mechanical stress or deformation energy density in the cladding of one of the rods by using the said reconstructed maximum linear power density, the calculated thermomechanical states and the calculated burnup fractions, by means of a meta-model of a thermomechanical code; comparing the calculated mechanical stress or the calculated deformation energy density with a respective threshold; and stopping the nuclear reactor if the calculated mechanical stress or the calculated deformation energy density exceeds the respective threshold.

A curvilinear electromagnetic pump is configured to follow a curve, such as by coupling multiple linear pump segments together that are offset by an angle with respect to each other. The curvilinear electromagnetic pump can curve within two dimensions, or within three dimensions. The curvilinear electromagnetic pump allows for more efficient arrangement of components and systems within a nuclear reactor vessel and allows a significantly reduced reactor vessel height as compared to a linear pump arranged vertically. The curvilinear electromagnetic pump may follow the curvature of the reactor vessel wall and may be entirely disposed near the bottom of the reactor vessel.

A combined makeup tank and passive residual heat removal system that places a tube and shell heat exchanger within the core makeup tank. An intake to the tube side of the heat exchanger is connected to the hot leg of the reactor core and the outlet of the tube side is connected to the cold leg of the reactor core. The shell side of the heat exchanger is connected to a separate heat sink through a second heat exchanger.

A combined makeup tank and passive residual heat removal system that places a tube and shell heat exchanger within the core makeup tank. An intake to the tube side of the heat exchanger is connected to the hot leg of the reactor core and the outlet of the tube side is connected to the cold leg of the reactor core. The shell side of the heat exchanger is connected to a separate heat sink through a second heat exchanger.

A safety method for a reactor including a primary circuit in which a water-based primary fluid is intended to circulate, and a secondary circuit, in which a water-based secondary fluid is intended to circulate, the secondary circuit being hydraulically isolated from the primary circuit and including a steam generator is provided. In the event of a meltdown of the core of the reactor with the formation of a corium bath in a bottom of the vessel: in response to the detection of the formation of a liquid metallic layer at the surface of the corium bath: the method provides for setting the secondary circuit in fluidic communication with the primary circuit so that the secondary fluid follows the primary circuit to flow inside the vessel over the liquid metallic layer of the corium bath.

A safety method for a reactor including a primary circuit and a secondary circuit fluidly isolated from the primary circuit, and a steam generator, and in the event of a meltdown of the core of the reactor with the formation of a corium bath in a bottom of the vessel and the formation of a liquid metallic layer at the surface of the corium bath, the method includes: a break-up by explosion of the fluidic insulation to set the secondary circuit in fluidic communication with the primary circuit so that the secondary fluid follows the primary circuit to flow inside the vessel over the liquid metallic layer of the corium bath.

The invention relates to a heating rod for a pressurizer of a primary cooling system of a pressurized-water nuclear reactor, the rod comprising a metal outer shell (36) of longitudinally elongate shape having an external surface (62), and a heating element (40) mounted inside the shell (36). It comprises an anti-corrosion coating (60) covering at least part of the external surface (62) of the shell (36).