In a panel that uses the gamma radiation emitted by fission to produce electrical power, a source of an electrical current is connected to a layer of the panel made of a metal with a relatively high atomic number (Z) that forms an electron emitter. The emitter layer is surrounded by an insulation layer which in turn is surrounded by a relatively low Z value layer for collecting electrons from the emitter. Another layer of insulation and an outer sheath surround the collector. The improved panel may be used for reactor power level and power distribution measurements, and for initiating, maintaining or returning molten salt or metal coolants in the liquid state.

A method of refueling a nuclear reactor that includes the steps of removing the reactor vessel head and upper internals to a storage location and installing a cylindrical tank having open upper and lower ends, on the reactor vessel flange. The cylindrical tank is sealed to the reactor vessel and a penetration on the side of the cylindrical tank is sealed to a refueling canal that is connected to a spent fuel pool. The level of reactor coolant within the reactor vessel is then raised to at least partially fill the cylindrical tank to a level equal to that of the spent fuel pool. The refueling canal is then opened and a refueling machine supported on the reactor vessel is employed to transfer fuel assemblies between the core and the spent fuel pool.

Embodiments of the present disclosure include an integral nuclear reactor having a core fluidly coupled to an inlet chamber and to an outlet chamber. In some instances, the nuclear reactor may include a hub to house the core, the chambers, and the protective plug. The hub may include a window allowing a heat transfer fluid to flow from the outlet chamber, through the hub, and enter an annular space between the hub and a separation shell. The heat transfer fluid may flow into an inlet of a heat exchanger. The heat transfer fluid may flow through the heat exchanger before exiting at a heat exchanger outlet. The heat transfer fluid may enter an annular delay tank before flowing down an annular downcomer duct formed by the separation shell being housed in a reactor vessel. The heat transfer fluid may flow from the annular downcomer duct and into the inlet chamber.

This invention relates to nuclear power engineering and may be used in power plants with liquid metal lead containing coolants, particularly in fast neutron reactors.

The invention helps improve the safety of nuclear power plants. For this purpose, a nuclear power plant is proposed comprising: a reactor vessel with central and peripheral sections; a reactor cavity with a core located in the central part of the vessel; liquid metal coolant, at least one circulation pump for circulating the liquid metal coolant and at least one steam generator, located in the peripheral section of the vessel; a cavity with shielding gas located above the coolant; at least one shielding gas dispenser located in the peripheral section of the vessel, above the top cut of the steam generator in the suction area of the circulating pump comprising an intake and working sections, with the intake section located in the shielding gas cavity and having openings in its upper part, and the working section located under the free level of the liquid metal coolant.

A nuclear reactor system includes a nuclear reactor core disposed in a pressure vessel. Nuclear reactor system further includes control drums disposed longitudinally within the pressure vessel and laterally surrounding fuel elements and at least one moderator element of the nuclear reactor core to control reactivity. Each of the control drums includes a reflector material and an absorber material. Nuclear reactor system further includes an automatic shutdown controller and an electrical drive mechanism coupled to rotatably control the control drum. Automatic shutdown controller includes a counterweight to impart a bias and an actuator. To automatically shut down the nuclear reactor core during a loss or interruption of electrical power from a power source to the electrical drive mechanism, the actuator is coupled to the counterweight and responsive to the bias to align the absorber material of one or more control drums to face inwards towards the nuclear reactor core.

An enhanced architecture for a nuclear reactor core includes: (1) nuclear fuel tiles (S-Block); and (2) a thermal insulator and tube liners with a solid-phase moderator (U-Mod) to improve safety, reliability, heat transfer, efficiency, and compactness. In S-Block, nuclear fuel tiles include a fuel shape designed with an interlocking geometry pattern to optimize heat transfer between nuclear fuel tiles and into a fuel coolant and bring the fuel coolant in direct contact with the nuclear fuel tiles. Nuclear fuel tiles can be shaped with discontinuous nuclear fuel lateral facets and have fuel coolant passages formed therein to provide direct contact between the fuel coolant and the nuclear fuel tiles. In U-Mod, tube liners with hydrogen diffusivity retain hydrogen in the solid-phase moderator even at elevated temperatures and the thermal insulator insulates the solid-phase moderator from the nuclear fuel tiles.

A mobile reactor radiation shielding solution prevents activation of structural materials to reduce a radiation dosage risk to living organisms and accelerates timetables for transport. The shielding solution can include: in-vessel neutron shield, in-vessel shadow shield, transport shield, and module shadow shield. In-vessel neutron shield reduces and prevents the activation of the structural materials and significantly reduces the need for heavy shielding to shield against the gamma emissions from activated structural materials. In-vessel shadow shield provides neutron and gamma shielding between the reactor and a balance-of-plant (BOP) module and control system. In-vessel shadow shield is placed near the active nuclear core to minimize size of the shield while maximizing the protected arc to shield radiation workers while preparing the nuclear reactor for transport. Transport shield is used during transportation when living organisms come into proximity of the reactor. Module shadow shield shields reactor control components and BOP module during operation.

An enhanced architecture for a nuclear reactor core includes several technologies: (1) nuclear fuel tiles (S-Block); and (2) a high-temperature thermal insulator and tube liners with a low-temperature solid-phase moderator (U-Mod) to improve safety, reliability, heat transfer, efficiency, and compactness. In S-Block, nuclear fuel tiles include a fuel shape designed with an interlocking geometry pattern to optimize heat transfer between nuclear fuel tiles and into a fuel coolant and bring the fuel coolant in direct contact with the nuclear fuel tiles. Nuclear fuel tiles can be shaped with discontinuous nuclear fuel lateral facets and have fuel coolant passages formed therein to provide direct contact between the fuel coolant and the nuclear fuel tiles. In U-Mod, tube liners with low hydrogen diffusivity retain hydrogen in the low-temperature solid-phase moderator even at elevated temperatures and the high-temperature thermal insulator insulates the solid-phase moderator from the nuclear fuel tiles.