An in-core instrumentation system for a reactor module includes a plurality of in-core instruments connected to a containment vessel and a reactor pressure vessel at least partially located within the containment vessel. A reactor core is housed within a lower head that is removably attached to the reactor pressure vessel, and lower ends of the in-core instruments are located within the reactor core. The in-core instruments are configured such that the lower ends are concurrently removed from the reactor core as a result of removing the lower head from the reactor pressure vessel.

An in-core instrumentation system for a reactor module includes a plurality of in-core instruments connected to a containment vessel and a reactor pressure vessel at least partially located within the containment vessel. A reactor core is housed within a lower head that is removably attached to the reactor pressure vessel, and lower ends of the in-core instruments are located within the reactor core. The in-core instruments are configured such that the lower ends are concurrently removed from the reactor core as a result of removing the lower head from the reactor pressure vessel.

A thermal control system for a reactor pressure vessel comprises a plate having a substantially circular shape that is attached to a wall of the reactor pressure vessel. The plate divides the reactor pressure vessel into an upper reactor pressure vessel region and a lower reactor pressure vessel region. Additionally, the plate is configured to provide a thermal barrier between a pressurized volume located within the upper reactor pressure vessel region and primary coolant located within the lower reactor pressure vessel region. One or more plenums provide a passageway for a plurality of heat transfer tubes to pass through the wall of the reactor pressure vessel. The plurality of heat transfer tubes are connected to the plate.

A power module assembly may include a reactor vessel containing a primary coolant and one or more inlets configured to draw a secondary coolant from the containment cooling pool in response to a loss of power and/or a loss of coolant. One or more outlets may be submerged in the containment cooling pool and may be configured to vent the secondary coolant into the containment cooling pool. A heat exchanger may be configured to remove heat from the primary coolant, wherein the heat may be removed by circulating the secondary coolant from the containment cooling pool through the heat exchanger via natural circulation.

A power module assembly may include a reactor vessel containing a primary coolant and one or more inlets configured to draw a secondary coolant from the containment cooling pool in response to a loss of power and/or a loss of coolant. One or more outlets may be submerged in the containment cooling pool and may be configured to vent the secondary coolant into the containment cooling pool. A heat exchanger may be configured to remove heat from the primary coolant, wherein the heat may be removed by circulating the secondary coolant from the containment cooling pool through the heat exchanger via natural circulation.

A nuclear reactor is configured with an intermediate coolant loop for transferring thermal energy from the reactor core for a useful purpose. The intermediate coolant loop includes a bypass flowpath with an air heat exchanger for dumping reactor heat during startup and/or shutdown. A fluidic diode along the bypass flowpath asymmetrically restricts flow across the bypass flowpath, inhibiting flow in a first flow direction during a full power operating condition and allowing a relatively uninhibited flow in a second direction during a startup and/or shut down low power operating condition.

The present disclosure is directed to systems and methods useful for the construction and operation of a Modular Integrated Gas High-Temperature Reactor (MIGHTR). The MIGHTR includes a reactor core assembly disposed at least partially within a core baffle within a first high-pressure shell portion, a thermal transfer assembly disposed at least partially within a flow separation barrel within a second high-pressure shell portion. The longitudinal axes of the first high-pressure shell portion and the second high-pressure shell portion may be collinear. The reactor core assembly may be accessed horizontally for service, maintenance, and refueling. The core baffle may be flexibly displaceably coupled to the flow separation barrel. Coolant gas flows through the reactor core assembly and into the thermal transfer assembly where the temperature of the coolant gas is reduced. A plurality of coolant gas circulators circulate the cooled coolant gas from the thermal transfer assembly to the reactor core assembly.

The present disclosure is directed to systems and methods useful for the construction and operation of a Modular Integrated Gas High-Temperature Reactor (MIGHTR). The MIGHTR includes a reactor core assembly disposed at least partially within a core baffle within a first high-pressure shell portion, a thermal transfer assembly disposed at least partially within a flow separation barrel within a second high-pressure shell portion. The longitudinal axes of the first high-pressure shell portion and the second high-pressure shell portion may be collinear. The reactor core assembly may be accessed horizontally for service, maintenance, and refueling. The core baffle may be flexibly displaceably coupled to the flow separation barrel. Coolant gas flows through the reactor core assembly and into the thermal transfer assembly where the temperature of the coolant gas is reduced. A plurality of coolant gas circulators circulate the cooled coolant gas from the thermal transfer assembly to the reactor core assembly.

An object is to efficiently take heat out of a reactor core while retaining fission products. Included are fuel part provided with a covering part on a surface of a nuclear fuel and a heat conductive part.

An object is to efficiently take heat out of a reactor core while retaining fission products. Included are fuel part provided with a covering part on a surface of a nuclear fuel and a heat conductive part.