Abstract: Example embodiments disclose a passive system of power and cooling with a liquid metal for a digital system. The passive system may include a digital device operatively coupled to a printed circuit board, a hollow conductive channel body attached to the printed circuit board to circulate the liquid metal to flow within the conductive channel so as to convey electrical power to the digital device during a power loss and transfer heat generated by the digital device, and a tube to deliver the liquid metal in and out of the hollow conductive channel body. A method of operating a liquid metal may involve the use of the passive system.

Abstract: An entrainment-reducing assembly may include a container configured to hold a liquid. A venting arrangement may extend into an upper portion of the container and be configured to direct condensable and non-condensable gases into the container. A suction structure may extend into a lower portion of the container and be configured to carry out an extraction of excess liquid from the container caused by condensed gases. A deflector may be disposed between the suction structure and the venting arrangement within the container. As a result, an entrainment of uncondensed gases during the extraction of the liquid by the suction structure may be reduced or prevented, thereby protecting the pump from cavitation and failure.

Abstract: A nuclear reactor includes a coolant fluid thermal monitoring array configured to monitor coolant fluid circulation in a downcomer flow channel of a nuclear reactor. The thermal monitoring array includes one or more flowmeter assemblies configured to monitor coolant fluid flow through separate flow channel portions. Each flowmeter assembly includes a first sensor coupled to a heating element and at least one second sensor at least partially insulated from the heating element. The first and second sensors may measure temperatures of separate flowstreams of coolant fluid through a downcomer flow channel portion. Temperature data generated by the first and second sensors of the flowmeter assemblies may be processed to monitor coolant fluid flow through the downcomer flow channel portions. The temperature data may be processed to monitor coolant fluid temperature. The temperature data may be processed to monitor a location of a fluid two-phase interface in the downcomer flow channel.

Abstract: A method for suppressing a pyrophoric metal fire may include arranging a suppression system above a containment structure. The suppression system includes a first extinguishing agent. The containment structure is configured to contain and isolate a pyrophoric metal from ambient air. The suppression system is configured to activate upon a leak and ignition of the pyrophoric metal so as to release the first extinguishing agent to suppress the pyrophoric metal fire.

Abstract: An entrainment-reducing assembly may include a container configured to hold a liquid. A venting arrangement may extend into an upper portion of the container and be configured to direct condensable and non-condensable gases into the container. A suction structure may extend into a lower portion of the container and be configured to carry out an extraction of excess liquid from the container caused by condensed gases. A deflector may be disposed between the suction structure and the venting arrangement within the container. As a result, an entrainment of uncondensed gases during the extraction of the liquid by the suction structure may be reduced or prevented, thereby protecting the pump from cavitation and failure.

Abstract: A liquid metal-cooled nuclear reactor includes, within a reactor pressure vessel, a primary electromagnetic pump (EMP) circulating liquid metal coolant through the reactor core and a backflow EMP. The nuclear reactor may be configured to at least partially mitigate liquid metal coolant backflow in response to a primary EMP failure. The backflow EMP is coupled in series with the primary EMP within the reactor pressure vessel. The backflow EMP may be selectively activated in response to failure of the primary EMP to mitigate liquid metal backflow through the primary EMP. The primary EMP and backflow EMP may receive power from separate power sources. Multiple backflow EMPs may be coupled in parallel to the primary EMP via parallel liquid metal coolant lines. A nuclear reactor may include multiple primary EMPs and multiple sets of backflow EMPs, where each separate set of backflow EMPs is coupled to a separate primary EMP.

Abstract: A sodium-cooled nuclear reactor includes at least one electromagnetic pump assembly and a backflow reduction pipe. The backflow reduction pipe may include an inlet, an outlet, at least one tubular section having a first length and a first diameter, and at least one fluid diode section between the inlet and the outlet.

Abstract: A passive fire response system is configured to suppress a metallic fire. The system includes a reservoir containing an ionic liquid, at least one outlet in communication with the reservoir, a valve arranged between the reservoir and the outlet, a sensor configured to sense at least one of a hydrogen concentration and a temperature and/or heat, and a controller configured to open the valve and release the ionic liquid if an output from the sensor indicates that the at least one of the hydrogen concentration and the temperature equals or exceeds at least one of a threshold hydrogen concentration and a threshold temperature.

Abstract: A passive safety system for removing decay heat from a nuclear power system may comprise a shroud structure and a heat generator that is within the shroud structure. A thermoelectric device may be disposed in thermal contact with the heat generator. The thermoelectric device is configured to generate a voltage based on a temperature difference between opposite parts of the thermoelectric device. A fan arrangement is disposed above the heat generator and in electrical connection with the thermoelectric device. The fan arrangement is configured to increase a coolant flow through the coolant passage to the outlet opening based on the voltage from the thermoelectric device.

Abstract: A method for suppressing a pyrophoric metal fire may include arranging a suppression system above a containment structure. The suppression system includes a first extinguishing agent. The containment structure is configured to contain and isolate a pyrophoric metal from ambient air. The suppression system is configured to activate upon a leak and ignition of the pyrophoric metal so as to release the first extinguishing agent to suppress the pyrophoric metal fire.

Abstract: A method of removing a radioactive material from a gas includes directing the gas through a bed of salt, wherein the gas includes water vapor and the radioactive material. The salt constitutes more than 50 percent by weight of the bed. The method additionally includes condensing the water vapor in the bed and dissolving a portion of the salt to form a salt solution. The method further includes absorbing the radioactive material into the salt solution while a remainder of the gas passes through the bed. A salt filtration system configured to perform the method may be implemented as a pre-filter (or post-filter) to an existing filter unit or as a standalone filter.

Abstract: Example embodiments disclose a passive system of power and cooling with a liquid metal for a digital system. The passive system may include a digital device operatively coupled to a printed circuit board, a hollow conductive channel body attached to the printed circuit board to circulate the liquid metal to flow within the conductive channel so as to convey electrical power to the digital device during a power loss and transfer heat generated by the digital device, and a tube to deliver the liquid metal in and out of the hollow conductive channel body. A method of operating a liquid metal may involve the use of the passive system.

Abstract: A method of removing a radioactive material from a gas includes directing the gas through a bed of salt, wherein the gas includes water vapor and the radioactive material. The salt constitutes more than 50 percent by weight of the bed. The method additionally includes condensing the water vapor in the bed and dissolving a portion of the salt to form a salt solution. The method further includes absorbing the radioactive material into the salt solution while a remainder of the gas passes through the bed. A salt filtration system configured to perform the method may be implemented as a pre-filter (or post-filter) to an existing filter unit or as a standalone filter.

Abstract: A method of stabilizing a fuel containing a reactive sodium metal may include puncturing a cladding of a fuel pin enclosing the fuel containing the reactive sodium metal to form an injection passage and an extraction passage. A reaction gas may be injected into the fuel pin through the injection passage to react with the reactive sodium metal to form a stable sodium compound. A ratio of a product gas and a remaining quantity of the reaction gas exiting the fuel pin through the extraction passage is subsequently measured, wherein the product gas is a reaction product of the reaction gas and the reactive sodium metal within the fuel pin. Once the measured ratio indicates that a reaction between the reaction gas and the reactive sodium metal is complete, the injection passage and the extraction passage are sealed so as to confine the stable sodium compound within the fuel pin.

Abstract: A chimney of a nuclear reactor may include a hollow body with an interior surface and an opposing exterior surface; and a plurality of trip structures on the exterior surface of the hollow body. The chimney may be used in a method of improving a core inlet enthalpy of a nuclear reactor. The method may include interrupting a downward flow of water within a downcomer region of a reactor pressure vessel with a plurality of first trip structures. The downcomer region is an annular space defined by the reactor pressure vessel and a chimney within the reactor pressure vessel. The plurality of first trip structures are disposed on an exterior surface of the chimney.

Abstract: A passive shutdown system for a liquid metal cooled reactor may include a tube and a neutron absorber within the tube. The tube may be configured to extend through a core of the liquid metal cooled reactor. The tube has an upper end and a lower end. The tube defines a flow path for a liquid metal coolant. The neutron absorber is a mobile structure configured to partially obstruct a flow of the liquid metal coolant within the flow path. A method of operating a liquid metal cooled reactor may involve the use of the passive shutdown system.

Abstract: A method of stabilizing a fuel containing a reactive sodium metal may include puncturing a cladding of a fuel pin enclosing the fuel containing the reactive sodium metal to form an injection passage and an extraction passage. A reaction gas may be injected into the fuel pin through the injection passage to react with the reactive sodium metal to form a stable sodium compound. A ratio of a product gas and a remaining quantity of the reaction gas exiting the fuel pin through the extraction passage is subsequently measured, wherein the product gas is a reaction product of the reaction gas and the reactive sodium metal within the fuel pin. Once the measured ratio indicates that a reaction between the reaction gas and the reactive sodium metal is complete, the injection passage and the extraction passage are sealed so as to confine the stable sodium compound within the fuel pin.

Abstract: A cooling system for spent nuclear fuel may include a device configured to generate electricity using energy emitted from the spent nuclear fuel. The cooling system may be configured to use the electricity when cooling the spent nuclear fuel. A cask for storage, transport, or storage and transport of spent nuclear fuel may include the cooling system and a container configured to hold the spent nuclear fuel. A method for cooling spent nuclear fuel may include generating electricity using energy emitted from the spent nuclear fuel, and using the electricity in a cooling system for the spent nuclear fuel when cooling the spent nuclear fuel.

Abstract: An entrainment-reducing assembly may include a container configured to hold a liquid. A venting arrangement may extend into an upper portion of the container and be configured to direct condensable and non-condensable gases into the container. A suction structure may extend into a lower portion of the container and be configured to carry out an extraction of excess liquid from the container caused by condensed gases. A deflector may be disposed between the suction structure and the venting arrangement within the container. As a result, an entrainment of uncondensed gases during the extraction of the liquid by the suction structure may be reduced or prevented, thereby protecting the pump from cavitation and failure.