Abstract: In one embodiment, the fuel bundle for a liquid metal cooled reactor includes a channel, a nose assembly secured to a lower end of the channel, and a plurality of fuel rods disposed within the channel. At least one of the fuel rods has at least one guard ring surround the fuel rod and spacing the fuel rod from adjacent fuel rods.

Abstract: A chimney structure according to a non-liming example embodiment may include a guide structure defining an opening, and a plurality of chimney partitions including 1 to N chimney partitions concentrically arranged and spaced apart from each other on the guide structure. The 1 to N chimney partitions may each define a curved opening over the opening the guide structure. N may be an integer greater than 1.

Abstract: Safety valves accurately control closure and opening of fluid passage through the valve. Valves include a barrier that blocks the fluid until removal only by a high-energy projectile. Following removal and opening, the barrier or the projectile can flow through the valve, which remains open. Bullets, pneumatic pistons, shot, coilgun pellets and any other forceful projectile may impact and remove the barrier. The projectile is actuated with any type of chemical reaction, firing pin, spring release, accelerating circuit, ignition circuit. Catchers in the valve envelop or otherwise retain the projectile or barrier pieces and enter the fluid flow of the opened valve without blocking it. Disruptable barriers include strong but breakable glass plates, thin steel sheets, a rotatable door and other barriers that can withstand potentially over 10,000 psi of fluid pressure while closing the valve. Valves can use circuits to both monitor valve open/closed status and initiate firing the projectile.

Abstract: In one embodiment, the fuel bundle for a liquid metal cooled reactor includes a channel, a nose assembly secured to a lower end of the channel, and a plurality of fuel rods disposed within the channel. At least one of the fuel rods has at least one guard ring surround the fuel rod and spacing the fuel rod from adjacent fuel rods.

Abstract: In one embodiment, a fuel bundle for a liquid metal cooled reactor includes a channel, a nose assembly secured to a lower end of the channel, a plurality of fuel rods disposed within the channel, and an internal mixer disposed within the channel above the plurality of fuel rods. The internal mixer includes peripheral flow control members and interior flow control members. The peripheral flow control members are located near walls of the channel, and the interior flow control members are located towards a longitudinal center of the housing. At least one of the peripheral flow control members is configured to direct liquid metal flowing through the channel towards an interior of the channel, and at least one of the interior flow control members is configured to direct liquid metal flowing through the channel away from the interior of the channel.

Abstract: A system and a method for capturing gaseous, particulate and liquid radioactive material released from primary containment of a Light Water Reactor (LWR) during severe accident conditions. The system includes a below-grade media area, connected to a reactor pressure vessel (RPV) and portions of primary containment, providing varying levels of adsorption/absorption of the radioactive material. The media area is located on-site to offer a passive, self-regulating structure for stabilizing a nuclear reactor. The capture system provides for liquid drainage and gaseous venting of the radioactive material, and a treatment capable of treating the media following stabilization of the reactor.

Abstract: A method of fabricating a liquid-metal coolant includes adding nanoparticles to the liquid-metal coolant to change neutronic properties of the liquid-metal coolant. The nanoparticles have neutronic properties different from that of the liquid-metal coolant.

Abstract: A method for processing a coolant includes filtering a coolant using a first filtration system to generate a first filtered material, and filtering the filtered coolant using a second filtration system to generate a second filtered material. The second filtration system is different from the first filtration system. The first filtered material is transferred to a first waste treatment container and converted to a first waste product for permanent disposal, and the second waste product is transferred to a second waste treatment container and converted to a second waste product for permanent disposal.

Abstract: A method of fabricating metallic fuel from surplus plutonium may include combining plutonium oxide powder and uranium oxide powder to obtain a mixed powder with reduced proliferation potential. The mixed powder may be electroreduced in a bath of molten salt so as to convert the mixed powder to a first alloy. The first alloy may be pressed to remove a majority of the molten salt adhered to the first alloy to form a pressed alloy-salt mixture. The first alloy may be isolated from the salt by melting the pressed alloy-salt mixture. The first alloy may be further processed to fabricate a fuel rod. Accordingly, the metallic fuel produced may be used in a fast reactor system, such as a Power Reactor Innovative Small Module (PRISM).

Abstract: A system for monitoring a state of a reactor core in a nuclear reactor may include an internal monitoring device located inside the reactor core, the internal monitoring device including one or more internal sensor arrays configured to take measurements of conditions of the reactor core at different vertical regions within the reactor core to generate internal measurement data; an external monitoring device located in the reactor structure outside the reactor core, the external monitoring device including one or more external sensor arrays configured to take measurements of conditions of the reactor core at positions outside the reactor core corresponding the plurality of different vertical regions within the reactor core to generate external measurement data, and a transmitter configured to wirelessly transmit the external measurement data; and a receiver station configured to determine a state of the reactor core based on the external and internal measurement data.

Abstract: A temperature change detection apparatus for monitoring temperature change in various portions of a large space includes a trip logic unit configured to execute a trip operation based on receipt of a trip signal at the trip logic unit; a plurality of temperature sensors each including a sensing portion composed of optical fiber cable and each being configured to generate light information indicating an amount of Brillouin scattering that occurs within the sensing portion; a plurality of monitoring units configured such that each monitoring unit determines a temperature value corresponding to each temperature sensor connected to the monitoring unit based on an amount of Brillouin scattering indicated by the light information generated by each of the connected temperature sensors, an each monitoring unit generates a trip signal when a determined temperature value exceeds a running average by more than a threshold amount.

Abstract: Mobile apparatuses move within contaminated fluid to create fluid flows against structures that remove and prevent contaminant deposition on structure surfaces immersed in the fluid. Unsettling flows in water may exceed approximately 2 m/s for radionuclide particles and solutes found in nuclear power plants. Mobile apparatuses include pressurized liquid from a pump or pressurized source that can be chemically and thermally treated to maximize deposition removal. When spraying the pressurized liquid to create the deposition-removing flow, mobile apparatuses may be self-propelled within the fluid about an entire surface to be cleaned. Mobile apparatuses include filters keyed to remove the contaminants moved into the coolant by the flow, and by taking in ambient fluid, enable such filtering of the ambient fluid along with a larger flow volume and propulsion. Propulsion and the pressurized liquid in turn enhance intake of ambient fluid.

Abstract: A thermal-pumping apparatus according to a non-limiting example embodiment may include a first volume structure defining a first inlet opening and a first outlet opening in fluid communication with a first volume, a second volume structure defining a second inlet opening and a second outlet opening in fluid communication with a second volume, and a connection structure joining the first outlet opening of the first volume structure to the second inlet opening of the second volume structure. The connection structure may include a one-directional valve configured to allow fluid flow between the first and second volume structures in one direction only from the first volume of the first volume structure to the second volume of the second volume structure.

Abstract: A method for stabilizing a nuclear material may include electrolytically reducing the nuclear material in a first molten salt electrolyte of an electroreducer to produce a reduced material. A reducer waste may accumulate in the first molten salt electrolyte as a byproduct of the electroreduction. After the electroreduction, the reduced material may be electrolytically dissolved in a second molten salt electrolyte of an electrorefiner to produce a purified metal product on a refiner cathode assembly of the electrorefiner. As a result of the electrorefining, a first refiner waste may accumulate in the second molten salt electrolyte and a second refiner waste may accumulate in a refiner anode assembly of the electrorefiner. The reducer waste from the electroreducer and the first refiner waste from the electrorefiner may be converted into a ceramic waste form, while the second refiner waste from the electrorefiner may be converted into a metallic waste form.

Abstract: A seismic slip joint may include a fixed sealing surface, a moveable sealing surface, and a solenoid device. The moveable sealing surface is configured to engage the fixed sealing surface to form a sealing interface during a deactivated state. The sealing interface may be a juncture that precludes passage of a fluid therethrough. The solenoid device is configured to switch between the deactivated state and an activated state. The solenoid device may include a piston and a spring structure. The piston is connected to the moveable sealing surface. The spring structure exerts a force on the piston so as to press the moveable sealing surface against the fixed sealing surface to form the sealing interface during the deactivated state. The piston may be configured to compress the spring structure and retract during the activated state so as to separate the moveable sealing surface from the fixed sealing surface.

Abstract: A system configured to passively filter radioactive materials from a flow may include one or more particulate removal devices; one or more water removal devices; and/or one or more radionuclide removal devices. At least one of the one or more particulate removal devices may mechanically remove particulates of the radioactive materials from the flow. At least one of the one or more water removal devices mechanically may remove water from the flow. At least one of the one or more radionuclide removal devices may remove radioactive aerosols, reactive radioactive gases, or radioactive aerosols and reactive radioactive gases from the flow using engineered filter media. A filter may include a body, including an inlet and an outlet. The body may be configured to store filter media, to contain pressure from gas explosions, and/or to allow the stored filter media to move toward the outlet when pressure at the inlet increases.

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: Example embodiments include a vapor forming apparatus, system and/or method for producing vapor from radioactive decay material. The vapor forming apparatus including an insulated container configured to enclose a nuclear waste container. The nuclear waste container includes radioactive decay material. The insulated container includes an inlet valve configured to receive vapor forming liquid. The radioactive decay material transfers heat to the vapor forming liquid. The insulated container also includes an outlet valve configured to output the vapor forming liquid heated by the radioactive decay material.

Abstract: A system and a method for capturing gaseous, particulate and liquid radioactive material released from primary containment of a Light Water Reactor (LWR) during severe accident conditions. The system includes a below-grade media area, connected to a reactor pressure vessel (RPV) and portions of primary containment, providing varying levels of adsorption/absorption of the radioactive material. The media area is located on-site to offer a passive, self-regulating structure for stabilizing a nuclear reactor. The capture system provides for liquid drainage and gaseous venting of the radioactive material, and a treatment capable of treating the media following stabilization of the reactor.

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.