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: 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 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: 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: 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: A method of cleaning a submerged surface covered by a liquid medium includes injecting a cleaning liquid with a submerged fluid jet through the liquid medium at the submerged surface. The method may also include introducing at least one of a non-reactive gas and a reactive gas with the cleaning liquid through the submerged fluid jet.

Abstract: A chimney structure according to a non-limiting 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: 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: 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 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 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 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 method of cleaning a submerged surface covered by a liquid medium includes injecting a cleaning liquid with a submerged fluid jet through the liquid medium at the submerged surface. The method may also include introducing at least one of a non-reactive gas and a reactive gas with the cleaning liquid through the submerged fluid jet.

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 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.