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: Methods implemented by at least one electronic processor for generating pointwise fast neutron spectra may include receiving composition data; receiving source data or calculating the source data; receiving nuclear data; and calculating the pointwise fast neutron spectrum based on numerical integration using the composition, source, and nuclear data. Systems for generating pointwise fast neutron spectra may include a bus; at least one electronic processor connected to the bus; an input device connected to the bus; and a communication link connected to the bus. The at least one electronic processor may be configured to receive composition data from the input device via the bus, to receive source data from the input device via the bus or to calculate the source data, to receive nuclear data from the communication link via the bus, and to calculate the pointwise fast neutron spectrum based on numerical integration using the composition, source, and nuclear data.

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: 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, 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 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 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 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 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: 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: 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 device for monitoring a reactor during normal and off-normal operating conditions may include a case formed of a rigid material, the case including a shielding layer configured to insulate an internal portion of the device from external heat and radiation; a coupling unit configured to adhere the case to a surface location of a reactor; a sensing unit configured to generate environmental measurements by measuring environmental conditions in the vicinity of the reactor; a data processing unit configured to generate measurement data by processing the environmental measurements; a transmitter configured to transmit the measurement data externally from the device; and a power unit configured to power the device independently of an external power source.

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: Methods implemented by at least one electronic processor for generating pointwise fast neutron spectra may include receiving composition data; receiving source data or calculating the source data; receiving nuclear data; and calculating the pointwise fast neutron spectrum based on numerical integration using the composition, source, and nuclear data. Systems for generating pointwise fast neutron spectra may include a bus; at least one electronic processor connected to the bus; an input device connected to the bus; and a communication link connected to the bus. The at least one electronic processor may be configured to receive composition data from the input device via the bus, to receive source data from the input device via the bus or to calculate the source data, to receive nuclear data from the communication link via the bus, and to calculate the pointwise fast neutron spectrum based on numerical integration using the composition, source, and nuclear data.