Abstract: A method for applying a coating to a defect area of a reactor component includes forming a patch on the reactor component at the defect area using a plasma-spray coating process. The plasma-spray coating process includes grounding the reactor component and a power supply of a plasma gun to a common ground such that a potential difference exists between the reactor component and a cathode of the plasma gun, and concurrently directing an ion-etching stream and a coating stream towards the region of the reactor component using the plasma gun while maintaining a desired distance between the plasma gun and the region of the reactor component. The directing the ion-etching stream includes heating the region of the reactor component using a plasma stream exiting a spray nozzle of the plasma gun. The coating stream includes droplets of a coating material.

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 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 and apparatus for a boiling water reactor (BWR) jet pump inlet mixer compliant stop. The inlet mixer compliant stop may be installed in a pocket area between a riser pipe and an inlet mixer of a BWR jet pump assembly. The inlet mixer compliant stop includes a main body and a foot that are separated via the tightening of one or more jacking bolts used to connect the main body and the foot. A cold spring attached to the main body provides a lateral force that is imparted on the inlet mixer, to force the inlet mixer away from a centerline of the riser pipe. A precise lateral force may be imparted on the inlet mixer by gauging a width of a gap between opposing bosses on a front face of the main body and a distal end of the cold spring. The inlet mixer compliant stop imparts a greater lateral force on the inlet mixer as the jacking bolts are tightened, further separating the main body from the foot, as the gap between the opposing bosses is reduced.

Abstract: An apparatus configured to structurally replace a cracked weld in a nuclear plant may include: a first body portion that includes a first gripping portion; a second body portion that includes a second gripping portion; a wedge portion between the first and second body portions; and/or an adjustment portion. The first body portion may be configured to slidably engage the second body portion. The wedge portion may be configured to exert force on the slidably engaged first and second body portions. The adjustment portion may be configured to increase or decrease the force exerted by the wedge portion on the slidably engaged first and second body portions. When the adjustment portion increases the force exerted by the wedge portion on the slidably engaged first and second body portions, a distance between the first and second gripping portions may decrease.

Abstract: A nuclear reactor is operated with irradiation target holders fit in open locations inside of an operating commercial nuclear core and placed with ends at vertical bottom and top of the core or any position therebetween to directly expose holders to nuclear fuel reactions. Holders have ends and overall shape that are joined with existing reactor structures, while fitting closely with fuel and moderator and being easily removable from the same. Holders are fabricated of any reactor-compatible material that will retain irradiation targets and daughter products. Holders securely retain irradiation targets and daughter products of any shape or phase throughout reactor operation. Holders can be installed during reactor outages and irradiated during operation without risk of movement or interference with operation. After a desired period of operation and irradiation, holders can be harvested from the core independent of other core structures and fuel.

Abstract: A pyrotechnic-actuated valve assembly may include an insert body having an inlet, an outlet, and a flow path extending from the inlet to the outlet. The insert body is formed of a first alloy. A shear structure is bonded to the outlet of the insert body so as to close the flow path. The shear structure is formed of a second alloy. The second alloy of the shear structure is bonded to the first alloy of the insert body so as to form a hermetic seal. The dual-alloy nature of the valve assembly allows a relatively clean shearing of the shear structure during actuation, thus reducing or preventing the occurrence of deformation and/or material fragments in the flow path.

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 computing device within a reflective memory system includes a memory block and a special purpose processor. The memory block includes a plurality of memory areas, which are configured to store data of a corresponding one of a plurality of external devices. The special purpose processor is configured to intercept a write request. The write request is associated with a first external device of the plurality of external devices, and the first external device is associated with a first memory area of the plurality of memory areas. The special purpose processor is configured to determine whether the write request is valid or invalid, write the data of the first external device to the first memory area if the write request is valid, and prevent the data of the first external device from being written to the memory block if the write request is invalid.

Abstract: A system and a method for a passive containment vent system for a Boiling Water Reactor (BWR). The system is capable of venting and scrubbing a gaseous discharge from the primary containment of the BWR over a prolonged period of time leading up to or following a serious plant accident, without the need for monitoring by on-site plant personnel. External electrical power is not required (following initial activation of the system) in order to operate the containment vent system. The system may protect the integrity of primary containment during and following the serious plant accident.

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: Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may be supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.

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: 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: An insulated solution injector may include an outer tube and an inner tube arranged within the outer tube. The outer tube and the inner tube may define an annular space therebetween, and the inner tube may define a solution space within. The annular space may be configured so as to insulate the solution within the solution space. As a result, the solution may be kept to a temperature below its decomposition temperature prior to injection. Accordingly, the decomposition of the solution and the resulting deposition of its constituents within the solution space may be reduced or prevented, thereby decreasing or precluding the occurrence of a blockage.

Abstract: A remotely operated vehicle (ROV) for inspecting a core shroud having an outer surface may include: a body configured to be operatively connected to a tether; and/or a sensor, configured to be operatively connected to the body, and configured to provide inspection information of the shroud. The tether may be configured to provide vertical position information for the ROV relative to the outer surface. A system for inspecting a core shroud may include: a trolley; an arm; the tether; and/or the ROV. The arm may be configured to be operatively connected to the trolley. The ROV may be configured to be operatively connected to the arm via the tether. A method for inspecting a core shroud may include: installing a system for inspecting the shroud on the shroud; driving the system horizontally around the shroud; and/or using a sensor of the system to inspect the shroud.

Abstract: One embodiment provides a multi-segment rod that includes a plurality of rod segments. The rod segments are removably mated to each other via mating structures in an axial direction. An irradiation target is disposed within at least one of the rod segments, and at least a portion of at least one mating structure includes one and/or more combinations of neutron absorbing materials.

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 shutting down a nuclear reactor may include compressing a scram gas that is in fluid communication with a scram accumulator. The scram accumulator defines a chamber therein and contains bellows within the chamber. The bellows are configured to hold a scram liquid in isolation of the scram gas. The scram gas exerts a compressive force on the bellows in a form of stored energy. The method may additionally include releasing the stored energy in response to a scram signal such that the scram gas expands into the chamber of the scram accumulator to compress the bellows and expel the scram liquid from the scram accumulator to insert control rods into a core of the nuclear reactor.

Abstract: Inspection devices nondestructively sense component shape and integrity such as through ultrasonic sensors. Inspection devices include a positional determinator to give orientation of devices relative to the tested object. True distances and relative boundaries of the object are determined with testing and orientation data regardless of rigid or known inspection device position. Inspection data can be corrected for refraction knowing distances and object boundaries. Inspection devices can include additional inspection components like cameras and lighting to match visual inspection with nondestructive testing data spatially and temporally. Inspection devices can be used with self- or manual-propulsion in a working environment with the inspection object. Inspection devices use an operator or computer processor, local or remotely-connected power sources, and communications structures to power and operate the devices.