Abstract: A passive venting arrangement for use in venting of gases produced by radioactive materials includes a source gas region for receiving the gases produced by the radioactive materials; a filter ullage region disposed above the source gas region and segregated therefrom except for a plurality of bore holes which each extend between, and fluidly couple, the source gas region and the filter ullage region; and a plurality of filters disposed in contact with the filter ullage region, wherein each filter is structured to provide for the exchange of gases from the filter ullage region through the filter to an ambient environment.

Abstract: A fuel assembly for use in a nuclear reactor comprising a fuel bundle, a plenum header connection positioned on the fuel bundle, a mast extending from the fuel bundle, and a common fission gas plenum extending from the mast is disclosed. The reactor includes a vessel and coolant situated within the vessel. The fuel bundle comprises a plurality of fuel elements including nuclear fuel material positioned therein. The plenum header connection comprises a plurality of passageways defined therein that are in fluid communication with the nuclear fuel material. The elongate mast comprises an internal passage connecting the common fission gas plenum to the plurality of passageways of the plenum header connection such that the common fission gas plenum is configured to receive an amount of fission gas generated by the nuclear fuel material during operation. The common fission gas plenum is positioned in an otherwise unused portion of the vessel.

Abstract: A nuclear containment atmospheric filter including dedicated piping, valves, a control system and a chemical injection system to facilitate the use of a commercial nuclear power plant's Spent Fuel Storage Pool and Spent Fuel Storage Pool Cooling System to filter and cool contaminated air and steam vapor released from within a Reactor Containment Vessel/Building preventing vessel overpressure and radioactive release.

Abstract: A debris filtering skirt configured for use with a flow plate of a bottom nozzle of a nuclear reactor is disclosed herein. The debris filtering skirt includes a base portion defining an opening between a bottom edge and a reactor vessel lower core plate, and the opening includes a dimension configured to position the bottom nozzle a predetermined distance away from the reactor vessel lower core plate. The debris filtering skirt also includes a plurality of holes, and at least one hole of the plurality of holes includes a dimension determined based, at least in part, on a predetermined size of debris capable of traversing through the inlet and the outlet. The dimension of the opening and the dimension of the at least one hole are determined based, at least in part, on a predetermined loss coefficient of the bottom nozzle.

Abstract: Arrangements and devices for reducing and/or preventing wear of a thermal sleeve in a nuclear reactor are disclosed. Arrangements include a first structure provided on or in one the thermal sleeve and a second structure provided on or in the head penetration adapter. At least a portion of the first structure and at least another portion of the second structure interact to resist, reduce, and/or prevent rotation of the thermal sleeve about its central axis relative to the head penetration adapter. Devices include a base for coupling to a guide tube of the reactor and a plurality of protruding members extending upward from the base. Each member having a portion for engaging a corresponding portion of a guide funnel of the thermal sleeve.

Abstract: A method of decontaminating an object removed from a nuclear power plant utilizing a decontamination system is disclosed. The decontamination system includes a platform, an imaging system, a robotic arm including an end effector configured to discharge a decontamination medium, and a control system operably coupled to the imaging system and the robotic arm. The method includes placing the object on the platform, scanning, by the imaging system, the object, generating, by the control system, a three-dimensional model of the object based on the scanned object, planning, by the control system, a decontamination path based on the generated three-dimensional model, controlling, by the control system, a position of the robotic arm according to the planned decontamination path, and discharging, by the end effector, the decontamination medium onto the object at a plurality of positions along the planned decontamination path.

Abstract: A rotation apparatus is usable with a control drum in a nuclear environment. The control drum is situated on a shaft that is rotatable about a horizontal axis of rotation, and the control drum includes an absorber portion and a reflector portion. The rotation apparatus includes a rotation mechanism that is structured to apply to the shaft in an operational position a force that biases the shaft to rotate toward a shutdown position, with the force being resisted by a motor to retain the shaft in the operational position when the motor is powered. The force is not resisted when the motor is unpowered. The rotation apparatus further includes a rotation management system that controls the rotation of the shaft.

Abstract: Methods of manufacture for nuclear batteries are provided. The method comprises inserting a radiation source material into a cavity defined within a first component to form a radiation source layer. The first component comprises a first electrical insulator layer defining the cavity and a first casing layer disposed over the first electrical insulator layer. The method comprises contacting the first casing layer with a second casing layer of a second component to form an assembly. The second component comprises a second electrical insulator layer and the second casing layer disposed in contact with the second electrical insulator layer. The method comprises swaging the assembly to form the nuclear battery.

Abstract: An annular nuclear fuel pellet in combination with an inserted discrete neutron absorber. The pellet/absorber may be compatible with existing or future nuclear fuel assembly designs. The concept involves the use of nuclear fuel (e.g., uranium dioxide or uranium silicide) formed into annular fuel pellets which can then have a discrete absorber material inserted into the center of the pin. Preferably, the discrete absorber is a non-parasitic absorber. The resulting pellet/absorber can then be stacked into a fuel rod which is arranged in a nuclear fuel assembly. Dimensioning of the annular pellet and absorber and selection of the absorber material and density can allow the concept to be tailored for various nuclear fuel applications.

Abstract: A process is described that includes forming a metal alloy component having a pre-specified three dimensional geometry for use in a nuclear reactor by an additive manufacturing process followed by annealing the formed component at a first annealing temperature within the alpha temperature range of the phase diagram for the metal alloy. A second annealing step at a second annealing temperature lower than the first annealing temperature may be added. Alternatively, annealing may be at an annealing temperature in the alpha+beta temperature range of a phase diagram for the metal alloy, followed by a second anneal in the alpha temperature range of the phase diagram for the metal alloy.

Abstract: A method whereby signals that are output by replacement SPNDs are converted into equivalent signals that would have been detected by legacy SPNDs for input to the legacy software. The replacement SPNDs have a different geometry than the legacy SPNDs and also have a different neutron sensitivity than the legacy SPNDs. The replacement SPNDs are subjected to a neutron flux in a core of a reactor and responsively output a set of signals. The set of signals and the geometry of the replacement SPNDs are employed to create a characterization of the neutron flux in the form of a curve that represents flux as a function of location along the core of the reactor. The legacy geometry of the legacy SPNDs is then employed to find the values on the curve that correspond with the positions where the legacy SPNDs had been located to create inputs for the legacy software.

Abstract: A reactor unit cell is disclosed including a graphite moderator structure, a heat pipe positioned in the graphite moderator structure, and a fuel assembly positioned in the graphite moderator structure. The fuel assembly comprises a beryllium-oxide sleeve and nuclear fuel positioned in the beryllium-oxide sleeve.

Abstract: Disclosed is a diagnostic apparatus structured to be electrically connected with a coil stack of a drive mechanism of a control device of a nuclear reactor. The coil stack has a plurality of coils. The diagnostic apparatus includes a power supply and a controller including a processor and a memory that stores a number of routines including a number of instructions. When executed on the processor the instructions cause the diagnostic apparatus to apply to a coil a voltage that varies as a function of time, detect a current in the coil as a function of time, identify in the current a first inflection point and a second inflection point, and determine, based upon an electronic evaluation that includes the first inflection point and the second inflection point, that the coil is one of functioning properly and in a state of at least partial failure.

Abstract: Systems and methods for the remote control of automated equipment are disclosed herein. The systems and methods include automated equipment configured to execute a process in a restricted location by performing operations based on predetermined programming. In some embodiments, the process is a welding process and the restricted location is a nuclear containment building. The system and methods also include cellular routers configured to enable communication of operating parameters between the automated equipment and a human machine interface (HMI). An operator is able to remotely modify operations of the automated equipment, without being inside of or at the site of the restricted location, by changing the operating parameters using the HMI.

Abstract: A device configured to measure radioactivity emitted by a plurality of radionuclides is disclosed herein. The device includes a gamma detector and a source cage with an outer ring that defines a volume and includes an orientation feature and a plurality of holes configured to receive a radionuclide of the plurality of radionuclides. The device also includes a frame that includes an arm and a central rod, wherein the arm is configured to be coupled to the outer ring and includes an orientation pin. The central rod can be positioned relative to the volume when the arm is coupled to the outer ring of source cage. The orientation feature of the source cage is configured to engage the orientation pin of the arm and, when the orientation pin engages the orientation feature, the central rod is in a predetermined location relative to the volume.

Abstract: Disclosed are a radioisotope activity surveillance system and methods. The system includes a fuel rod assembly having a plurality of nuclear fuel rods and a target assembly having a top nozzle including an orifice plate and at least one target material rod fixedly coupled to the orifice plate. The least one target material rod is slidably disposed within the fuel rod assembly. A sensing assembly defines an opening sized and configured to receive the target assembly therethrough. The sensing assembly includes a self-powered detector assembly to detect radioisotope activity of the target rod material. Also disclosed is a method for measuring a self-powered detector signal to calculate radioisotope activity of a target assembly and a method for analyzing total activity of a desired radioisotope.

Abstract: A dry cask storage system for spent nuclear fuel includes a detection apparatus having a resonant electrical circuit, with resonant electrical circuit being situated within an interior region of a metallic vessel wherein the SNF is situated. The detection apparatus includes a transmitter that generates an excitation pulse that causes the resonant circuit to resonate and to generate a response pulse. The resonant circuit includes an inductor that is formed with a core whose magnetic permeability varies with temperature such that the frequency of the resonant circuit varies as a function of temperature. The response pulse is then used to determine the temperature within the interior of the vessel where the SNF is situated. Pressure detection is also provided.

Abstract: Disclosed are a voltage drop measurement system and methods for measuring resistivity of a nuclear reactor cladding. The system includes a short cladding sample of a nuclear reactor cladding. Two electrically conductive plugs are attached to the short cladding. A power supply is electrically coupled to the each of the two electrically conductive plugs and is configured to apply an electrical current to the short cladding through the two electrically conductive plugs. Two needle like probes are electrically coupled to a surface of the short cladding between the two electrically conductive plugs. The needle like probes are spaced apart by a distance L. Resistivity and heat flux are determined in accordance with Equations (1)-(4).

Abstract: A method that produces high energy charged particles that may be used to destroy cancer cells contained in cancerous tissues. The device uses electronic neutron generators to produce neutrons with energies that have a high probability to interact with a therapeutic source comprised of a reactive material with an outer layer of a material having a high atomic number such as Platinum or Gold. The reaction produces high energy electrons, and in some cases other charged particles with relatively short half-lives, which can destroy the cancerous cells, without seriously damaging the surrounding healthy tissue.

Abstract: A device configured to measure radioactivity emitted by a plurality of radionuclides is disclosed herein. The device includes a gamma detector and a source cage with an outer ring that defines a volume and includes an orientation feature and a plurality of holes configured to receive a radionuclide of the plurality of radionuclides. The device also includes a frame that includes an arm and a central rod, wherein the arm is configured to be coupled to the outer ring and includes an orientation pin. The central rod can be positioned relative to the volume when the arm is coupled to the outer ring of source cage. The orientation feature of the source cage is configured to engage the orientation pin of the arm and, when the orientation pin engages the orientation feature, the central rod is in a predetermined location relative to the volume.