Abstract: A pellet magazine includes a plurality of pellet bores sized to receive pellets for loading into a fuel rod. A fuel rod loading system includes a plurality of pellet loading stations each designated to load a single pellet type into one or more pellet bores of the pellet magazine, a rod loading station configured to unload pellets from the pellet bores of the pellet magazine into a fuel rod, and a conveyance system configured to transport the pellet magazine to the loading stations and then to the rod loading station in a defined sequence.

Abstract: The invention provides a method of preparing irradiation targets for radioisotope production in instrumentation tubes of a nuclear power reactor, the method comprising the steps of: providing a powder consisting of an oxide of a rare earth metal having a purity of greater than 99% and, optionally, an organic binder; pelletizing the powder and optionally the organic binder to form a substantially spherical green body having a diameter of from between 1 to 10 mm; and sintering the spherical green body in solid phase at a temperature of at least 70 percent of a solidus temperature of the rare earth metal oxide powder and for a time sufficient to form a round sintered rare earth metal oxide target having a sintered density of at least 80 percent of the theoretical density.

Abstract: The present invention relates to combined moderator/target structures that significantly increase the initial energy spectrum of neutrons generated in a nuclear reactor within the thermal range of said spectrum. Said combined moderator/target structures can be applied in all cases, wherein the neutron-capture cross-section of the target—or a certain isotope therein—is at least 2.0 barn for thermal neutrons.

Abstract: Nuclear reactors have very few systems for significantly reduced failure possibilities. Nuclear reactors may be boiling water reactors with natural circulation-enabling heights and smaller, flexible energy outputs in the 0-350 megawatt-electric range. Reactors are fully surrounded by an impermeable, high-pressure containment. No coolant pools, heat sinks, active pumps, or other emergency fluid sources may be present inside containment; emergency cooling, like isolation condenser systems, are outside containment. Isolation valves integral with the reactor pressure vessel provide working and emergency fluid through containment to the reactor. Isolation valves are one-piece, welded, or otherwise integral with reactors and fluid conduits having ASME-compliance to eliminate risk of shear failure. Containment may be completely underground and seismically insulated to minimize footprint and above-ground target area.

Abstract: An assembly for acting on the outer surface of a tube, and corresponding method are provided. The assembly includes a carrier; at least one inspection or maintenance tool; the carrier includes at least one rolling body; an actuator. The carrier further includes a device for connecting the carrier to the tube, arranged so that the tube absorbs at least 50% of the weight of the carrier and the tool.

Abstract: Apparatus for amplifying low level signals within a nuclear plant's containment building, derived from the ex-core nuclear instrumentation system. The system employs vacuum micro-electronic devices in place of conventional pre-amplifier assemblies to position the pre-amplifier assemblies closer to and within the vicinity of the ex-core detector outputs.

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 canister to store spent nuclear fuel in an underground repository includes a first end portion; a second end portion; and a middle portion attachable to the first and second end portions to define an interior volume of the housing that is sized to enclose at least one spent nuclear fuel assembly. The first and second end portions comprise shielding.

Abstract: Embodiments of the present disclosure are directed to systems, components, and methods for transferring canisters containing radioactive material, for example, from a container assembly using a transfer assembly to a horizontal storage module (HSM). Systems in accordance with various embodiments of the present disclosure include, for example, a vertical to horizontal (VTH) transfer station for a canister and method of transfer, a horizontal to horizontal (HTH) transfer station for a canister and methods of transfer, a transport wagon system for transporting a canister to a horizontal storage module (HSM), and an HSM system for long-term storage of a canister.

Abstract: Reactor target assemblies are provided that can include a housing defining a perimeter of at least one volume and Np or Am spheres within the one volume. Reactor assemblies are provided that can include a reactor vessel and a bundle of target assemblies within the reactor vessel, at least one of the target assemblies comprising a housing defining a volume with Np or Am spheres being within the volume. Irradiation methods are also provided that can include irradiating Np or Am spheres within a nuclear reactor, then removing the irradiated spheres from the reactor and treating the irradiated spheres.

Abstract: A submersible system and method for measuring the gas volume fraction in an aerated fluid inside a reactor (1) wherein the aerated fluid comprises a gas dispersed in the form of bubbles in a fluid in the form of a solution, suspension, mixture of liquids or a combination thereof. The submersible system comprises: an open and pass-through gas exclusion device (20) of a variable cross section wherein the inlet opening whereby the fluid enters without gas bubbles towards the opened and through gas bubbles exclusion device (20) is greater than the outlet opening whereby the fluid exits without gas bubbles of the opened and through gas bubble exclusion device (20). The outlet opening abuts with an inlet pipe (23).

Abstract: A magneto-rheological filter/reflector that controls the transmissivity of any form of electromagnetic or particulate radiation through the filter by varying discrete electromagnetic fields across a magneto-rheological fluid. In one embodiment, the filter/reflector controls the rate of the nuclear reaction within the core of a reactor without any moving parts.

Abstract: A valve assembly includes a flange connected to a vessel penetration of a reactor pressure vessel of a nuclear reactor. A valve is disposed inside the flange or protrudes from the flange into the vessel penetration. The valve includes a valve seat and a movable valve member positioned so that pressure inside the reactor pressure vessel urges the movable valve member against the valve seat to close the valve. The valve assembly further includes a plenum having an inlet via which the plenum can be pressurized to apply pressure to the movable valve member that urges the movable valve member away from the valve seat to open the valve. The plenum may be defined in part by a surface of the movable valve member. The valve assembly preferably does not include a valve actuator.

Abstract: Disclosed is a nuclear power plant which drives a Stirling engine by means of heat generated in nuclear power plant safety systems during an accident, uses the resulting power directly or generates electric power so as to supply the power to the safety systems, and thus can improve economic efficiency as well as the reliability of safety systems, such as a passive safety system, by operating the safety systems without an emergency diesel generator or external electric power.

Abstract: A VVER-1000 nuclear fuel assembly having a modified bottom nozzle with chamfers at the upper edge of the frustoconical transition from a hexagonal upper section of the nozzle to the lower circular end that mounts on a lower core support.

Abstract: Fuel assemblies include an outer channel having a physical configuration optimized for a position of the fuel assembly within a core of a nuclear reactor. The position of the fuel assembly with respect to an employed control blade in the nuclear reactor determines if the outer channel may be thickened, reinforced, and/or fabricated of Zircaloy-4 or similar distortion-resistant material, so as to reduce or prevent distortion of the channel against the control blade, or thinned so as to increase water volume and enhance reactivity in the assembly. Reactor cores having configured fuel assemblies include fuel assemblies having different outer channels. Methods include determining operational characteristics of the fuel assembly, including likelihood of being placed directly adjacent to an employed control blade, and physically selecting or modifying the outer channel of the fuel assembly based thereon.

Abstract: Embodiments of a laser system having an extremely large number of small pulsed lasers for irradiating small targets in inertial confinement fusion experiments, high energy density physics experiments, and inertial fusion power plants is more flexible than existing laser systems. Embodiments facilitate finer control of critical features of laser pulses for inertial fusion, as well as significant reduction in development costs and expansion of the community involved in the research relative to existing laser systems. Embodiments produce smooth intensity profiles at the target, large bandwidth that is over two orders of magnitude greater than existing laser systems, and fine control over laser wavelengths, focal properties, temporal pulse shape, and illumination geometry. Properties of each of the small pulsed lasers are individually selectable.

Abstract: A fuel rack for nuclear fuel assemblies includes a base plate and an array of cells for holding fuel assemblies. The array of cells includes: a plurality of first slotted plates slidably interlocked with one another to form a top portion of the array of cells, the plurality of first slotted plates formed of a first material; a plurality of second slotted plates slidably interlocked with one another to form a middle portion of the array of cells, the plurality of second slotted plates formed of a second material, the first and second materials being metallurgically incompatible; and a plurality of third slotted plates slidably interlocked with one another to form a bottom portion of the array of cells, the plurality of third slotted plates formed of the first material and connected to a top surface of the base plate.

Abstract: A method, system, and apparatus are disclosed for liquid lithium first walls for electromagnetic control of plasmas in fusion power reactor environments. In particular, the method involves installing at least one layer of at least one tile on the surface area of the internal walls of the reactor chamber. A portion of the tile(s) facing the interior of the reactor chamber includes a plurality of channels. The method further involves applying an electric charge to the liquid lithium. Further, the method involves circulating the liquid lithium throughout the interior network of the tile(s) to allow for the liquid lithium to flow into the channels and to reach the external surface of the tile(s) that faces the interior of the reactor chamber. In some embodiments, the method also involves installing at least one magnetic coil between the tile(s) and the surface area of the internal walls of the reactor chamber.

Abstract: A target device for a neutron generating device, an accelerator-excited neutron generating device, and a beam coupling method thereof are disclosed. The target device comprises a plurality of solid particles serving as a target body; and a target body reaction chamber for accommodating the solid particles. With the accelerator-excited neutron generating device and the beam coupling method according to the present invention, the solid particles which are being circulated and situated outside the target body reaction chamber are processed, thereby overcoming defects in the prior art such as low-efficiency heat exchange, a short life time, a bad stability and a narrow application range, and achieving the advantages of high-efficiency heat exchange, a long life time, a good stability and a wide application range.