Abstract: An auxiliary feedwater valve control apparatus of a steam generator that operates an auxiliary feedwater valve in an auxiliary feed water system provided as a protective system of a main feed water system that feeds secondary cooling water to a steam generator, includes a water-level detection means that detects a water level of secondary cooling water in the steam generator, a water-level-deviation calculation means that calculates a deviation between a preset target water level and a water level detected by the water-level detection means, a valve-operation setting means that sets an aperture of the auxiliary feedwater valve corresponding to a deviation of the water level, and a valve drive means that outputs a signal for driving the auxiliary feedwater valve corresponding to setting by the valve-operation setting means.

Abstract: A neutron generator includes an ion source disposed in a pressurized environment containing an ionizable gas. The ion source includes a substrate with a bundle of carbon nanotubes extending therefrom. The ends of the nanotubes are spaced from a grid. Ion source voltage supply circuitry supplies a positive voltage potential between the substrate and the grid of the ion source to cause ionization of the ionizable gas and emission of ions through the grid. An ion accelerator section is disposed between the ion source and a target. The ion accelerator section accelerates ions that pass through the grid towards the target such that collisions of the ions with the target cause the target to generate and emit neutrons therefrom. The ion source, accelerator section and target are housed in a sealed tube and preferably the carbon nanotubes of the bundle are highly ordered with at least 106 carbon nanotubes per cm2 that extend in a direction substantially parallel to the central axis of the tube.

Abstract: A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

Abstract: An underwater remote inspection device is provided with an etching device and a magnifying observation device mounted to a supporting member. A chamber of the etching device is provided with a negative electrode, a positive electrode and a sealing device, and is connected to an etchant supply pipe and an etchant exhaust pipe. A single pair of annular sealing members of the sealing device is provided to a distal end portion of the chamber. A suction passage formed in the side wall of the chamber communicates to a sealing region formed between the sealing members. The magnifying observation device is provided with a magnifying camera in a waterproof container and a plurality of LED lights are installed to the waterproof container. The underwater remote inspection apparatus can prevent leakage of an etchant and reduce execution time of etching.

Abstract: A passive containment air cooling system for a nuclear power plant that enhances air flow over a metal containment that houses the reactor system to improve heat transfer out of the containment. The heat transfer is improved by employing swirl vanes to mix the air as it rises over the walls of the containment due to natural circulation and a vortex engine proximate an exit along the cooling air path to increase the quantity of air drawn along the containment.

Abstract: A treatment of a heater tube intended to be used in a pressurizer of the primary cooling system of a nuclear reactor. In particular, the heater tube comprises a heater housed in a substantially cylindrical sheath. The material of which this sheath is made is a work-hardened austenitic stainless steel. In particular, the external surface of the sheath is liable to undergo a stress corrosion during use of the heatertube. The method includes a heat treatment step, preferably using induction heating, in which the external surface of the sheath is heat-treated so as to recrystallize the material of the sheath at least on the surface thereof.

Abstract: A laser inertial-confinement fusion-fission energy power plant is described. The fusion-fission hybrid system uses inertial confinement fusion to produce neutrons from a fusion reaction of deuterium and tritium. The fusion neutrons drive a sub-critical blanket of fissile or fertile fuel. A coolant circulated through the fuel extracts heat from the fuel that is used to generate electricity. The inertial confinement fusion reaction can be implemented using central hot spot or fast ignition fusion, and direct or indirect drive. The fusion neutrons result in ultra-deep burn-up of the fuel in the fission blanket, thus enabling the burning of nuclear waste. Fuels include depleted uranium, natural uranium, enriched uranium, spent nuclear fuel, thorium, and weapons grade plutonium. LIFE engines can meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the highly undesirable stockpiles of depleted uranium, spent nuclear fuel and excess weapons materials.

Abstract: A neutron generator includes a conductive substrate comprising a plurality of conductive nanostructures with free-standing tips and a source of an atomic species to introduce the atomic species in proximity to the free-standing tips. A target placed apart from the substrate is voltage biased relative to the substrate to ionize and accelerate the ionized atomic species toward the target. The target includes an element capable of a nuclear fusion reaction with the ionized atomic species to produce a one or more neutrons as a reaction by-product.

Abstract: Disclosed is a heat exchanger for a passive residual heat removal system, which improves heat transfer efficiency by expanding a heat transfer area. A heat exchange tube includes a first member connected to a steam pipe through which steam generated from a steam generator of a nuclear reactor circulates, and a second member connected to both of the first member and a feed water pipe used to supply water to the steam generator provided in the nuclear reactor, and the first member has the shape different from that of the second member, thereby expanding the heat transfer area so that the heat transfer efficiency is improved.

Abstract: A system and method for storing radioactive waste, such as spent nuclear fuel, in one embodiment, the invention is a method of controlling temperature of a portion of a storage system comprising a container loaded with radioactive waste and a ventilated module in which the container is positioned, the ventilated module configured so that heat generated by the radioactive waste causes a natural convective flow of air through, a ventilation passageway of the ventilated module, the method comprising; throttling the natural convective flow of the air through the ventilated module to alter a heat rejection rate of the storage system to compensate for a decreasing heat generation rate of the radioactive waste to maintain the portion of the storage system within a predetermined temperature range.

Abstract: Disclosed herein is a prompt gamma-ray detection apparatus for analyzing chemical materials using femtosecond pulse laser-induced neutrons, which can be effectively used in the nondestructive inspection of various materials, such as metals, coal, cement, radioactive materials and the like as well as explosives and chemical materials, and which can provide better measurement results for the analysis of basic materials, and a method of measuring prompt gamma-rays using the apparatus. The prompt gamma-ray detection apparatus is advantageous because it can non-destructively analyze the elements in a chemical sample using a femtosecond pulse laser-induced neutron generator that solves the problems of an atomic reactor for research or a radioactive isotope as a neutron radiation source.

Abstract: A telescoping guide for extraction and reinsertion support handling of in-core instrument thimble assemblies in the area above the upper support plate in the upper internals of a pressurized water reactor. The telescoping guides extend between the upper ends of the upper internals support columns and an axially movable instrumentation grid assembly which is operable to simultaneously raise the telescoping guides and extract the in-core instrument thimble assemblies from the reactor fuel assemblies.

Abstract: A method and system for detecting special nuclear materials are disclosed. Said method and system detect the special nuclear materials by making use of the photofission characteristic and thermal neutron induced fission characteristic thereof. In one preferred embodiment, the high density and/or high atomic number region in the object to be detected is also detected first as a suspicious region.

Abstract: Systems for enhancing preignition conditions of a fusion reaction are disclosed. A first system includes a target chamber for receiving a fusion fuel, and energy driving means oriented to direct plasma confinement structure onto to the fusion fuel to facilitate ignition of a controlled fusion reaction of said fusion fuel. A plurality of electron sources provides electron beams of a predetermined energy and one of fluence and quantity, directed onto and illuminating, a fusion fuel-derived plasma for controlling the ratio of ion temperature and electron temperature of the plasma. A second system comprises a central target chamber for receiving a spherical pellet of fusion target material and at least first and second pluralities of energy drivers oriented to supply temporally-staged X-ray pulses to the fusion target material in a 3-dimensionally symmetric manner about said pellet. A third system combines aspects of the first and second systems.

Abstract: The invention relates to the field of nuclear technology and radiochemistry, more specifically to the production and isolation of radionuclides for medical purposes. The method for producing actinium-225 and isotopes of radium comprises irradiating a solid block of metallic thorium of a thickness of 2 to 30 mm, which is contained within a hermetically sealed casing made of a material which does not react with thorium, with a flow of accelerated charged particles with high intensity. The irradiated metallic thorium is removed from the casing and is either heated with the addition of lanthanum and the distillation of radium or is dissolved in nitric acid with the recovery of actinium-225 by extraction. A target for implementing this method consists of blocks of metallic thorium of a thickness of 2 to 30 mm, which are contained within a hermetically scaled casing made of different materials which do not react with thorium.

Abstract: A fuel assembly for a pressurized water reactor that has a protective grid attached to the bottom nozzle through a spacer insert captured between a control rod guide thimble end plug and the bottom nozzle. A thimble screw attaches the bottom nozzle to the control rod guide thimble end plug through a central opening in the spacer insert. The control rod guide thimble end plug is provided with a raised annular boss that encircles the thimble screw shank and rests against the upper surface of the bottom nozzle through the opening in the spacer insert. The opening in the spacer insert is large enough to provide both an axial and radial clearance between the spacer insert and the end plug to accommodate differences in thermal expansion.

Abstract: In a method of designing a nuclear reactor core for uprated power operations, a set of constraints are inputted to be satisfied for uprated power operations, and a test reactor core design is generated based on the constraints. One or more automated tools may be selected from a set of automated tools to evaluate the test core design against the constraints. The selected tool may then be operated. Operation of the selected automated tool includes simulating reactor operation with the test core design, based on the constraints, to produce a plurality of outputs, comparing the outputs against the constraints, and providing data indicating constraints that were violated by the test core design during the simulation, based on the comparison. One or more of the automated tools are iterated until a test core design meets all constraints for uprated power operations, thereby representing an acceptable power uprate core design.

Abstract: A compressor assembly and the method of using the same which includes an elongated spiral passageway within which a compact toroid plasma, such as a compact toroid plasma structure, can be efficiently compressed to a high-energy state by compressing the compact toroid plasma structure by its own momentum against the wall of the spiral passageway in a manner to induce heating by conservation of energy. The compressor assembly also includes a burn chamber that is in communication with the spiral passageway and into which the compressed compact toroid plasma structure is introduced following its compression.

Abstract: A method and apparatus for the calibration of neutron flux monitoring devices used in a nuclear reactor core. The apparatus includes a transverse in-core probe (TIP) cable with a neutron absorber located a fixed distance apart from a TIP detector. The neutron absorber may be passed within close proximity of the neutron flux monitoring device such that a perceived drop in measured neutron flux occurs, whereupon the cable may be repositioned relative to the monitoring device to ensure that the TIP detector is within close proximity of the monitoring device for purposes of calibrating the monitoring device.

Abstract: Disclosed is a system for producing electromagnetic radiation with enhancement from a drift tube containing a cylindrical Smith-Purcell structure. The system includes a magnetically insulated linear oscillator. The oscillator includes a cylindrical resonant cavity having a traveling wave electron gun and a cooperating anode. The drift tube is formed of a hollow cylindrical conductive element that is positioned within a resonant cavity of the oscillator. The drift tube includes an inner surface and a pair of ends. The drift tube may be adapted such that the interaction between an electron beam, from the electron gun, passes through the inner space of the drift tube, and the internal grating, so as to produce RF radiation by the Smith-Purcell Effect. Spacing, face angle and shape of the grating, and the energy of the electron beam are determinants of the frequency of the RF radiation.