Abstract: Non-destructive testing method may include providing a source material that emits positrons in response to bombardment of the source material with photons. The source material is exposed to photons. The source material is positioned adjacent the specimen, the specimen being exposed to at least some of the positrons emitted by the source material. Annihilation gamma rays emitted by the specimen are detected.

Abstract: The invention relates to a storage device (1) for storing and transporting nuclear fuel assemblies, the device comprising a plurality of adjacent compartments, each having a lateral wall and being capable of receiving a nuclear fuel assembly, the lateral walls being made using notched structural units (6a, 6b) that are stacked and crisscrossed. According to the invention, each unit (6a, 6b) comprises two spaced-apart flats (16, 18) made of a neutrophage material, as well as an intermediate structure (119) situated between the flats (16, 18) and in contact with them.

Abstract: A boiling water reactor includes a reactor pressure vessel; a steam pipe for transporting steam generated in the reactor pressure vessel out from a steam dome positioned at an upper part of the reactor pressure vessel; a high pressure turbine connected to the steam pipe and driven by the steam; a feedwater heater which heats feedwater supplied to the reactor pressure vessel using bleed steam flowing from the high pressure turbine to the feedwater heater; a bleeding valve which adjusts a flow rate of the bleed steam; and a pressure sensor provided in a main steam line including the steam dome and the steam pipe. The boiling water reactor further includes a monitor and control system which controls an opening degree of the bleeding valve based on a magnitude of fluctuating pressure in the main steam line that is detected by the pressure sensor.

Abstract: The invention relates to nuclear engineering and can be used for fuel clusters of nuclear reactors, for distancing and fixing fuel elements, in particular in the fuel clusters of PWR and BWR reactors. The inventive distance lattice comprises cells which are used for mounting the fuel elements or guide channels and are formed by perpendicular crossing plates. Bent blades for mixing a coolant are embodied on the plate edges at the output of said coolant. Each cell is provided with an insertable distancing element for fixing the fuel element. Said invention makes it possible to increase the turning rigidity of the cells and the stability thereof, to simultaneously reduce the size of the fixation of the fuel elements or the guiding channels in the cells and to decrease the hydraulic resistance of the lattice.

Abstract: A fuel support for a nuclear reactor may include: a plurality of fuel support apertures, each fuel support aperture dimensioned for receiving a lower tie plate of a fuel assembly; and a plurality of lumens, each lumen being coupled to a different fuel support aperture. At least one lumen may be configured for attenuating a fluid flow differently than the fluid flow in at least one other of the lumen.

Abstract: A nuclear fuel composition includes a transuranic fuel and a neutron moderator mixed with transuranic fuel. The neutron moderator includes at least one of hafnium or zirconium.

Abstract: A rear door system for transferring hot cell equipment into or out of a hot cell is disclosed. The rear door system of the present invention includes a rear door, which is provided to a rear wall of the hot cell so as to be movable to open or close the rear wall of the hot cell, and a vertical moving table, which is provided at a predetermined position on the lower portion of the front surface of the rear door so as to be movable upwards or downwards. The rear door system further includes a drive unit, which is provided at a predetermined position in the lower end of the rear door to move the rear door, and a stationary working table, which is disposed above the vertical moving table and is fixed in the hot cell in a horizontal orientation. The rear door system further includes a removable table, which is removably coupled at a predetermined position to the stationary working table, and a hot cell crane hook and a service area crane hook, which are respectively provided inside and outside the hot cell.

Abstract: A method and apparatus for the permissive control of a mast and fuel grapple to be used in the movement of reactor fuel components, including fuel assemblies, single blade and double blade guides, to be used in a Boiling Water Reactor (BWR) nuclear reactor. The Permissive Control System reduces the chance of human error associated with the movement of reactor components by assisting in controlling the location (plant coordinate) of the mast for picking-up and dropping-off reactor components, the sequence of reactor component movements, the orientation (angular rotation) of the mast and fuel grapple, the raising and lowering of the grapple, and the opening and closing of the fuel grapple.

Abstract: An emergency core cooling system directly injects emergency core cooling water, which is supplied from a high-pressure safety injection pump or a safety injection tank for a pressurized light water reactor, into a reactor vessel downcomer. A pipe connector is completely removed from between each direct vessel injection nozzle and each injection extension duct installed on an outer surface of the core barrel, which are opposite to each other. An emergency core cooling water intake port, through which the water is injected from each direct vessel injection nozzle, is formed on the surface of each injection extension duct facing an axis of each direct vessel injection nozzle. Thereby, a structure in which a jet of the emergency core cooling water flows into the injection extension ducts is adopted in a hydraulic connection fashion.

Abstract: A boiling water nuclear reactor comprises: a reactor containment vessel including a dry well and a wet well; a vent pipe connecting the dry well and the pressure suppression pool; a gravity-driven water injection pool to hold boric acid aqueous solution; an emergency core water-injection piping system for causing the boric acid aqueous solution in the gravity-driven water injection pool to fall so as to be injected into the reactor pressure vessel in case of reactor accident; a static containment vessel cooling system pool; a static containment vessel cooling system heat exchanger; a dry well connection pipe connecting an upper part of the static containment vessel cooling system heat exchanger and the dry well; and a gas vent pipe for discharging noncondensible gas in the static containment vessel cooling system heat exchanger into the inside of the pressure suppression pool.

Abstract: A nuclear fuel element including a uranium-molybdenum alloy that provides an enhanced reactivity in research, test and radioisotope production nuclear reactors. In this uranium-molybdenum alloy, the uranium is enriched in the isotope 235-U, while the molybdenum is depleted in the isotope 95-Mo. The thus obtained enhanced reactivity provides, depending on the exact use of the fuel element, a requirement for less uranium in the fuel and the use of the fuel elements during a longer period in the reactor.

Abstract: A nuclear reactor includes a reflector and a flow path. The reflector reflects neutrons, contains graphite and a moderator having a smaller moderating power than the graphite, and is sectioned into plural parts along a direction of flow of fuel pebbles. The flow path is surrounded by the reflector, and the fuel pebbles flow through the flow path and undergo nuclear reaction to generate power. Volume ratio of the graphite to the moderator having a smaller moderating power than the graphite in each part of the reflector is determined based on a power distribution in the reactor core in the direction of flow of the fuel pebbles.

Abstract: Example embodiments are directed to tie plate attachments having irradiation targets and/or fuel assemblies having example embodiment tie plate attachments with irradiation targets and methods of using the same to generate radioisotopes. Example embodiment tie plate attachments may include a plurality of retention bores that permit irradiation targets to be contained in the retention bores. Irradiation targets may be irradiated in an operating nuclear core including the fuel assemblies, generating radioisotopes that may be harvested from the spent nuclear fuel assembly by removing example embodiment tie plate attachments.

Abstract: A nuclear power plant and method of operation for augmenting a second reactor thermal power output in a second operation cycle to a level larger than a first reactor thermal power output in the previous operation cycle. The plant is equipped, for example, with a reactor; a steam loop comprising high and low pressure turbines; a condenser for condensing steam discharged therefrom the low pressure turbine; a feedwater heater for heating feedwater supplied from the condenser; and a feedwater loop for leading feedwater discharged from the feedwater heater to the reactor. The operation method includes decreasing a ratio of extraction steam which is led to the feedwater heater from a steam loop in the second operation cycle.

Abstract: The present invention provides a system and method for a system for accommodating a solid target in an accelerator. The system and method includes a target changer having at least one port for accommodating the solid target, an insert for receiving the solid target in the target changer, a piston for providing a vacuum and a cooling system for the solid target, a cylinder for displacing the piston in one of three positions; and a bracket for securing the insert, piston and cylinder to the target changer.

Abstract: An instrument removal system for removing detector cables from a nuclear reactor includes a removal cart and a disposal cask. in an exemplary embodiment, the removal cart includes a base including a plurality of wheels coupled thereto, a motor mounted on the base, and a drive shaft operatively coupled to the motor. A disposal spool is removably mounted on the drive shaft, and the disposal spool includes a notch sized to receive the detector cable. A housing is mounted on the base, with the housing enclosing the disposal spool. Also, an entrance port is located in the housing to permit the detector cable to enter the housing.

Abstract: The present invention provides a nuclear fuel assembly, where a boron-containing compound is used as a burnable poison and is distributed in a majority of the rods in the assembly. The assembly comprises a plurality of fuel rods, each fuel rod containing a plurality of nuclear fuel pellets, wherein at least one fuel pellet in more than 50% of the fuel rods in the fuel assembly comprises a sintered admixture of a metal oxide, metal carbide or metal nitride and a boron-containing compound.

Abstract: Disclosed is an advanced process that relates to the enhanced production of energy using the integration of multiple thermal cycles (Brayton and Rankine) that employ multiple fuels, multiple working fluids, turbines and equipment. The method includes providing a nuclear reactor, reactor working fluid, heat exchangers, compressors, and multiple turbines to drive compressors that pressurize a humidified working fluid that is combusted with fuel fired in at least one gas turbine. The turbine(s) provide for electrical energy, processes or other mechanical loads.

Abstract: The invention relates to a storage device (1) for the storing and/or transporting of nuclear fuel assemblies, including a plurality of adjacent housings each having a lateral wall and being able to receive a nuclear fuel assembly, the lateral walls being realized at least in part using stacking and intercrossing slotted structural assemblies (6a, 6b), each structural assembly including at least one plate (22) realized in a first material comprising aluminum. According to the invention, each structural assembly (6a, 6b) further includes a tubular cross-section element (20) inside of which is located said at least one plate (22), this tubular cross-section element (20) being realized in a second material selected from steels and titanium and alloys thereof.

Abstract: The present invention provides a system and method for a system for accommodating a solid target in an accelerator. The system and method includes a target changer having at least one port for accommodating the solid target, an insert for receiving the solid target in the target changer, a piston for providing a vacuum and a cooling system for the solid target, a cylinder for displacing the piston in one of three positions; and a bracket for securing the insert, piston and cylinder to the target changer.