Patent application number | Description | Published |
20090052607 | Spacer Grid for Close-Spaced Nuclear Fuel Rods - A spacer grid can be applied to close-spaced nuclear fuel rods. The spacer grid is directed to solve the problem in which, as the outer diameter of each nuclear fuel rod increases due to the use of dual-cooled nuclear fuel rods for improving cooling performance and obtaining high combustion and high output power, the gap between the neighboring nuclear fuel rods is narrowed to thus make it impossible to use an existing spacer grid. The spacer grid is a combination of unit grid straps, each of which has supports for supporting each of the nuclear fuel rods set in a narrow array and has a sheet shape, which are combined with each other. The supports are located at positions shifted from the longitudinal central line of each unit grid strap toward sub-channels. | 02-26-2009 |
20100128835 | INTERMEDIATE END PLUG ASSEMBLY FOR SEGMENTED FUEL ROD AND SEGMENTED FUEL ROD HAVING THE SAME - An intermediate end plug assembly for a segmented fuel rod can stably support the fuel rod to the end of its cycle even if an interval between the fuel rods becomes narrow due to application of a dual-cooled fuel rod, and reduce excess vibration induced by flows of interior and exterior channels of the dual-cooled fuel rod for obtaining high burnup and output. To this end, the fuel rod has a segmented structure so as to make its length short. A lower intermediate end plug includes at least one channel hole, through which a coolant flows into an internal channel of the fuel rod, so that a possibility of causing departure from nuclear boiling ratio (DNBR) of the dual-cooled fuel rod is reduced. | 05-27-2010 |
20100142668 | POROUS PLENUM SPACER FOR DUAL-COOLED FUEL ROD - A porous plenum spacer is inserted into the plenum of a dual-cooled fuel rod having concentric inner and outer cladding tubes. The porous plenum spacer includes a hollow cylindrical body inserted into the annular space between the inner and outer cladding tubes. The hollow cylindrical body includes a plurality of through-holes formed in an outer circumference thereof or at least one groove formed in one of outer and inner circumferences thereof in a lengthwise direction. Pores formed by the through-holes or the grooves of the hollow cylindrical body of the porous plenum spacer are allowed to secure a space containing fission gas inevitably generated by a nuclear reaction. | 06-10-2010 |
20100172460 | PERFORATED PLATE SUPPORT FOR DUAL-COOLED SEGMENTED FUEL ROD - A perforated plate support supports dual-cooled fuel rods, each of which has concentric outer and inner tubes and is coupled with upper and lower end plugs at upper and lower ends thereof, and guide thimbles, each of which is used as a passage for a control rod. The perforated plate support is formed as a support plate having the shape of a flat plate, which includes internal channel holes, each of which has a diameter corresponding to an outer diameter of the inner tube, guide thimble holes, each of which has a diameter corresponding to an outer diameter of the guide thimble, and sub-channel holes around each internal channel hole. The upper or lower end of the dual-cooled fuel rod is coupled to the support plate such that the outer diameter of the inner tube is matched with the diameter of the internal channel hole. | 07-08-2010 |
20110051882 | TRUSS-REINFORCED SPACER GRID AND METHOD OF MANUFACTURING THE SAME - A truss-reinforced spacer grid and a method of manufacturing the same are provided, in which truss members having a small diameter are woven to form a truss structure surrounded by an external plate, and the truss structure is joined to the external plate to thereby improve the strength of the mechanical structure. The truss-reinforced spacer grid includes a truss structure in which horizontal trusses formed by horizontally weaving a plurality of truss members are vertically disposed at regular intervals, and an external plate is joined with ends of the horizontal trusses and surrounds the truss structure. | 03-03-2011 |
20110064184 | UNIT SPACER GRID STRAP, UNIT SPACER GRID, AND SPACER GRID FOR NUCLEAR FUEL RODS - A spacer grid for nuclear fuel rods includes a plurality of unit spacer grids stacked one on top of another. Each unit spacer grid includes a plurality of unit spacer grid straps disposed at regular intervals in a row, and a plurality of fixing grid straps connected to respective opposite ends of the unit spacer grid straps so as to fix the unit spacer grid straps. Each unit spacer grid strap has convexities alternating with each other on opposite sides thereof at regular intervals, and at least one of the convexities has a diameter greater than the others. The unit spacer grids are rotated in one direction by a 90 or 180 degree angle when being stacked. | 03-17-2011 |
20120063562 | DUAL-COOLED FUEL ROD'S SPACER GRIDS WITH UPPER AND LOWER CROSS-WAVY-SHAPE DIMPLE - A dual-cooled fuel rod's spacer grid with upper and lower dimples, including a blocking area of a flow passage that coolant flows through is reduced and dual-cooled fuel rods are supported, and reduces a turbulent flow of the coolant as well as vibrations of the dual-cooled fuel rods, thereby lessening fretting damage done to the rods. The spacer grid includes a plurality of unit grid straps, each of which includes a body disposed in a vertical direction, an upper dimple protruding from an upper portion of the body, and a lower dimple spaced apart from the upper dimple in a downward direction and protruding from a lower portion of the body. The unit grid straps form a grid structure that have inner grid holes into which the dual-cooled fuel rods are held, and the held dual-cooled fuel rods are each supported in four directions by the upper and lower dimples. | 03-15-2012 |
20130259188 | REVERSE CONICAL LOWER END PLUG FOR AN ANNULAR NUCLEAR FUEL ROD - A lower end plug for an annular nuclear fuel rod includes a support with a great slenderness ratio, a coolant inflow part with an inner inflow space and a plurality of inflow holes in a wall thereof so as to interact with the inflow space, coupled to a lower end of the annular nuclear fuel rod at an upper end thereof, and extending from an upper end of the support in a reverse conical shape such that the inflow space interact with an inner channel of the annular nuclear fuel rod, and a coupler extending from a lower end of the support and coupled with a handing tool of the annular nuclear fuel rod. Thus, although a bottoming phenomenon of the annular nuclear fuel rod occurs, the coolant can be supplied to the inner channel of the annular nuclear fuel rod through the inflow holes of the lower end plug. | 10-03-2013 |