Patent application number | Description | Published |
20110182394 | TOP NOZZLE FOR NUCLEAR FUEL ASSEMBLY HAVING SPRING INSERT HOLE IMPROVED IN FASTENING STABILITY AND METHOD OF MANUFACTURING THE SAME - A top nozzle for a nuclear fuel assembly and a method of manufacturing the top nozzle are provided. The top nozzle can include a coupling plate, a perimeter wall and a hold-down spring unit. The coupling plate can be coupled to a guide thimble of the nuclear fuel assembly. The perimeter wall can protrude upwards from the perimeter of the coupling plate. A spring clamp can be provided on the upper surface of the perimeter wall. The hold-down spring unit can be mounted to the upper surface of the perimeter wall in such a way to couple a corresponding end of the hold-down spring unit to the spring clamp. A fastening pin hole can be vertically formed through an upper surface of the spring clamp. A spring insert hole into which the hold-down spring unit can be inserted and formed by electro-discharge machining in an insert direction of the hold-down spring. | 07-28-2011 |
20110182395 | HOLD-DOWN SPRING UNIT FOR TOP NOZZLE OF NUCLEAR FUEL ASSEMBLY HAVING IMPROVED HOLD-DOWN PERFORMANCE AND TOP NOZZLE FOR NUCLEAR FUEL ASSEMBLY HAVING THE SAME - Disclosed herein is a hold-down spring unit for a top nozzle of a nuclear fuel assembly. The hold-down spring unit is coupled to the upper end of the top nozzle of the nuclear fuel assembly. The hold-down spring unit includes a first spring which acts against a hold-down force with respect to the nuclear fuel assembly under start-up conditions or hot full power conditions of a nuclear reactor, and a second spring which acts against a hold-down force with respect to the nuclear fuel assembly under start-up conditions of the nuclear reactor. The present invention reduces the hold-down margin under start-up conditions or hot full power conditions, thus enhancing the mechanical and structural stability of the nuclear fuel assembly. | 07-28-2011 |
20110182396 | GUIDE THIMBLE PLUG FOR NUCLEAR FUEL ASSEMBLY - A guide thimble plug for a nuclear fuel assembly is provided, in which an internal threaded hole is formed through a main body so that the main body is coupled to a bottom nozzle by a screw coupling. An upper insert part is formed in the upper end of the main body. The upper insert part is inserted into a shock absorption tube. A thermal deformation prevention part is formed on the main body below the upper insert part and is recessed inward from the outer surface of the main body such that, when the main body is coupled to the guide thimble, a gap is defined between the thermal deformation prevention part and the guide thimble. The guide thimble and the shock absorption tube can be reliably fastened to the bottom nozzle, and thermal deformation of the guide thimble can be minimized. | 07-28-2011 |
20120246933 | TOP NOZZLE FOR NUCLEAR FUEL ASSEMBLY HAVING SPRING INSERT HOLE IMPROVED IN FASTENING STABILITY AND METHOD OF MANUFACTURING THE SAME - A top nozzle is provided. The top nozzle can include a coupling plate, a perimeter wall and a hold-down spring unit. The coupling plate can be coupled to a guide thimble of the nuclear fuel assembly. The perimeter wall can protrude upwards from the perimeter of the coupling plate. A spring clamp can be provided on the upper surface of the perimeter wall. The hold-down spring unit can be mounted to the upper surface of the perimeter wall in such a way to couple a corresponding end of the hold-down spring unit to the spring clamp. A fastening pin hole can be vertically formed through an upper surface of the spring clamp. A spring insert hole into which the hold-down spring unit can be inserted and formed by electro-discharge machining in an insert direction of the hold-down spring. | 10-04-2012 |
20130003910 | HOLD-DOWN SPRING UNIT FOR TOP NOZZLE OF NUCLEAR FUEL ASSEMBLY, AND TOP NOZZLE FOR NUCLEAR FUEL ASSEMBLY EMPLOYING THE HOLD-DOWN SPRING UNIT - A hold-down spring unit for a top nozzle of a nuclear fuel assembly. The hold-down spring unit is coupled to the upper end of the top nozzle of the nuclear fuel assembly. The hold-down spring unit includes a first spring which provides a hold-down force upon the nuclear fuel assembly under start-up conditions or hot full power conditions of a nuclear reactor, and a second spring which provides an additional hold-down force upon the nuclear fuel assembly under start-up conditions of the nuclear reactor. The hold-down margin under start-up conditions or hot full power conditions is reduced, thus enhancing the mechanical and structural stability of the nuclear fuel assembly. | 01-03-2013 |
Patent application number | Description | Published |
20110294243 | PHOTORESIST COMPOSITION AND METHOD OF FORMING PHOTORESIST PATTERN USING THE SAME - A photoresist composition suitable for forming a high-resolution pattern, and a method of forming a photoresist pattern using the same. The photoresist composition includes about 10 to about 45 parts by weight of an alkali soluble binder resin including a hydroxyl group, about 0.1 to about 5 parts by weight of a photo-acid generator, about 1 to about 5 parts by weight of a cross-linker that cross-links the alkali-soluble binder resin including the hydroxyl group, about 0.3 to about 3 parts by weight of a quinone diazide compound, and a remainder of a solvent. | 12-01-2011 |
20120270142 | PHOTOSENSITIVE COMPOSITION AND METHOD OF MANUFACTURING A SUBSTRATE FOR A DISPLAY DEVICE USING THE SAME - A photosensitive composition and a method of manufacturing a substrate used for a display device are disclosed. The photosensitive composition includes an acrylic based copolymer, a photo-initiator, a photo-sensitizer and a solvent. Thus, a photosensitivity of the photosensitive composition for ultra violet light of a long wavelength may be improved. | 10-25-2012 |
20140234776 | PHOTOSENSITIVE RESIN COMPOSITION AND METHOD OF FORMING PATTERN USING THE SAME - A photosensitive resin composition includes: an acrylic copolymer comprising a polymerization product of a first monomer comprising at least one selected from an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride, and a second monomer comprising an olefin-based unsaturated compound; a photosensitive component comprising at least one 1,2-quinonediazide-5-sulfonic acid ester compound selected from compounds represented by Chemical Formulae 1 to 4; a coupling agent; and a solvent, wherein a total amount of asymmetric compounds in the photosensitive component is greater than or equal to 45 area percent as determined by high performance liquid chromatography: | 08-21-2014 |
Patent application number | Description | Published |
20090060116 | FUEL ROD OF NUCLEAR FUEL ASSEMBLY HAVING VASE-LIKE COMPRESSION SPRING ADAPTED TO INCREASE INTERNAL VOLUME THEREOF - The present invention relates to a fuel rod of a nuclear fuel assembly having a vase-like compression spring adapted to increase the internal volume thereof wherein when the vase-like compression spring is inserted into a cladding tube, it has a relatively smaller volume occupied inside the fuel rod when compared with the existing coil type compression spring, such that the vase-like compression spring can ensure a sufficient space portion receiving the fission gases generated during the operation of the fuel rod, thereby increasing the burn-up performance of the fuel rod and the mechanical integrity thereof. | 03-05-2009 |
20090122947 | Joining Structure Between Top Nozzle and Guide Thimbles In Nuclear Fuel Assembly - Disclosed herein is a joining structure between a top nozzle and guide thimbles in a nuclear fuel assembly, which can prevent a rotation of inner insertion tube bodies when the top nozzle is separated from the nuclear fuel assembly and promote convenience in assembling and disassembling the top nozzle and the guide thimbles. | 05-14-2009 |
20100098208 | Anti-fretting Wear Spacer Grid With Canoe-Shaped Spring - The present invention relates to an anti-fretting wear spacer grid having a plurality of canoe-shaped springs formed thereon, wherein each of the canoe-shaped springs includes: a fuel rod-contacting part having a flat surface having a predetermined longitudinal length so as to have linear contact with the fuel rod; a curved face-connecting part formed on the upper and lower portions of the fuel rod-contacting part; a leg-connecting part formed on the end portion of the curved face-connecting part; and legs each being formed of a plate shape having a predetermined length and connecting the both sides of the leg-connecting part with one unit grid cell surface. | 04-22-2010 |
20100166134 | Top Nozzle Having On-Off Type Of Hold-Down Spring In Nuclear Fuel Assembly - The present invention relates to a top nozzle having on-off type of hold-down springs for a nuclear fuel assembly that has a two-stage elastic section such that a pushing force against the axial movement of the nuclear fuel assembly under normal conditions is optimized and at the same time a suppressing force against a drastic uplifting force of the nuclear fuel assembly under transient conditions is strengthened, and that lowers the elastic coefficients of the springs operating under normal conditions more than those of existing coil springs, thereby providing an optimal pushing force against the nuclear fuel assembly. | 07-01-2010 |
20140037040 | SPACER GRID FOR NUCLEAR FUEL ASSEMBLY FOR REDUCING FLOW-INDUCED VIBRATION - Disclosed herein is a spacer grid for a nuclear fuel assembly. The spacer grid has dimples for supporting fuel rods and is formed from grid strips which are assembled in a lattice shape to form lattice cells. Each grid strip has at least one hole which is formed separately from the dimples. Therefore, when coolant is drawn into the fuel assembly, a pressure difference between opposite sides of the holes is reduced, and friction generated between cut edges of the holes and the coolant reduces the magnitude of the vibration and causes a damping effect, thus reducing flow-induced vibration. The hole formed in the grid strip function to widen the range of the frequency of the flow-induced vibration caused by vortex sheddings formed around the edges of the grid strip, thus reducing the possibility of the generation of resonance with the natural frequency of the spacer grid. | 02-06-2014 |
20140037041 | SPACER GRID FOR NUCLEAR FUEL ASSEMBLY FOR REDUCING HIGH FREQUENCY VIBRATION - Disclosed herein is a spacer grid for a nuclear fuel assembly which is formed from grid strips of an improved structure, thus reducing flow-induced high-frequency vibration. The spacer grid has dimples or grid springs for supporting fuel rods and is formed from a plurality of grid strips assembled in a lattice shape to form lattice cells. Each of the grid strips has at least one slot formed in a planar portion of the grid strip separately from the dimple or grid spring. Therefore, characteristics of the vibration of the spacer grid can be set in a variety of different manners so that flow-induced high-frequency vibration can be reduced. | 02-06-2014 |