The invention relates to devices of nuclear energy, in particular to the structural elements of fuel assemblies from power reactors VVER-1000. Conduit consists of a tube and tip. The pipe is made from a material with a low coefficient of growth. On the tube in increments of step placement grid spacers, at least by their upper end is installed restrictive bushing. The technical result - improving the reliability of fuel assemblies. 1 Il.The invention relates to devices of nuclear energy, in particular to the structural elements of fuel assemblies from power reactors VVER-1000.Known guide channels (see U.S. patent No. 4687619, MKI G 21 19/20, 1987, evidence of the Russian Federation No. 6937, MKI G 21 3/04, 1995, testimony of the Russian Federation No. 8514, MKI G 21 3/04, 1998), consisting of the pipe, the gripping sleeve and tip.A disadvantage of the known solutions is the lack of devices preventing displacement and deformation during operation under the action of loads, the spacer grids of the fuel Assembly.The closest in technical essence and the achieved achiev the pipe, the gripping sleeve, the tip, the lack of which is the lack of devices preventing displacement and deformation during operation under the action of loads, the spacer grids of the fuel Assembly.An object of the invention is to improve the operational reliability of the fuel assemblies.The problem is solved in that in the guide channel, consisting of a tube and tip according to the invention, the pipe made of a material with a low coefficient of radiation-induced growth increments step placement grid spacers, at least from their upper set of restrictive sleeve.This set of features is new and involves an inventive step because the execution pipe channel from a material with a low coefficient of radiation growth, eliminate unacceptable lengthening during operation and improves the reliability of fuel assemblies, due to the reduction of their bending, in addition, eliminates the offset grid spacers under the action of loads during operation of the fuel assemblies.The drawing shows the guide channel. The guide channel socioeconomica 2, used to connect the guide channel with the lower part of the fuel Assembly, the pipe 1 is placed in a restrictive bushing 3, the number of which is at least equal to the number of grid spacers. Mount bushing 3 to the pipe 1 is carried out, for example pin-point welding. On the sleeve 3 to simplify its Assembly and welding of the guiding channel in the zone of weld seams can be performed longitudinal section 4.Conduit is an integral part of the fuel Assembly and is intended for the perception of the mechanical loads acting on the Assembly in the course of its operation, place the rod control system and protection. Increasing the length of the guide channel under the action of radiation exposure leads to its curvature. In the worse conditions of safe operation of fuel assemblies.The presence of restrictive bushing 3 eliminates the displacement and deformation of the grid spacers under the action of loads encountered during operation of fuel assemblies, which increases the operational reliability of the fuel assemblies. To reduce the specific pressure in the contact zone of restrictive sleeves with distantsionno the resistance to the flow of fluid, restrictive sleeve in the zone of contact with the spacer bars may have a thickness greater than the area of the weld seams. Specific parameter values restrictive bushings are determined experimentally depending on the design characteristics of the channel (material, diameter, wall thickness), grid spacers, and the minimum hydraulic resistance of the fluid.
ClaimsConduit containing tube to the handpiece, wherein the pipe is made from a material with a low coefficient of radiation-induced growth increments step placement grid spacers, at least by their upper end is installed restrictive bushing.
FIELD: nuclear power engineering; fuel rods for water-moderated water-cooled reactors.
SUBSTANCE: proposed fuel rod designed for use in water-cooled water-moderated power reactors such as type VVER-1000 reactor has fuel core disposed in cylindrical can. Outer diameter of fuel rod is chosen between 7.00 . 10-3 and 8.79 . 10-3m and fuel core diameter is between 5.82 . 10-3 and 7.32 . 10-3m and mass, between 0.93 and 1.52 kg, fuel core to fuel rod length ratio being between 0.9145 and 0.9483.
EFFECT: reduced linear heat loads and fuel rod depressurization probability, enlarged variation range of reactor power, optimal fuel utilization.
7 cl, 3 dwg
FIELD: fuel cells designed for use in gas-cooled nuclear reactor core.
SUBSTANCE: fuel cell 10 designed for use in gas-cooled nuclear reactor has assembly of two adjacent fuel plates 12a, 12b disposed relative to one another and shaped so that they form channels 14 for gaseous coolant flow. Fuel plates 12a, 12b incorporate elementary fissionable particles, better non-coated ones, implanted in metal matrix. Metal coating may be deposited on both ends of each plate 12a and 12b.
EFFECT: enlarged heat-transfer surface, enhanced power density per volume unit.
13 cl, 5 dwg, 1 tbl
FIELD: nuclear power engineering; production of fuel elements for fuel assemblies of nuclear power reactors.
SUBSTANCE: proposed device incorporating provision for discharging cans without damage to fuel pellets and pollution of environment with uranium dioxide dust has fuel pellet collectors installed on end opposing that where pellet charging cradles are abutting against horizontal beds; these collectors are made in the form of removable tanks with covers and with longitudinal slots in their bottoms that follow shape of bosses at seating points and are provided with vacuum-system tubes which join together as soon as removable tank occurs on seating place. Removable tank has hole for passing open end of faulty charged can into removable tank that has sealing ring made of flexible material such as rubber.
EFFECT: enlarged functional capabilities and environmental friendliness of device.
2 cl, 3 dwg
FIELD: core members of nuclear reactors using liquid-metal primary coolant.
SUBSTANCE: proposed nuclear-reactor core fuel assembly has fuel elements, bottom and top spacer grids, splinting wire, and hexagonal tube with bottom nozzle. The latter has outer thread on its cylindrical part and is provided with hold-down nut. Bottom spacer grid is provided with perforated thrust ring and is split through height into two parts joined together. Slots are milled in bottom part of spacer grid along hole axes to pass fuel element splinting wire.
EFFECT: enhanced manufacturability and operating reliability.
1 cl, 2 dwg
FIELD: nuclear power engineering; fuel elements for water cooled and water moderated nuclear reactors.
SUBSTANCE: proposed guide channel for fuel assemblies primarily used for type VVER-1000 reactors has tube and tip. The latter is essentially prefabricated structure. One part of mentioned structure is welded to tube on one of its ends disposed under outer surface of tube. Maximal diameter of tip external part welded to tube is not less than outer diameter of tube and diameter of metal portion disposed between tube end and maximal-diameter part of tip deformed in the course of welding.
EFFECT: enhanced manufacturability and performance characteristics of guide channel.
1 cl, 1 dwg
FIELD: physics; heating.
SUBSTANCE: invention can be applied for manufacturing structure elements and, in particular, fuel assemblies of power reactors of PWR-1000 type. Guide channel of nuclear reactor fuel assembly assemblages contains pipeline, tip and pickup sleeve, the pipeline located at its different ends and weld-seamed to it having ring cavity within weld seam area. Minimum width of welded seam within pickup sleeve alloying with external surface of pipeline is greater or equal to pipeline wall thickness. Minimum size of welded seam net section is greater or equal to one forth of pipeline wall thickness.
EFFECT: improved reliability of channel design.
SUBSTANCE: ingot 1 of big size - with diameter of 400-700 mm and length of 2-3 m is produced by means of casting. Forging of ingot 1 for fabricating semi-finished product 3 is performed in two stages. The first stage of forging ingot 1 is carried out at temperature corresponding to region of existing of α- and β-phases. Temperature of forging can be for example within range from 850°C to 950°C. Fabricated semi-finished products are used for production of tube component of fuel assembly out of rod or stock such as tube shell or guiding tube of fuel assembly of nuclear reactor cooled with water or component of fuel assembly of CANDU reactor and also for producing rod of smaller diameter for plugs, closing ends of tube shells of rods of fuel assemblies of nuclear reactors.
EFFECT: invention facilitates simplification and reduction of cost of items fabrication.
10 cl, 1 dwg
SUBSTANCE: ingot with diameter of 400-800 mm and length of 2-3 m is produced by means of casting; then ingot is forged in one operation at temperature corresponding to region of α- and β-phases of alloy. Flat items are fabricated out of semi-finished product of 0.2-4 mm thickness such as plate of cross grating-bridge of nuclear fuel reactor assembly cooled with water under pressure, or wall of the case of fuel reactor assembly cooled with boiling water or element of fuel reactor assembly CANDU.
EFFECT: invention allows to simplify and reduce cost of items fabrication, also to reduce hydrides contents in semi-finished product.
5 cl, 2 dwg
FIELD: metallurgy, processes.
SUBSTANCE: invention can be used for manufacturing of elements of fuel assembly of nuclear power plant - body or reactor lattice on boiling water, and also reactor lattice with water under the pressure, received from zirconium alloy, consisting not less then 95 wt % of zirconium. Plate work piece made of zirconium alloy is hardened in β-area with receiving of acicular structure receiving, rolling with route without intermediate softening at temperature from room till 200°C and reduction ratio 2-20% and annealed in α- or α+β- area at temperature 500-800°C during from 2 minutes till 10 hours. Cooling rate while tempering in β-area is no less than 1°C/s.
EFFECT: blanks allows at the same time well mechanical properties and low ability to increase dimensions under irradiation.
17 cl, 4 tbl, 6 dwg
FIELD: physics, nuclear physics.
SUBSTANCE: invention relates to the atomic industry and can be used in plants for making fuel assemblies mainly of the type water-moderated water cooled power reactor for APP. Method includes the assembly of channel pipes with capturing bushing, turning to the zone of seam welding. Subsequent welding it with the pipe slot weld, where the turning on the capturing bushing is carried out with the thickness of the walls, equal to 0.3-0.5 of the thickness of the channel pipes, and width from two to three times of this walls. Assembly of bushing with the pipe is carried out with a gap of not more than 20% from the thickness of the walls of the turning. Welding is carried out with penetration of the walls of the pipe till 0.8 of its thickness, and the welding is carried out at a speed of 1-1.3 cm/sec, value of the welding current 10-15 mA voltage acceleration 30±1 kilovolts for a period of 18-21 seconds.
EFFECT: developing of an effecient method of making a directing channel.
2 cl, 4 dwg