摘要:
A method for fabricating a sintered duplex nuclear fuel pellet includes the steps of: preparing a first powder composed of a material selected from the group consisting of UO2 and UO2—Er2O3, and a second powder composed of UO2—Gd2O3 and a sintering additive; producing a duplex compact consisting of an annular outer portion composed of the first powder and a cylindrical inner portion composed of the second powder; and sintering the duplex compact under a reducing gas atmosphere, wherein the sintering additive contains manganese of 0.001% to 2% by weight based on the total weight of the cylindrical inner portion.
摘要:
The present invention relates to a nuclear fuel body comprising tungsten network and a method for manufacturing the same, more particularly, a nuclear fuel body in which tungsten network is continuously formed over the entire or some parts of a sintered body and a method for manufacturing the same. The sintered body in the nuclear fuel body of the present invention contains tungsten network having excellent heat conductivity, leading to the enhancement of heat conductivity of the nuclear fuel sintered body itself with decreasing the temperature of the nuclear fuel, so that it can contribute to the improvement in safety and performance of nuclear fuel.
摘要:
A wire feeding unit includes a driving motor; a driving roller which rotates by a driving force of the driving motor; a plurality of driven rollers arranged such that outer circumferential surfaces thereof are positioned on a same line; a belt which interlocks the driving roller and the plurality of driven rollers and is brought into contact with a wire, which is drawn into a side of the driven rollers, on a side of the plurality of driven rollers; and a plurality of idlers which support the wire on a side in which the wire and the belt are in contact with each other and assist feeding of the wire along a feeding direction of the belt in a free-rotation state.
摘要:
The invention presented herein relates to a zirconium alloy with superior corrosion resistance and high strength for use in fuel rod claddings, spacer grids and structural components in reactor core of light water and heavy water nuclear power plant. The zirconium alloy of this invention with superior corrosion resistance and high strength comprises an alloy composition as follows: niobium in a range of 0.15 to 0.25 wt. %; tin in a range of 1.10 to 1.40 wt. %; iron in a range of 0.35 to 0.45; chromium in a range of 0.15 to 0.25; one element selected from the group consisting of molybdenum, copper and manganese in a range of 0.08 to 0.12 wt. %; oxygen in a range of 0.10 to 0.14 wt. %; and the balance being zirconium.
摘要:
The present invention relates to a zirconium alloy having excellent corrosion resistance and mechanical properties and a method for preparing a nuclear fuel cladding tube by zirconium alloy. More particulary, the present invention is directed to a zirconium alloy comprising Zr-aNb-bSn-cFe-dCr-eCu (a=0.05-0.4 wt %, b=0.3-0.7 wt %, c=0.1-0.4 wt %, d=0-0.2 wt % and e=0.01-0.2 wt %, provided that Nb+Sn=0.35-1.0 wt %), and to a method for preparing a zirconium alloy nuclear fuel cladding tube, comprising melting a metal mixture comprising of the zirconium and alloying elements to obtain ingot, forging the ingot at &bgr; phase range, &bgr;-quenching the forged ingot at 1015-1075° C., hot-working the quenched ingot at 600-650° C., cold-working the hot-worked ingot in three to five passes, with intermediate vacuum annealing and final vacuum annealing the worked ingot at 460-540° C., which can be applied to the core components in a light water and a heavy water atomic reactor type nuclear power plant.
摘要:
A lips-type multi-purposed spacer grid for supporting fuel rods within a nuclear fuel assembly is disclosed. In the spacer grid, the fuel rods are in contact with dimples and water strider-type springs in an equiangular surface contact manner. The spacer grid distributes load, applied to the springs, to the entire structure of its inner strips, thus reducing peak stress at the contact surfaces between the fuel rods and the springs and diminishing vibration of the fuel rods, and thereby reducing possible fretting wear of the fuel rods due to hydraulic vibration of the fuel rods. The spacer grid also enlarges the allowable elastic range of the springs, and allows the springs to soundly support the fuel rods by using residual spring force. The spacer grid has mixing blades capable of minimizing pressure loss and flow interference, so that the fuel rod cooling efficiency of the nuclear fuel assembly is improved.
摘要:
A spacer grid used for placing and supporting fuel rods in nuclear reactor fuel assemblies is disclosed. The spacer grid of this invention has a plurality of grid springs designed to have an optimal shape of their vertical support parts, thus reducing fretting wear of the fuel rods caused by contact of the fuel rods with the grid springs. The grid spring has a vertical support part and a fuel rod support part. The vertical support part includes upper and lower base parts extending downward and upward from the central portions of the top and bottom edges of an opening formed at the central portion of a unit strip, and two bridge parts branched from the upper base part and extending symmetrically downward until they are united at the lower base part. The fuel rod support part includes a conformal support part brought into surface contact with the external surface of a fuel rod. Two transverse connection parts extend outward from the opposite outside edges of the conformal support part while being specifically bent, and are integrated with the central portions of the inside edges of the two bridge parts into a single structure, thus connecting the fuel rod support part to the vertical support part.
摘要:
A grid with coolant deflecting channels for used in nuclear fuel assemblies is disclosed. In the grid, two sets of intersecting grid strips are arranged in sets at right angles to each other prior to being encircled by four perimeter strips, thus forming a plurality of four-walled cells individually placing and supporting an elongated fuel rod therein. Each of the grid strips is made up of two narrow sheets which are deformed at a plurality of regularly spaced portions to provide nozzle-type coolant deflecting channels. The channels individually have an upright Y-shaped or reversed Y-shaped configuration capable of so deflecting coolant as to mix low temperature coolant with high temperature coolant. The channels thus form a uniform temperature distribution within a fuel assembly. The channels are so inclined with respect to the axes of the fuel rods as to form wide and linear positioning springs at middle portions thereof. The middle portions of the channels thus individually have a dual function of a deflecting channel for coolant and a positioning spring for the fuel rods.
摘要:
The present invention is directed to an advanced zirconium alloy having superior corrosion resistance and high strength suitable for fuel rod cladding, spacer grids and other structural components in a reactor core of nuclear power plants.
摘要:
The invention presented herein relates to a niobium-containing zirconium alloy for use in nuclear fuel cladding. The Zr alloy of this invention with superior corrosion resistance is characterized as comprising an alloy composition as follows: 1) niobium (Nb), in a range of 0.8 to 1.2 wt. %; one or more elements selected from the group consisting of iron (Fe), molybdenum (Mo), copper (Cu) and manganese (Mn), in a range of 0.1 to 0.3 wt. %, respectively; oxygen (O), in a range of 600 to 1400 ppm; silicon (Si), in a range of 80 to 120 ppm; and the balance being of Zr, 2) Nb, in a range of 1.3 to 1.8 wt. %; tin (Sn), in a range of 0.2 to 0.5 wt. %; one element selected from the group consisting of Fe, Mo, Cu and Mn, in a range of 0.1 to 0.3 wt. %; O, in a range of 600 to 1400 ppm; Si, in a range of 80 to 120 ppm; and the balance being of Zr, 3) Nb, in a range of 1.3 to 1.8 wt. %; Sn, in a range of 0.2 to 0.5 wt. %; Fe, in a range of 0.1 to 0.3 wt. %; one element selected from the group consisting of chromium (Cr), Mo, Cu and Mn, in a range of 0.1 to 0.3 wt. %; O, in a range of 600 to 1400 ppm; Si, in a range of 80 to 120 ppm; and the balance being of Zr, and 4) Nb, in a range of 0.3 to 1.2 wt. %; Sn, in a range of 0.4 to 1.2 wt. %; Fe, in a range of 0.1 to 0.5 wt. %; one element selected from the group consisting of Mo, Cu and Mn, in a range of 0.1 to 0.3 wt. %; O, in a range of 600 to 1400 ppm; Si, in a range of 80 to 120 ppm; and the balance being of Zr.