Abstract: 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.

Abstract: A PLL circuit may include a memory for storing a control voltage and a processor for loading a control voltage, which corresponds to a changed channel, from the memory when a system channel is changed, and providing the control voltage to a Voltage Control Oscillator (VCO). Whenever a system changes a channel, a control voltage of a pertinent channel frequency that has been stored in the memory may be used as an initial value of a control voltage provided to the VCO 50 so that a time (i.e., a lock time) to perform a phase lock looping may be remarkably reduced. This may improve a processing speed of various communication equipments and their performance.

Abstract: The present invention relates to a method for manufacturing zirconium-based alloys containing niobium with superior corrosion resistance for use in nuclear fuel rod claddings. The method of this invention comprises melting of the alloy, &bgr;-forging, &bgr;-quenching, hot-working, vacuum annealing, cold-working, intermediate annealing and final annealing, whereby the niobium concentration in the &agr;-Zr matrix decreases from the supersaturation state to the equilibrium state to improve the corrosion resistance of the alloy. Such zirconium-based alloys containing niobium are usefully applied to nuclear fuel rod cladding of the cores in light water reactors and heavy water reactors.

Abstract: 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.

Abstract: Disclosed is a method for manufacturing a tube and a sheet of niobium-containing zirconium alloys for the high burn-up nuclear fuel. The method comprises melting Nb-added zirconium alloy to ingot; forging the ingot at &bgr; phase range; &bgr;-quenching the forged ingot after solution heat-treatment 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 cold-worked ingot at 440-600° C., wherein temperatures of intermediate vacuum annealing and final vacuum annealing after &bgr;-quenching are changed so as to attain the condition under which precipitates in the alloy matrix are limited to an average diameter of 80 nm or smaller and the accumulated annealing parameter (&Sgr; A) is limited to 1.0×10−18 hr or lower.

Abstract: Disclosed is a method for manufacturing a tube and a sheet of niobium-containing zirconium alloys for the high burn-up nuclear fuel. The method comprises melting Nb-added zirconium alloy to ingot; forging the ingot at &bgr; phase range; &bgr;-quenching the forged ingot after solution heat-treatment 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 cold-worked ingot at 440-600° C., wherein temperatures of intermediate vacuum annealing and final vacuum annealing after &bgr;-quenching are changed so as to attain the condition under which precipitates in the alloy matrix are limited to an average diameter of 80 nm or smaller and the accumulated annealing parameter (&Sgr;A) is limited to 1.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 as used 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(Nb), in a range of 0.05 to 0.3 wt. %;tin(Sn), in a range of 0.8 to 1.6 wt. %;iron(Fe), in a range of 0.2 to 0.4 wt. %;a selected one from the group consisted of vanadium(V), tellurium(Te), antimony(Sb), molybdenum(Mo), tantalum(Ta), and copper(Cu), in a range of 0.05 to 0.20 wt. %;oxygen(O), in a range of 600 to 1400 ppm; andthe balance being zirconium(Zr).