Method for manufacturing a tube and a sheet of niobium-containing zirconium alloy for a high burn-up nuclear fuel

摘要

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 beta phase range; beta-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 beta-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 (SIGMAA) is limited to 1.0x10-18 hr or lower, thereby yielding a tube and a sheet of Nb-containing zirconium alloys with excellent corrosion resistance and mechanical properties, capable of stably maintaining nuclear fuel in operation conditions of high temperature/high pressure of high burn-up reactor cores. Such Nb-added zirconium alloys are useful as nuclear fuel cladding tubes, grids and structures of the cores in the light water reactors and heavy water reactors.