Zirconium alloy composition for nuclear fuel, and preparation method therefor

The purpose of the present invention is to provide a zirconium alloy composition and a preparation method therefor, the zirconium alloy composition having excellent mechanical properties and corrosion resistance and capable of being used within a nuclear power plant reactor which gradually becomes harsher while aiming not only for high-temperature, high-pressure, and water-chemistry environments within the reactor, but also long-period, high burn-up, and load-following operations. The zirconium alloy composition for nuclear fuel, according to the present invention for achieving the purpose, comprises: 0.9-1.7 % by weight of niobium (Nb); 0.01-0.3 % by weight of stannum (Sn); 0.1-0.7 % by weight of chromium (Cr); 600-1,400 ppm of oxygen (O); and zirconium (Zr) as the remainder. Further, the method for preparing a zirconium alloy composition for nuclear fuel, according to the present invention for achieving the purpose, comprises: a step of producing an ingot by melting elements of the alloy composition (SI); a step of subjecting the ingot produced in step SI to heat treatment at a phase region temperature and rapidly cooling the ingot to room temperature (SII); a step of subjecting the ingot cooled in step SII to preheating and hot-rolling (SIII); a step of subjecting the rolled material, which has been hot-rolled in step SIII, to primary intermediate heat treatment and then to primary cold-rolling (SIV); a step of subjecting the rolled material, which has been rolled in step SIV, to secondary intermediate heat treatment and then to secondary cold-rolling (SV); a step of subjecting the rolled material, which has been rolled in step SV, to tertiary intermediate heat treatment and then to tertiary cold-rolling (SVI); and a step of subjecting the rolled material, which has been rolled in step SVI, to final heat treatment (SVII).