FIELD: alloy preparation technology. SUBSTANCE: zirconium-based alloy for manufacturing parts used in nuclear reactor, in addition to zirconium (at least 96 wt %) and sulfur (8 to 100 ppm, preferably 8 to 30 ppm), contains, wt %: (tin 1.2-1.7, iron 0.18-0.25, and chromium 0.07-0.13) or (tin 1.2-1.7, iron 0.07-0.2, nickel 0.05-0.15, and chromium 0.05-0.15), or (niobium 0.7-1.3 and oxygen 0.09-0.16 ppm), or (tin 0.3-1.4, iron 0.4-1, vanadium or chromium 0.2-0.7, and oxygen 500-1800 ppm), or (niobium 0.7-1.3, tin 0.9-1.5, iron 0.1-0.6, chromium 0.01- 0.2, and oxygen 500-1800 ppm), or (tin about 0.7-1.25, iron 0.1-0.3, chromium 0.05-0.2, niobium 0.1-0.3, nickel 0.01-0.02, and oxygen 500-1800 ppm), or niobium 0.1-0.3, or (tin 0.3-0.7, iron 0.3-0.7, chromium 0.1-0.4, nickel 0.01- 0.04, silicon 70-120 ppm, and oxygen 500-1800 ppm). Proposed alloy is used to manufacture sealing tube for fuel slug, structural element of fuel assembly, in particular guiding tube, and casing for disposing fuel slug's bundle. Alloy is prepared by adding, to initial alloy composition, sulfur-containing zirconium dioxide and, if necessary, sulfur-free zirconium dioxide. Alloy preparation method may also involve adding, to initial alloy composition, at least one of following compounds: tin sulfide and iron sulfide. EFFECT: achieved workability of alloy by known industrial techniques and improved its resistance flowability and corrosion. 17 cl, 4 tbl
