ZIRCONIUM BASE ALLOY AND METHOD FOR MANUFACTURING NUCLEAR-REACTOR FUEL-ASSEMBLY ELEMENT FROM THIS ALLOY Russian patent published in 2005 - IPC

FIELD: nuclear engineering; pressurized water reactors.

SUBSTANCE: zirconium base alloy used for producing fuel-assembly elements has in its composition 0.02 - 1 mass percent of iron, 0.08 - 2.3 mass percent of niobium, less than 2000 parts by million of tin, less than 2000 parts by million of oxygen, less than 100 parts by million of carbon, 5 - 35 parts by million of sulfur, and less than 0.25 mass percent of chromium and/or vanadium as a whole, as well as inevitable impurities. Ratio R of niobium content minus 0.5 mass percent and iron content with chromium and/or vanadium added, if necessary, is below 3. Sealing tube and rolled sheets for reactor fuel rods are made of this alloy in re-crystallized state. Method for producing tubes designed to form entire fuel-rod can or its external part, or to produce fuel-assembly guide tube involves manufacture of zirconium base alloy bar. This bar is heated to 1000 - 1200 °C followed by abrupt cooling down with water, and workpiece obtained is drawn upon heating to 600 - 800 °C. Then workpiece is subjected to cold rolling and intermediate heat treatment at 560 - 620 °C, to final heat treatment at 560 - 620 °C. All these heat treatment procedures are conducted in inert atmosphere or in vacuum.

EFFECT: facilitated manufacture, enhanced quality of fuel elements.

7 cl, 3 dwg