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

FIELD: nuclear engineering; pressurized water reactors.

SUBSTANCE: zirconium base alloy used for manufacturing fuel-assembly elements has in its composition 0.02 - 1 mass percent of iron, 0.8 - 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 0.01 - 0.25 mass percent of chromium and/or vanadium as a whole, as well as inevitable impurities. Ratio R between content of niobium minus 0.5 mass percent and that of iron not necessarily added by chromium and/or vanadium is higher than 2.5. Sealing tube and rolled sheets for reactor fuel rods are manufactured from this alloy in re-crystallized state. Method for manufacturing tubes designed to form entire can of fuel rod 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 its abrupt cooling down with water whereupon it is heated to 600 800 °C, and workpiece obtained in the process is extruded. This workpiece is subjected to cold rolling and in the process it undergoes heat treatment at 560 - 620 °C and then final heat treatment at 560 - 620 °C.

EFFECT: facilitated manufacture, enhanced quality of fuel elements.

11 cl, 3 dwg