METHOD FOR MANUFACTURING EXPANDING CHUCKS FOR RESISTANCE BUTT WELDING MACHINE Russian patent published in 2005 - IPC

FIELD: nuclear industry.

SUBSTANCE: proposed method is used for manufacturing fuel elements of type VVER-1000 and VVER-440 reactors when sealing them in resistance butt welding machine using expanding chuck. Novelty is that spent chucks cleaned from uranium dioxide are used as charge to be melted for producing new ones of sufficient strength and flexibility. Spent chucks are melted at 1300 - 1350°C for 20 - 25 min., melt is degassed at pressure of 4.5 x 10^-3 of mercury; when cleaning molten bronze from nonmetallic admixtures, the latter are upset on cooled crucible walls in the course of short-time disconnection and connection of inductor load; ingots obtained are hardened in water at 780 ±10°C and annealed at 320 - 340 °C for 3 - 3.5 h to make them flexible; then expanding chucks are manufactured by mechanical method.

EFFECT: provision for using spent chucks to produce new ones.

2 cl, 2 dwg