FUEL ELEMENTS, METHOD OF MANUFACTURE OF FUEL ELEMENTS AND DEVICE FOR ITS EMBODIMENT Russian patent published in 1997 - IPC

FIELD: nuclear technology; designs of fuel elements and technology of their manufacture. SUBSTANCE: fuel element has shell and plug welded into shell with some deepening. Provided in welding zone of plug is region with changed structure of metal to the depth of plug sinking equalling (2-5)δ and with thickness on the side of internal surface of shell of not in excess of 0.9d, where d is thickness of shell walls. The offered method includes manufacture of plug with outer diameter exceeding the shell inner diameter by (0.2-1.4) d, where d is thickness of shell walls, fixing of shell in current lead with deepening, compression of shell with plug and heating of welded components with electric current. Current in this event, is distributed over current lead and shell, so that current flowing over the section of shell with length of (2-5)d from its end is equal to 0.3-0.9 of welding current to provide for heat removal from external surface of shell. The device for embodiment of the offered method has circular current lead, whose one part comes in contact with end face region and is assembled of a set of electrically insulated plates interconnected with one another by electric shunt. Each plate has thickness of (0.2-2)d, where d is shell thickness. Assembled part of current lead along axis of its opening is made with length of (2.5-6)d. EFFECT: higher efficiency. 5 cl, 5 dwg