JOINING FUEL RODS INTO SUBASSEMBLIES FOR YAEC FUEL ELEMENTS

Technical Report · Mon Dec 01 04:00:00 EST 1958

OSTI ID:4261255

King, P P

High temperature brazing, tungsten inert gas weldings and resistance spot welding were investigated and evaluated for possible use in joining fuel rods into subassemblies for YAEC fuel elements. Tungsten inert gas welding of straps to fuel rods was accomplished but the weld penetration into the fuel rods was somewhat difficult to control. Resistance spot welding was completely unsatisfactory in that the high welding current necessary for fusion overheated and melted the fuel rod cladding when pellet filled fuel rods were used. Brazing appeared to be the most promising fabrication technique so factors such as joint corrosion resistances joint strengths base metal reactions and brazing cycles were investigated. Brazing of 95 inch long fuel element subassemblies was found to be feasible using nickelphosphorous and nickel-chromium-phosphorous brazing alloys. Brazing temperatures between 1800 and 1900 F were found to be the most suitable for controlling base metal grain growth and dimensional tolerances. One to three hours at temperature gave adequate joint strength to full-sized subassemblies. Fuel tube-to-ferrule fitup was found to be the most critical factor in influencing joint strength. Fixture design was found to be critical in maintaining fuel bundle dimensions straightness and ferrule-to-fuel rod fitup. (auth)

• Research Organization: Westinghouse Electric Corp. Atomic Power Dept., Pittsburgh
• NSA Number: NSA-13-014096
• OSTI ID: 4261255
• Report Number(s): YAEC-108
• Country of Publication: United States
• Language: English

Related Subjects

BRAZING
CHROMIUM ALLOYS
CONFIGURATION
CORROSION
FAILURES
FUEL CANS
FUEL ELEMENTS
GRAIN SIZE
HIGH TEMPERATURE
INERT GASES
IRON
JOINTS
MECHANICAL PROPERTIES
MELTING
METALS
NICKEL ALLOYS
PELLETS
PHOSPHIDES
PHOSPHORUS COMPOUNDS
REACTORS
RODS
SHEETS
TUNGSTEN
USES
VOLUME
WELDING
WELDS
YAEC