THE FORMATION AND STATISTICAL EVALUATION OF "DIFFUSION BONDED" BRAZED JOINTS IN YANKEE FUEL SUBASSEMBLIES

Technical Report · Sun Nov 01 04:00:00 EST 1959

OSTI ID:4146305

King, P P

The factorr controlling the formation and growth of "diffusion bonded" joints in fuel tube-to-ferrule joints were investigated. Joint strengths in fuel element subassemblies with varying brazing alloy-s and brazing cycles were compared and evaluated by statistical analyses of joint fracture loads from prototype subassemblies. Joint clearance was found to be the most critical factor controlling the formation and growth of "diffusion bonded" areas in fuel tube-to-ferrule joints. Clearances below 0.0025 inches were found necessary for "diffusion bonding." Joint strengths were found to increase with time at temperature if the joint clearances were within the range specified. Preplacement of the brazing alloy by plating one of the components eliminated voids and porosity at the joint centers which are caused by lack of braze flow into joint clearances below 0.0005 inches. Joint strength data taken from single joint specimens did not represent the joint strength level in full sized subassemblies because variations ofjoint clearances in muitiple tube subassemblies lowered the average joint strength appreciably. Statistical evaluation of joints taken from full sized subassemblies was found to give the most accurate representation of fuel element strength and quaiity. (auth)

• Research Organization: Westinghouse Electric Corp. Atomic Power Dept., Pittsburgh
• NSA Number: NSA-14-012361
• OSTI ID: 4146305
• Report Number(s): YAEC-160
• Country of Publication: United States
• Language: English

Related Subjects

ALLOYS
BONDING
BRAZING
DIFFUSION
FUEL ELEMENTS
JOINTS
MECHANICS
POROSITY
POWER PLANTS
REACTOR TECHNOLOGY
STATISTICS
TEMPERATURE
TUBES
YAEC
YANKEE