END SEAL DEFECTS IN COEXTRUDED REACTOR FUEL ELEMENTS (thesis)

Technical Report · Mon Jul 01 04:00:00 EDT 1957

OSTI ID:4232957

Lakey, K G; Risser, J B

The coextrusion process for the fabrication of clad reactor fuel elements is investigated to determine methods of optimizing the typical extrusion defect'' between the core and end seal materials. The influence of cone angle, conical preshaping, and relative material stiffness on the extrusion defect'' is studied under normal production conditions with copper-base alloys. The feasibility of the double extrusion technique with its considerable advantages over conventional methods is demonstrated and shown to be a valuable extension of the coextrusion process. Several undesirable side effects of coextrusion are studied and their major causes isolated. Shift is shown to result primarily from the effects of uneven lubrication of the extrusion tools. The whiskering phenomenon is studied under various conditions; the conclusion is that the difference in flow velocity of the hard and soft materials in the billet is responsible for their formation. Whiskering is shown to be controllable to a degree by billet geometry. (auth)

• Research Organization: Massachusetts Inst. of Tech., Cambridge
• NSA Number: NSA-13-019240
• OSTI ID: 4232957
• Report Number(s): NP-7767
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

DEFECTS
EXTRUSION
FUEL CANS
FUEL ELEMENTS
LUBRICATION
METALLURGY AND CERAMICS
SEALS
TOOLS
VELOCITY