POWER REACTOR PROGRAM. Progress Report to Savannah River Operations Office, United States Atomic Energy Commission for the Period January 1, 1961 through January 31, 1961

Technical Report · Fri Mar 24 04:00:00 EST 1961

OSTI ID:4028775

Isserow, S; White, A M; Jordan, E F; Richmond, W J; Larson, W L; Smoot, P R; Green, H M; Gilman, A R; Tuffin, W B

An analysis was made of the cladding thickness of various tubes. Experiments showed that small changes in the cooling rate following beta treatment of tubes influence the final grain size of the cores. A summary of cladding thickness data obtained by autoradiography and eddy current for the inner tubes of the demonstration set shows that the cladding is everywhere at least 20-mils thick. As the result of brazing trials on dingot specimens it appears that diretional solidification will be necessary to eliminate voids. Samples of a U-0.3 wt.% Al-0.5 wt.% Si alloy solotionized before extrusion were examined metallographically in different conditions. By oil quenching after gamma treating, precipitation of the dispersed phase was prevented; subsequent aging caused a fine precipitated phase to appear. Bond integrity was good for samples in the as-extruded and beta treated conditions and poor for all gamma treated specimens whether air cooled or oil quenched. Cracks are found in the U- 0.3 wt.% Cr-0.3 wt.% Mo alloy as cast and after subsequent operations. The grain size of a U-0.4 wt.% Al (nominal U-0.6 wt.% Al) casting is too coarse to give a satisfactory core-cladding interface and triple beta treatment did not seem to reduce grain size sufficiently. In the study of the penetration of magnesium and of Mg-0.4 wt.% Si alloy in Zircaloy, sandwich-type couples give fairly uniform and reproducible values at 500 deg C if the components of the couple are etched before assembly. Penetration rates are about the same for pure magnesium and for the alloy at 500 deg C. Tensile specimens through the diffusion zone of couples treated at 500 deg C broke on the Zircaloy side of the original interface at values of 5,000 to 5,500 psi (as compared to 12,000 psi for magnesium). In bend tests on Zircaloy tubes coated by dipping in molten magnesium, cracks originated in the magnesium, progressed radially to the bond zone and then propagated circumferentially. Uranium cores of coextruded Zircaloy-clad tubes were melted in situ. When heating was controlled at the melting point of uranium or 15 deg C above, the cladding thickess decreased no more than 0.4 mils, and the formation of an interfacial zone appeared to degrade the ductility of the bond. Diameters increased as the result of melting and there were shrinkage voids at the zones that were melted last. Bowing occurs but there is evidence that it can be controlled by proper support. (auth)

• Research Organization: Nuclear Metals, Inc., Concord, Mass.
• NSA Number: NSA-15-016012
• OSTI ID: 4028775
• Report Number(s): NMI-7236
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM ALLOYS
BONDING
CHROMIUM ALLOYS
COATING
CONTROL
CRACKS
DEFORMATION
DIFFUSION
DUCTILITY
EDDY CURRENTS
ETCHING
EXTRUSION
FUEL CANS
GRAIN SIZE
HEAT TREATMENTS
MAGNESIUM
MAGNESIUM ALLOYS
MATERIALS TESTING
MELTING
MELTING POINTS
METALLOGRAPHY
METALS, CERAMICS, AND OTHER MATERIALS
PHASE DIAGRAMS
PRECIPITATION
QUANTITATIVE ANALYSIS
RADIOAUTOGRAPHY
SILICIDES
TEMPERATURE
TENSILE PROPERTIES
THICKNESS
TUBES
URANIUM
URANIUM ALLOYS
ZIRCALOY