POWER REACTOR PROGRAM. Progress Report to Savannah River Operations Office, United States Atomic Energy Commission for the Period March 1, 1962-March 31, 1962

Technical Report · Fri Jun 01 04:00:00 EDT 1962

OSTI ID:4785045

Isserow, S; Anderson, R W; Bremer, A B; Davies, D M; Richmond, W J; Larson, W L

Evaluation was completed on the prototype for the enriched U inner tubes. The uniformity of the outside cladding was determined, and the results support the decision to use, as cladding stock for the enriched tubes, only Zircaloy initially forged at temperatures below 1650 deg F. Three outer tubes were coextruded with cores prepared by a relatively simple and economical process requiring only a single alpha extrusion. The smoothness of the corecladding interfaces showed that this process is adequate for refinement of the U grains. The program to produce fuel tubes containing cores of various U alloys for irradiation in the HWCTR was resumed. Components for the next two extnusion billets, containing U-1 wt.% Si and U-1.5 wt.% Mo cores, are being prepared. The equipment for sealing the ends of HWCTR tubes by brazing was modified to accept tube sections 6 ft long. Several brazed end closures were made with the modified equipment. As part of a continuing effort to develop a metallic fuel with emproved irradiation behavior, several alloy systems were studied metallographically and by hot hardness testing. A sub-micron precipitate can be produced by proper heat treatment in U-0.08 wt.% Si, U-0.3 wt.% Al-0.5 wt.% Si system and in the recently developed U-0.3 wt.% Al-0.18 wt.% Si system. The data suggest that alpha U has finer grains if its transformation from beta occurs at lower temperatures than usual. Hot hardness studies of as-cast U alloys containing 0.15, 0.4, 1.0 and 1.5 wt.% Mo showed that all of the alloys are harder than unalloyed U. The 0.4 wt.% Mo alloy is consistently harder than the other compositions. Above 500 deg C, the hardnesses of the alloys tend to fall to the level of the 0.15 wt.% Mo solid solution alloy. The hardness transition temperature of all the alloys is increased to the 450 to 500 deg C range. Tests on wrought U1.5 wt.% Mo heat-treated to five different conditions show that a wide variety of microstructures and hardness properties can be developed. These wrought materials did not exhibit the higher hardness transition temperature observed for the cast alloys. (auth)

• Research Organization: Nuclear Metals, Inc., Concord, Mass.
• NSA Number: NSA-16-030085
• OSTI ID: 4785045
• Report Number(s): NMI-7249
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM ALLOYS
BRAZING
CLOSURES
DISTRIBUTION
ECONOMICS
EXTRUSION
FABRICATION
FUEL CANS
FUEL ELEMENTS
GRAIN SIZE
HARDNESS
HEAT TREATMENTS
HIGH TEMPERATURE
HWCTR
IRRADIATION
METALLOGRAPHY
MOLYBDENUM ALLOYS
POWER PLANTS
PRECIPITATION
QUANTITY RATIO
REACTOR TECHNOLOGY
REACTORS
SEALS
SILICIDES
TESTING
TUBES
URANIUM ALLOYS
VARIATIONS
ZIRCALOY