POST IRRADIATION EXAMINATION OF SEVEN ELEMENT ZIRCALOY-SHEATHED UO$sub 2$ FUEL BUNDLES IRRADIATED IN PRESSURIZED WATER TEST CR-V-e

Technical Report · Tue Aug 01 04:00:00 EDT 1961

OSTI ID:4826988

Bain, A S; MacDonald, R D; Robertson, J A.L.

Zircaloy-2 sheathed UO/sub 2/ pellets, enriched to 7.95 wt% U/sup 235/ in total U, and assembled into seven-rod clusters, were irradiated for 145 days in a pressurized water loop. The most highly rated element operated at 505 W/cm length, and achieved a burn-up ln excess of 7,500 MWd/ ton of U. The outer elements of each bundle had bowed outward by a maximum of 0.05 in., but there was no measurable change in diameter of the individual elements. The temperatures at the center of the fuel were sufficiently high to cause appreciable grain growth in the UO/sub 2/. Severe distortion of the neutron flux distribution by the highly enriched fuel caused the grain growth region to be displaced toward the outside of the bundle by about 1/4 of the element's radius. The bowing of the elements was attributed to the thermal asymmetry. The values of the fuel burn-up deduced from loop calorimetry were in agreement, within experimental error, with those obtained by chemical analysis; the heat rating required to produce grain growth was compatible with previous experience. This irradiation confirmed the feasibility of using highly rated UO/sub 2/ in Zircaloy sheathing for fuel assemblies in water-cooled reactors. (auth)

• Research Organization: Atomic Energy of Canada Ltd., Chalk River, Ont.
• NSA Number: NSA-16-003817
• OSTI ID: 4826988
• Report Number(s): CRFD-1011; EXP-NRX-1104; AECl-
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BURNUP
CALORIMETERS
CANNING
CONFIGURATION
COOLANT LOOPS
DEFORMATION
DISTRIBUTION
EFFICIENCY
ERRORS
EXPANSION
FUEL ELEMENTS
GRAIN SIZE
HIGH TEMPERATURE
IRRADIATION
MATERIALS TESTING
MEASURED VALUES
MOCKUP
NEUTRON FLUX
PELLETS
POWER PLANTS
PRESSURE
QUALITATIVE ANALYSIS
RADIATION DOSES
RADIATION EFFECTS
REACTOR TECHNOLOGY
REMOTE HANDLING
RODS
THERMAL STRESSES
THICKNESS
URANIUM
URANIUM 235
URANIUM DIOXIDE
VARIATIONS
WATER COOLANT
ZIRCALOY
ZONES