FUELS TESTING AND ANALYSIS

Technical Report · Wed Oct 30 23:00:00 EST 1963

OSTI ID:4652222

The general appearance of eight carefully inspected irradiated PRTR fuel elements was good and no serious cladding defects were observed. Local high fuel temperatures in a swaged, incrementally loaded, UO/sub 2/-- PuO/sub 2/ PRTR fuel rod were sufficient to cause center void formation and columnar grain growth. Only minor fuel washout and contanrination release occurred following the failure of a vibrationally compacted, UO/sub 2/-- PuO/sub 2/ fuel element in the PRTR. The cause of the failure was not determined. Preliminary gas release data from PRTR tubular fuel elenrent (No. 1501) indicated that less than 10% of the fission gases and less than 50% of the sorbed gases were released during irradiation. Process tube wear was reduced by increasing the contact surface area of irradiated PRTR fuel elements. Irradiation tests of prototypic, vibrationally compacted, EBWR, UO/sub 2/-- PuO/sub 2/ fuel rods were initiated. Migration of fission products and/or PuO/sub 2/ occurred during irradiation at high fuel temperatures in both MgO--PuO/sub 2/ and ZrO/sub 2/-- PuO/sub 2/ fuel pellets. Autoradiographs showing marked plutonium and/or fission product migration aided microsampling of irradiated UO/sub 2/-- PuO/sub 2/ pellets. A six-fold difference in specific gamma activity was found in samples removed from the same pellet. Capsules containing pneumatically impacted UO/sub 2/-- PuO/sub 2/ (0.505 inch diameter fuel) were irradiated at a surface heat flux of approximately 900,000 Btu/(hr)(sq ft). The thermal conductivity of large grain (single and bicrystal) UO/sub 2/ was apparently greater than that of small grain UO/sub 2/ during irradiation. UO/sub 2/-W cermets were chemically and dimensionally stable during irradiation for 2 hours with a surface temperature greater than 2100 deg C. The gross reactivity of an Al- Pu fueled test capsule made of high exposure (27.17% Pu/sup 210/) plutonium was 38% greater than that of a similar capsule incorporating low exposure (6.25% Pu/sup 210/) plutonium after irradiation to 1.2 x 10/sup 20/ fissions/cc (92% burnup of original fissionable atoms). ThO/sub 2/-PuO/sub 2/ irradiation test pellets (95 to 96% TD) containing 2 to 5 wt% PuO/sub 2/ were made by dry pressing calcined powder mixtures and sintering in hydrogen at 1600 deg C for 6 hours. No bonding of fuel particles was observed in cold-swaged UO/sub 2/ heated out-of-reactor for more than 1000 hours at 550 deg C corfirming the hypothesis that sintering observed in PRTR fuel rods is an irradiation effect. Flux monitor measurements showed that four capsules previously described generated rod powers between 18.3 and 23.7 kw/ft. Problems associated with postirradiation examination of low exposure plutonium fuels are discussed. (auth)

• Research Organization: General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
• NSA Number: NSA-17-036198
• OSTI ID: 4652222
• Report Number(s): HW-76301(Paper 3)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALUMINUM ALLOYS
BEAMS
BONDING
BURNUP
COATING
COLD WORKING
COMPACTING
DEFECTS
DIFFUSION
EBWR
EXPANSION
FAILURES
FISSION PRODUCTS
FUEL CANS
FUEL ELEMENTS
FUELS
GAMMA RADIATION
GASES
GRAIN SIZE
HEAT TRANSFER
HIGH TEMPERATURE
HYDROGEN
IRRADIATION
MAGNESIUM OXIDES
MATERIALS TESTING
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
PLUTONIUM ALLOYS
PLUTONIUM OXIDES
POWDERS
PRTR
RADIATION EFFECTS
RADIOAUTOGRAPHY
REACTIVITY
RODS
SINTERED MATERIALS
SINTERING
STABILITY
SURFACES
THERMAL CONDUCTIVITY
TRACER TECHNIQUES
TUBES
URANIUM DIOXIDE
VOIDS
WASHOUT
WEAR
ZIRCONIUM OXIDES