INVESTIGATION OF ThO$sub 2$-UO$sub 2$ AS A NUCLEAR FUEL

Technical Report · Mon Jul 01 04:00:00 EDT 1963

OSTI ID:4150132

Rao, S V.K.

To evaluate the potential of ThO/sub 2/-- UO/sub 2/ as a nuclear fuel, specimens with UO/sub 2/ contents from 2.7 to 19 wt% were irradiated in the Hydraulic Rabbit of the NRX Reactor. In these three-minute irradiations, the power output to produce central melting in the ThO/sub 2/-- UO/sub 2/ sinters decreased as the UO/sub 2/ content increased from 5.4 to 19 wt%. The decrease was partly due te an associated increase in porosity with increasing UO/sub 2/ content in these particular specimens, but there was also a decrease in the thermal conductivity of the solid itself. The diametral and longitudinal expansions of the sheath were very similar to those previously observed with pure UO/sub 2/. No difference in expansion behavior between various compositions was observed, when allowance was made for the difference in thermal conductivity already deduced. Air-fired sinters exhibited more grain growth than comparable hydrogenfired ones, but the sheath expansions were not significantly different. It appears that hydrogen-fired sinters with a UO/sub 2/ content of 5 to 10 wt% UO/ sub 2/ behave in essentially the same manner as those of pure UO/sub 2/. Increasing the UO/sub 2/ content up to 19% results in a poorer performance, while extrapolation suggests that the performance would improve with the UO/sub 2/ content decreasing from 5 wt%. (auth)

• Research Organization: Atomic Energy of Canada Ltd., Chalk River, Ont.
• NSA Number: NSA-18-002217
• OSTI ID: 4150132
• Report Number(s): CRFD-1154; AECL-1785
• Country of Publication: Canada
• Language: English

Related Subjects

AIR
EXPANSION
FUELS
GRAIN SIZE
HYDROGEN
IRRADIATION
MELTING
METALS, CERAMICS, AND OTHER MATERIALS
POROSITY
POWER
QUANTITY RATIO
SAMPLING
SINTERING
THERMAL CONDUCTIVITY
THORIUM OXIDES
URANIUM DIOXIDE