THE EMANATION OF RADON 220 FROM SINTERED UO$sub 2$ POWDERS AND PLATES
The emanation of thoron (Rn/sup 220/) from sintered UO/sub 2/ powders and plates was measured as a function of temperature. The uranium oxide samples were indexed with radiothorium by coprecipitation and coevaporation techniques. The emanation measurements were performed in a flow system, using an alpha scintillation detector and a helium-hydrogen carrier gas mixture. Both the radiothorium concentration (5 to 100 mu C/g UO/sub 2/) and the uranium oxide density (71 to 99 percent TD) were varied. The surface areas and densities of the UO/sub 2/ plates were measured by krypton gas adsorption and liquid immersion techniques, respectively. Assuming a diffusion mechanism, diffusion coefficients for thoron in sintered UO/sub 2/ were calculated as a function of temperature. The data were represented by an equation of the form, D = D/sub O/ exp (-Q/RT). An apparent increase in both activation energy (Q) and D/sub O/ with density was observed for the 1100 to 1450 deg C temperature range. For some samples the thoron emanating power could be measured at temperatures as low as 400 deg C. Log D versus 1/T plots from 400 to 1450 deg C gave intersecttng straight lines with different activation energies. One intersection occurred near the Tammann temperature. The emanation of Rn/sup 220/ from UO/sub 2/ apparently involves several types of diffusion processes. (auth)
- Research Organization:
- Westinghouse Electric Corp. Bettis Atomic Power Lab., Pittsburgh
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AT(11-1)-GEN-14
- NSA Number:
- NSA-18-004183
- OSTI ID:
- 4126097
- Report Number(s):
- WAPD-276
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ADSORPTION
DENSITY
DIFFUSION
ENERGY
EQUATIONS
EVAPORATION
HELIUM
HIGH TEMPERATURE
HYDROGEN
KRYPTON
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
NUMERICALS
PLATES
POWDERS
QUANTITY RATIO
RADON
RADON 220
SCINTILLATION COUNTERS
SINTERED MATERIALS
SINTERING
SURFACES
TEMPERATURE
THORIUM
TRACER TECHNIQUES
URANIUM DIOXIDE