MEASUREMENT OF THE THERMAL CONDUCTIVITY OF LIQUID UO-2
The thermal conductivity of molten UO-2 was measured by a quasi-stationary method on a partially molten self-contained sample. A horizontal disc of UO-2 (6 mm in diameter, 1.2-3 mm thick) was heated in argon at 4 bar by means of two CW CO-2 laser beams. The high rate of evaporation of UO-2, even in argon at 4 bar, requires that the measurement be completed in a few seconds at higher temperature. The radial temperature profiles at the top and bottom surfaces were recorded by mechanically scanning the images of these surfaces transmitted through fibre optic image guides. The thermal conductivity of liquid UO-2 can be deduced from the known thermal conductivity of solid UO-2, from the measured radial temperature profiles, with some assumptions on the heat loss at the surfaces, and from the depth of penetration of the melting front. The data were evaluated by a two- dimensional finite element program. The results obtained so far do not confirm earlier findings by Kim et al, but rather indicate a thermal conductivity of the liquid of 2.2+-1.0W m**-1K**-1, which is 65 +- 15 % of the extrapolated value for the solid at the melting point.
Bibliographic Reference: HIGH TEMPERATURES-HIGH PRESSURES, VOL. 15 (1983), PP. 419-431
Record Number: 1989122043000 / Last updated on: 1987-01-01
Available languages: en