Some results uranium dioxide powder structure investigation

Mathematical and computational models for simulating transient nuclear criticality excursions within wetted fissile powder systems

“…The simulated speed of penetration satisfies experimental results when the mean powder particle size is between 9 µm and 10 µm. These mean powder particle sizes are similar to the range of UO 2 powder particle sizes observed in the cited literature [19,78,79].…”

“…Experimental work by Andreev et al [78], and Clayton and Aronson [79], indicate that lognormal powder particle size distributions are commonly found for UO 2 powders manufactured using various techniques. This corresponds well with many other powder systems whose mean powder particle size are distributed log-normally [67].…”

“…A comprehensive comparison regarding the various empirical and semi-empirical measures of saturated permeability carried out by Odong [77], indicated that the Koseny-Carman formula produced reliable results for particles sizes up to 300 µm. The anticipated particle size range for UO 2 powder produced using various manufacturing methods is from 1 µm to 100 µm distributed log-normally [78,79]. Therefore, the Koseny-Carman relation has been considered appropriate for determining the saturated permeability.…”

Morphology of U3O8 materials following storage under controlled conditions of temperature and relative humidity

“…Process variables inherent in the synthesis of nuclear materials are known to influence the morphology of uranium oxide products [4,[6][7][8][9][10][11][12][13][14][15]. In particular, comparison of the morphology of precipitates with those of subsequent calcination products suggests that microstructures of the precursor precipitates are retained through heat treatment [6][7][8][13][14][15][16].…”