[ RadSafe ] Salsman's uranium trioxide gas proof

[Otto Raabe]

At 12:59 PM 1/24/2007, you wrote:
>Are you suggesting that as a gas diffuses and cools below the point at
>which it is volatile, more than half of it will condense
>"instantaneously?" That is absurd.
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When the oxide molecule forms by "burning" liquified plutonium or uranium 
it has different chemical and physical characteristics that the pure metal. 
Cooling is virtually instantaneous even near the combustion process and 
results in all (not half) of the vapor being converted to solid oxide 
particles. These particles rapidly coalesce into chain aggregates as shown 
in the micrographs in the paper by Carter and Stewart or my own studies 
referenced below. This is virtually an instantaneous process since the 
melting and vaporization temperatures of the oxides are much higher than 
those of the pure metals. Hence, the "vapor" form of the oxides only exists 
momentarily, if at all,and only if the reaction is hot enough to reach the 
oxide melting point.

I have conducted these types of experiments and characterized the particles 
produced by laser vaporization of plutonium. The vapor oxidation and 
particle formation is virtually instantaneous. The vapor phase exists only 
in the superheated zone. [Raabe, O.G., S.V. Teague, N.L. Richardson and 
L.S. Nelson. Aerodynamic and dissolution behavior of fume aerosols produced 
during the combustion of laser-ignited plutonium droplets in air. Health 
Physics 35: 663-674 1978.].

Otto



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Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
University of California
One Shields Avenue
Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754   FAX: (530) 758-6140
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