[ RadSafe ] In Soviet Russia, you enlighten p-versus-T diagram of uranium-oxygen system

James Salsman james at bovik.org
Tue Aug 8 21:22:11 CDT 2006

> > Levinskii, Y.V. (1974) "p-versus-T Phase Diagram of the
> > Uranium-Oxygen System" Atomic Energy 37(4):1075-6 is at:
> >
> >  http://bovik.org/du/Levinskii74.pdf
> >
> > Please correct me if I'm wrong, but that looks pretty clearly like
> > uranium trioxide reaches 1 atm of partial pressure at about 1300
> > degrees Celsius.
> >
> > Sincerely,
> > James Salsman
>   Aug. 8
>          And your point is . . . . .?
> Steven Dapra

It's a substantial combustion product.  Dr. Alexander was right.

I think that the actual partial pressure in air (80% N2) is about
7E-7*e^(Kelvins/135) mbar, per data from two different sources
(spanning 50 years) plotted here:


The temperatures increase as the burning particles get smaller,
with most of the burning surface area consumed between 2500
and 3000 K:


There is now absolutely no question that uranium trioxide gas
is a major, if not the major, combustion product of uranium in air.
It isn't detected because when it condenses, for the portion that
does not remain dissolved in air, it decomposes almost entirely
to U3O8.

And now there is no excuse for the military not measuring the
gas combustion products, which they still haven't.

James Salsman

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