[ RadSafe ] Re: uranium smoke is a teratogen
Dan W McCarn
hotgreenchile at gmail.com
Sun May 11 15:44:03 CDT 2008
Dan W. McCarn, Geologist; 3118 Pebble Lake Drive; Sugar Land, TX 77479; USA;
HotGreenChile at gmail.com UConcentrate at gmail.com
I make no such assumption, but you seem to have your language about what constitutes "weathering" completely upside down. "Primary" (reduced) uranium minerals "weather" to "secondary" (oxidized) species. This reaction involves the exchange of electrons and constitutes a redox reaction. Reduced uranium species are virtually insoluble e.g. uraninite with a 10^-12 molar solubility. Oxidized species have far greater solubility.
UO2(s) as uraninite oxidizes to become UO2+2, attaches two hydroxl ions, and becomes UO2(OH)2:H2O(s) - Shoepite. Shoepite reacts with the bicarbonate in water (CO2 reacts with water and speciates to form a weak diprotic acid - H2CO3 which speciates to HCO3- and CO3-2) and becomes an anionic aqueous species UO2(CO3)2-2(aq) in groundwater at neutral pH values. This reaction is quite fast, if you've ever taken the time to observe it. The kinetics are so good, in fact, that it allows ISR/ISL mining on a commercial scale. Head grades for production wells are several hundred milligrams per liter uranium (mg/L U).
You should buy Doug Langmuir's book on geochemistry; and get a copy of PHREEQC.
3,000 "acute" exposures... I'm surprised they survived at all with the KE of the shrapnel. Or go back and look at the uranium mill worker exposures and outcomes. As I recall, they had a less than average chance of mortality with liver / kidney / heart disease...
And don't include me in that royal "we" that you mention.
From: James Salsman [mailto:jsalsman at gmail.com]
Sent: Sunday, May 11, 2008 2:44 PM
To: hotgreenchile at gmail.com; radsafelist
Subject: Re: [ RadSafe ] Re: uranium smoke is a teratogen
Thank you for your critique:
> Ben or James or whomever is wrong!
On the contrary, you assumed that UO2 would weather (water or
humidity) into UO3, when in fact UO3 weathers into UO2.
The question that I hope one of us will be able to find out is: what
is the rate of that transition? This should probably be expressed
both in traditional terms and as the half-life of a single dissolved
UO3 molecule for purposes of elucidation.
The fact remains that uranium fire from DU munitions use has
caused about 3,000 of the most acute exposures. We need to
narrow the confidence interval.
James Salsman, as Ben Fore
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