[ RadSafe ] Re: uranium smoke is a teratogen
Brennan, Mike (DOH)
Mike.Brennan at DOH.WA.GOV
Thu May 8 12:29:50 CDT 2008
For coal fired power plants, I don't believe the vapor pressures of the various uranium compounds are a controlling factor. The uranium molecules, in whatever oxidation state, would be entrained in the exhaust gases and ejected into the atmosphere from a system designed to disperse all material leaving the stack. In "cleaner" coal fired power plants where substantial amounts of particulate is scrubbed out of the exhaust, it is likely that some percentage of the uranium will also be removed. I would expect it to be at least as available for resuspension as DU combustion products.
"Only about 8 tons of uranium per year in the U.S. is released in airborne coal ash..." James, misrepresentations like this are a fair part of why you have less credibility than you might like. The relevant quote from the article you linked to is: "For the year 1982, assuming coal contains uranium and thorium concentrations of 1.3 ppm and 3.2 ppm, respectively, each typical plant released 5.2 tons of uranium (containing 74 pounds of uranium-235) and 12.8 tons of thorium that year. Total U.S. releases in 1982 (from 154 typical plants) amounted to 801 tons of uranium (containing 11,371 pounds of uranium-235) and 1971 tons of thorium. These figures account for only 74% of releases from combustion of coal from all sources. Releases in 1982 from worldwide combustion of 2800 million tons of coal totaled 3640 tons of uranium (containing 51,700 pounds of uranium-235) and 8960 tons of thorium." You chose numbers from a couple of decades ago rather than using newer numbers from the graph, you use the US numbers rather than the much, much larger world numbers, even though we are talking bout a world wide issue, and you seem to have applied a 99% discount rate, presumably to account for particulate precipitators removing fly ash, even though there is no indication that the authors have not already taken that into account. NOTE: I can not say for certain that they did, but I see several pieces of evidence (the lines on the graph being represented as smoke from a stack, for example) that the numbers they give are for airborne releases. Further, for the "world" numbers, it is known that many plants overseas do not have as effective controls on particulate as do US plants.
>However, coal plant smoke is responsible for most of the uranyl in the atmosphere right now, and most of the uranyl that has been breathed; but not any of the largest acute or chronic human exposures.
OK, now we are getting somewhere. I agree that coal smoke is responsible for most of the uranyl (indeed, uranium in any form) in the atmosphere right now, and for most of the uranyl that has been breathed. I am not sure I accept that there are not large acute exposure to people downwind of some of the worst offenders in foreign countries, though I readily accept that for those people uranium is not the highest health risk they are facing. I reject the idea that there are no chronic human exposures. I would contend that for you to argue that in the "chronic" exposure range DU is more of a problem than coal smoke you must reject the Linear-No-Threshold/Population Dose model, in which case you probably have at least some number for exposure below which you believe it is not of concern.
>If you do a Google News search on [depleted.uranium birth.defects] you will see that the Iranian press is more interested in the issue than the U.S. press.
I believe the Iranian press is more interested in no small part because the Iranian Government believes this is a topic in which they can incite anti-American feelings, and that the truth content is of relatively little concern. I also believe that the Iranian Government, which sent out human waves to clear mines and absorb bullet so their soldiers could attack Iraqi fortifications would not hesitate to make and use DU projectiles, once they had a bunch of depleted uranium sitting around.
>What more can one person do?
Be more interested in truth than advancing a political agenda. Guard one's credibility by arguing fairly.
>I am not affiliated with any "anti-DU forces."
Perhaps you should give it a try. You could become a voice of reason.
From: jsalsman at gmail.com [mailto:jsalsman at gmail.com] On Behalf Of Ben Fore
Sent: Tuesday, May 06, 2008 7:48 PM
To: Brennan, Mike (DOH)
Subject: Re: [ RadSafe ] Re: uranium smoke is a teratogen
Thank you for your good questions:
Mike Brennan wrote: "So does this mean that a coal fired power plant, especially one with inadequate exhaust scrubbing (as I believe describe most of those in China), which burns coal that has uranium in it (as most coal does, to one extent or another) is releasing uranium smoke with the uranium in the +6 oxidation state? Considering that there are a huge number of coal fired power plants, and their fires and uranium smoke production is ongoing, and the exposed population is truly huge, isn't this a far more important exposure concern than DU projectiles? And if you say it isn't, where is your proof that it isn't? (No reasoned arguments here: it has to be proof that Chinese uranium smoke isn't as bad as American uranium smoke)."
Coal fired plants do release uranium in the +6 oxidation state, but not much. I can't give you exact numbers for China, but I do have numbers for the U.S. Coal has uranium oxides (in the +4 oxidation
state) distributed uniformly, and it burns at under 1300 Kelvin, producing very little U(VI). The vapor pressure of UO3 at 1250 K is only 1e-5 mbar, so not much makes it airborne. Only about 8 tons of uranium per year in the U.S. is released in airborne coal ash ("This uranium is released to the atmosphere with the escaping fly ash, at about 1.0% of the original amount [800 tons/year U.S.], according to NCRP data." -- http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html
) A tiny fraction of that is uranyl; I would guess far less than 10%.
And most of that, if it isn't scrubbed, weathers before being inhaled. So how many coal plants are there in the U.S. pumping out that < 0.8 tons of uranyl per year?
The difference between the airborne soluble uranyl concentration in coal plant smoke spread out over the country and uranium smoke in the region around a DU-against-metal firefight is a huge difference. When metalic uranium particles burn in air, the temperature exceeds 2800 K (Mouradian and Baker (1963). "Burning Temperatures of Uranium and Zirconium in Air". Nuclear Science and Engineering 15: 388-394) which pushes the partial pressure of the uranyl production into the majority of the combustion product. At 2800 K, the vapor pressure of UO3 is a full atmosphere, 1000 mbar, or a hundred million times more volatile than at the burning temperature of coal.
However, coal plant smoke is responsible for most of the uranyl in the atmosphere right now, and most of the uranyl that has been breathed; but not any of the largest acute or chronic human exposures.
Mike Brennan also wrote: "Also, Iran is enriching uranium for its civilian power plant. This means that soon Iran will have a substantial amount of deplete uranium. Iran boarders two countries occupied by a hostile power with an army that has great superiority in armored vehicles. It is only reasonable to believe that Iran will soon start manufacturing DU weapons for its own defense (indeed, it is not at all impossible they have already started). Wouldn't NOW be an excellent time for the anti-DU forces to start bringing pressure to bear against Iran, to get them to promise to never make or use DU weapons? That way, if there is a war between the US and Iran, only one side will be using them, and thus limit the damage they will do."
If you do a Google News search on [depleted.uranium birth.defects] you will see that the Iranian press is more interested in the issue than the U.S. press. What more can one person do? I am not affiliated with any "anti-DU forces."
James Salsman, as Ben Fore
> -----Original Message-----
> From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
> Behalf Of Ben Fore
> Sent: Tuesday, May 06, 2008 10:26 AM
> To: radsafelist
> Subject: [ RadSafe ] Re: uranium smoke is a teratogen
> Thank you for your helpful question:
> > Since everyone on the planet has been exposed to natural >
> concentrations of uranyl ions, constantly, day after day after day for
> > their entire lives, how exactly is this so different from a brief, downwind exposure to smoke?
> U(VI) weathers to U(IV), and the proportion of natural uranium in world-wide average soil in soluble compounds in the +6 oxidation state is less than 0.01%, is it not?
> Whereas in uranium smoke, most of the uranium is soluble, and most of
> it is in the +6 oxidation state; at least 1/3 dissolves into the
> uranyl ion
> > And at what distance? Since the smoke should follow the behavior of
> a > Gauss "puff", as opposed to a "plume", after a kilometer or so of
> > diffusion the concentration is very low.
> I have studied the aerosol dispersion papers in Health Physics and the recent papers by R. Guilmette and M. Parkhurst. There is no doubt that someone in a typical 500 m downwind or 150 m vicinity of a 1 kg uranium fire will be exposed to thousands of times as much uranyl as they usually get in a month.
> But what good would it be if we knew the exact dose? We still have no idea what the effect is on any mammal with a nine-month gestation period ten years after such an exposure.
> That's why I keep asking everyone to try and get people to find out, please.
> > Once the dust settles, infiltration of rainwater will move it
> deeper > into the soil column along with all the other nicely-behaving, natural uranyl complexes.
> Which soluble U(VI) complexes remain after weathering? None.
> Mattias Olsson wrote:
> > The interesting post below reminded me about an old incident I've
> been > told about with radiation alarms being set off by the smoke
> from a > Danish coal fired power plant. The detector was placed at
> the > Barsebäck NPP site in Sweden, apparently in the plume. Burning
> stuff > that has been dug up from the ground seems like a nice way to
> spread > uranium. Or did, before modern filter technology anyway.
> Do you mean radiation alarms or uranyl alarms? While coal-fired plants make a huge contribution to the amount of uranyl in the atmosphere (though not approaching being in the vicinity of 30 mm DU autocannon fire), they have not increased soil concentration of uranium much above 1600 levels, because U(VI) weathers to U(IV).
> James Salsman
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