Yet Another DEADLY RADIATIONS Rant

[funranium]

More than a few friends sent this story from CNN my way with a modicum of panic and hope that I could explain things a bit more. 

Now that I am teaching radiation safety at a local community college in addition to my day job, it has been made very, very clear to me:

1. What little the average person knows about radiation has mostly come from movies and 30 second news blurbs.
2. The students that came to my class know how little they know and lay it squarely at the feet of shitty science-ignorant media reporting.

To a reporter acquaintance, I said to his shamed face "Science reporting would have had to have been informed reporting before it could have been slanted.  Most of what I read comes across as opinion piece at best.  This article definitely would have received an F if I got it as a student paper."

I think the highlight of inconsistency in this story is the statement in paragraph 2 "...authorities discovered the Uranium 238, known as yellowcake, in a garage..." versus the paragraph 13 "...will perform an expert analysis of the seized uranium to establish the enrichment percentage and the country of origin".  Paragraph 9  "...undercover policemen acquired less than one gram of the substance and sent it to the United States for analysis, which confirmed that it was uranium 238", if true means paragraph 13 is unnecessary and this whole story belongs in the Those Dumb Crooks section of the paper.

U-238 is nearly useless to a terrorist for inflicting actual damage.  It is, however, quite useful to scare the hell out of people.  The word uranium has bad connotations to the public.  You don't need to actually *do* anything with uranium or plutonium, you just have to say the words.  U-235, on the other hand, is your precursor to a Little Boy style A-bomb.  In natural concentraions, only about .72% of uranium is U-235 and it is a sumbitch to separate them.  See Also: the 2 billion 1940s dollars and 4 years of the Manhattan Project.

It's primary use is an extremely dense object.  It's about 20% denser than lead and therefor takes up less space for the same weight.  So, you'll find it in elevator counterweights and boat keels.  That same high density also means that it is excellent for radiation shielding.  Sure, it itself is slightly radioactive but it can stop a hell of a lot more.  The only radiation you end up seeing from a big block of uranium is the surface emissions, the rest of it is self-shielding.  Oh, the other big use for uranium metal is as depleted uranium (AKA: DU, which means most fo the U-235 has been extracted already) armor piercing munitions.  Uranium metal is pyrophoric (burns spontaneously on contact with air) and the rounds happily melt through armor plate at >1000C. 

The real problem with uranium is not its radioactivity, it's the chemical toxicity.  It is a heavy metal and behaves in the body just like the lead & mercury.  It bioaccumulates and destroys liver, kidney and nervous system function.  The body just can't process the stuff out.  This is why sending out soldiers to confirm kills where DU rounds were used is a Bad Idea.  Lots of breathable uranium dust around. 

Uranium is normally sold in its most chemically useful form for transport U3O8, AKA yellowcake.  Metallic uranium is pyrophoric, but yellowcake is fairly inert.  1lbs of yellowcake, which is 75% uranium, is $46.  This means it doesn't quite qualify as a precious metal.  It's more valuable than copper but a far cry from silver.

Thus, there is a very large discrepancy between market spot price and black market price stated in this article.  To me, if you are determined to ill intent, it seems far more reasonable to purchase on the open market, report your purchase as appropriate, and then Do Evil because you really don't give a shit if you're Doing Evil.  The safeguards are there to keep honest people honest; they don't do crap against the dishonest who don't care.

This does highlight my desire to do a Science For Reporters education requirement her for the journalism school here at Cal.  They got it wrong off the bat and thus confused you.  "Yellowcake" is a chemical form.  That has absolutely nothing to do with the enrichment level (how much U-235 is present vs. U-238) of the uranium.  Naturally occurring uranium is .72% U-235, depleted uranium is <.72%, low enriched is .72-4%.  You don't hit weapons grade until you get to 95% U-235.  But at any stage of the game these various enrichments could be in the chemical form of U3O8. 

Several million dollars makes more sense if it has been through high enrichment (20-40% U-235).

It's hard enough to convey chemistry to people.  When you try to tell them that the entire Periodic Table of the Elements is only one axis on the Chart of the Nuclides (the axis of # of protons vs. the axis of # of neutrons) so you can build all the isotopes, their eyes go funny.

Comments

[draggonlaady.livejournal.com]

I think there's a bit of confusion in your rant--the undercover agents purchased 1 gram, which they sent in for analysis, THEN the place was raided and another 1.8 kilos was seized. At least, that's how I read that article. Other than that, though, yeah. Do please push for a science for journalists course! And when you get there, try to get some medical folk on the panel, too. :)

[funranium.livejournal.com]

If the first analysis came back as depleted uranium, a phone call of "quit wasting our time" should have come back down along with permission to let any idiot willing to buy this go right ahead.

Of course, the real point here was they captured a smuggling ring. A not terribly competent one and/or one with false advertising, but a smuggling ring nonetheless.

[draggonlaady.livejournal.com]

Ah, I see the drift now. Yes, waste of time to go after the rest. But good, I suppose, that they got the weapons and fake passports off the market. No brides though. That's really the only thing worth buying from a Russian smuggling operation ;)

[nojay.livejournal.com]

Uranium isn't particularly toxic except in large amounts. Uranium oxide particles get expectorated from the lungs if inhaled, it doesn't dissolve in the digestive tract much either and there's no known pathway that would cause significant neural damage as it's not cumulative. There's a little damage to the kidneys if enough uranium gets into the bloodstream but that's actually quite difficult to achieve, usually requiring years or decades of exposure to, say, ore particulates in a badly-ventilated mine.

Lead is a lot nastier, a lot more biologically active and it IS cumulative but it's the light metals like beryllium, arsenic and even lithium that will do for you a lot faster and in more nasty ways than uranium. Plutonium is different and definitely more toxic than uranium biologically speaking but it doesn't come in a form you can dig out of the ground.

[funranium.livejournal.com]

You are quite correct. The biological effects of uranium are in the same group as the rest of the heavy metals, but functioning at lower committed fraction than mercury and lead, depending on uptake pathway. The biological retention of plutonium is in the body is actually less than uraniums but the radiotoxicity is a far higher concern for Pu; little may stay, but its more than enough. That's why we do chelation therapy for Pu, but generally not U.

But radiation is what people worry about from uranium. Reminding people of its other qualities are among the many things I get to do as a health physicist.