Where to get depleted uranium?

Will do.

Nasty inside though. It's also a heavy metal like mercury and lead.

Tim

-- "California is the breakfast state: fruits, nuts and flakes." Website:

I don't believe that for a moment.

Granite has sod-all radioactivity. Get a lump, try counting it - not easy, even with good tools. The risk from granite is because it's found in large underground masses and the daughter product is a gas. This can travel, so if you have a house with a suitable basement and no ventilation then you can be concentrating the radon from a huge quantity of rock. If you live in a stone-built house on pillars though, no hazard at all.

You start out by thinking what on earth you want it for. Then you buy the right sort. You also need to read up on radiation, its monitoring, its hazards and its devices. This is _not_ a simple subject (although reading military training pamphlets is often a good simple start - the relevant FM is probably on-line)

If you buy a mil-surplus G-M then you have three problems; it's insensitive, because it was designed for measuring fairly high rates. Secondly it's _really_ insensitive, because it's 30 years old and the tube has gone soft - GM tubes age badly, especially those sensitive to beta. Thirdly it's likely to run on valves and require some weird 90V battery that's no longer available.

So if you want to play science, buy a brand new (or still-boxed surplus) tube and build yourself a transistor power supply and counter circuit for it.

Here in the UK, the military didn't use that many G-M devices. The standard battlefield meter was an ionisation chamber device, because this is more appropriate for military levels. For training there was a very similar meter, except it was a different case colour (black and silver). This did use a G-M tube and was sensitive enough to sniff out small training sources, pinned to a squaddie's battledress.

For civil defence use, the standard device was a G-M tube mounted above one of the ROC's bunkers.

were also hand-held variants (cream metal cases)

In later years these were all replaced by variants of the ubiquitous Plessey PDRM82

are still around on eBay ($50 street price) and the surplus market (Bull electrical) as good NOS. They're robust, they use common batteries, they;re just the ticket for environmental monitoring and best of all they're PDRM82's. It's a problem with low-level env radiation monitoring that calibration is a Black art and the only way to get decent results is for everyone to be using the same meter.

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Interesting. DU must have about the same specific gravity as gold. (Slightly higher, I'd guess)

Gold = 19.32 Depleted Uranium = 18.7

Well... slightly lower, then! :^)

That "d" word obviously makes all the difference...

Hm. That's interesting, because I played with the Geiger counter last night (technically a "Scintillation Meter"), and found the following:

Radiation survey of everyday objects:

Background radiation, 4 sites inside house: 1.5 Counts per Second (CPS) Background radiation, 4 sites outside house: 1.5 CPS

4 over-ripe bananas, sensor in contact with skin: 3 CPS Clean diapers: 1.5 CPS (no detectable radiation; same as background) Dirty diapers, measured at top of diaper pail: 2 CPS 6 month old kid: 1.5 CPS plus drool and two giggles "First Alert" smoke detector, with Americium goodness: 50 CPS on surface 10 year old Trijicon (Tritium) gunsights on Glock 19: 1.5 CPS Granite boulder, roughly 1 meter in diameter. Pink: 4 CPS Black: 3 CPS Blue/black boulder of unknown ignious type: 1.5 CPS Garden soil: 1.5 CPS

Obviously this is only a slightly scientific survey, but shows some interesting non-background results.

Right. Measurable doesn't mean dangerous. Well, except in the case of the diaper pail above (trust me on this one). For the record, the kid just started on bananas. I should check his other foods, just out of curiousity.

Dave Hinz

Dave, thanks for quatifying the radioactivity with your experimentation. You have proved that granite and banananas are indeed radioactive. The level is indeed low but it is there for those that are hypersensitive to the idea of radioactivity. For fun with hypersensitivty to radiation, carve yourself a key fob out of granite and when you meet one of those idiots, show it to him and then tell him that it is radioactive. Then watch him freak.

-- Why isn't there an Ozone Hole at the NORTH Pole?

Thanks for the report Dave! :) -Alvin

For those who over-react to non-issues, I hope you mean?

Heh. I think the fact that baby poop is measurably radioactive is fun enough.

Some of the aircraft I have worked on over the years have had DU in them as mass balance weights for flight controls.

It is relatively benign. We were under strict guidance to not drill, grind, or otherwise alter the weights. There were procedures in place that dealt with crash salvage and recovering the weights for disposal, if it was required.

I am under the impression that the OP is suffering from a bad case of ignorant, and perhaps should do his own homework to see if he really wants to deal with the stuff. If he wants heavy, lead is probably his best bet for safe and easy. Maybe solid tungsten, if he has the budget.

I expect that if the OP were in a position to actually require DU, he would already know the risks vs. the benefits, as well as the sources.

Cheers Trevor Jones

Hmmmm, if these dupes carry around counters, you could have some good fun.. like drill out a few smoke alarms and encase the bits in a plastic fob like you said. Radiation ought to be negligible enough (with the alphas contained in the plastic and protected by skin and pocket lining), yet still detectable.

Or if you've broken a bright orange ceramic dish, it might be a uranium colored glaze - those set off a counter too.

Tim

-- "California is the breakfast state: fruits, nuts and flakes." Website:

Naw...go for the cheap and easy route. Coleman lantern mantles.

That's probably a better way to put it.

-- Why isn't there an Ozone Hole at the NORTH Pole?

I guess that's Be10? Half life = 2.7x10^6 years, beta-0.56; no gamma Abundance is listed as zero in my book tho. :/

The problem with those was ordinary Be in the lungs. Do they have another metal I'm missing?

Alvin in AZ (panix here too;)

Cerium

Ned Simmons

Nah, actually thorium has the highest melting point of any oxide. I forget what it is offhand, something like 3000 or 3200°C?

Ceria may've replaced it nowadays...that wouldn't be suprising. I'd think something like zirconia or magnesia would be cheaper while still retaining the high melting point, though. Must be the emission spectrum of the rare earths that they need.

Tim

-- "California is the breakfast state: fruits, nuts and flakes." Website:

Apparently a mixture of thorium and cerium oxides.

Ned Simmons