[ben_w]

> Well, apparently they've had (lots of) the raw material for years.

"raw material" != "material".

While I assume they could've purified enough of the former into the latter by this point if they wanted to, it is a much much harder thing to do than to say.

> Marie Curie purified plutonium all by herself before the turn of the century (albeit in minuscule amounts at high personal cost), so I have little confidence in your assessment.

No, what she discovered was *polonium*, not *plutonium*.

She named polonium that in support of the nationhood of Poland (which was at the time was partitioned between three countries), despite discovering it she never actually isolated it because polonium has a half life of 138 days which makes it a really really small fraction of the total material.

Polonium was first isolated in 1902 by Willy Marckwald who managed a whole 3 milligrams and even then it took another three years for people to realise what he'd isolated was the same thing Marie Curie had found. It took 15 tons of pitchblende to get those 3mg.

*Plutonium* on the other hand was first discovered in 1934. Plutonium (and uranium) is the stuff that makes fission bombs. It takes tens of kilograms of uranium or plutonium per bomb.

Purification of chemical elements (both polonium and plutonium) is much, much easier than separating the isotopes of uranium; and you need to purify ("enrich") uranium to a specific isotope to manufacture more than trivial quantities of plutonium. (And, indeed, polonium).

> Unfortunately I believe this is just wrongheaded. When I was a kid I read Flash Gordon cartoons. There was an episode with "cobalt bombs" to wipe out a civilization permanently. One of the few times that I was freaked out as a kid. Nuclear war didn't scare me at all, but cobalt bombs and extermination - sheeeeeeit!8-(

You're taking a comic book plot device as evidence?

Also, cobalt bombs != dirty bombs:

A cobalt bomb is a bomb powered by a nuclear explosion, that has enhanced fallout.

A dirty bomb is a normal, non-nuclear, explosive, that has some radioisotopes attached to it.

The former easily wipes out a city; the latter messes up a building.

[giardini]

Thanks for the history corrections and clarifications. Now I'll never forget that Mme. curie isolated polonium (another nearly-useless factoid). History is important but not as important as science. Still you're looking more and more like Frank Drebin: "Nothing to see here, folks, move along!"

https://www.bing.com/videos/riverview/relatedvideo?q=google....

ben_w: "You're taking a comic book plot device as evidence?"

I was telling a story about my early life! Get a grip! It was a lead-in to a)the Soviet doomsday device which may have been real and may still be around and b)to my early fright at the nasty side-effects of nuclear weapons.

ben_wL "The former easily wipes out a city; the latter messes up a building."

Indeed an understatement! The Chernobyl reactor is an accidental "dirty bomb". It FUed quite a large area: people don't do much picnicking in the Chernobyl Exclusion Zone:

https://en.wikipedia.org/wiki/Chernobyl_exclusion_zone.

Spare me talking about how large the Chernobyl reactor and how heavy its fuel rods are, etc. Fissionable material and fission by-products are generally toxic: spreading it around is devastating and difficult to correct. And the Iranians have lots of that kind of crap.

[esseph]

> History is important but not as important as science.

Bullshit. Without historical data, you can't recreate experiments!

[giardini]

esseph sez "Bullshit. Without historical data, you can't recreate experiments!"

Why bother posting such nonsense?

[esseph]

Bullshit. Without historical data, you can't recreate experiments!

[ben_w]

> Thanks for the history corrections and clarifications. Now I'll never forget that Mme. curie isolated polonium (another nearly-useless factoid). History is important but not as important as science. Still you're looking more and more like Frank Drebin: "Nothing to see here, folks, move along!"

Sarcasm noted, but you were mixing up something that wasn't isolated by Curie because it was too hard to do so, with something that was only found in the year she died.

> Indeed an understatement! The Chernobyl reactor is an accidental "dirty bomb". It FUed quite a large area: people don't do much picnicking in the Chernobyl Exclusion Zone:

If you gathered all the nasty decay products from Chernobyl and put them into convenient balls to strap to an explosive for the purpose of messing up someone else's country, you'd immediately have a problem of *the balls would cause the explosives you put them next to, to catch on fire, because of the heat output of their own radioactive decay*. Even in the spread-out form of the real life incident, robots stopped working when they got too close to large concentrations, the radiation fried circuits.

You are scared of something that is not only not plausible, it's something such that if they could do it at a scale big enough to hurt you, they'd have better things to do, e.g. hitting the US warships counter-blockading Hormuz.

> Spare me talking about how large the Chernobyl reactor and how heavy its fuel rods are, etc.

Spare you the most important point?

> Fissionable material and fission by-products are generally toxic: spreading it around is devastating and difficult to correct. And the Iranians have lots of that kind of crap.

You say "lots" like it's a point, but it isn't: "lots" is far too vague.

Chernobyl had nearly 3000 times as much uranium in it as a fission bomb, to a different enrichment level, but how much enrichment matters during a criticality incident which transmutes elements into the nasty radioisotopes that you don't want to be around is complicated for fallout calculations. Nobody, including SpaceX, has a missile that is big enough to carry that all in one go.

  At the time of the accident in the reactor of the fourth power-generating unit of the Chernobyl nuclear power plant on April 26, 1986, the core contained 1659 fuel assemblies. Each assembly contained 114.7 kg of uranium, and therefore the reactor contained a total of 114.7 x 1659 = 190,287.3 kg of uranium. If the amount of fuel is calculated according to the uranium dioxide, i.e. in the form in which the fuel was loaded into the fuel elements, then its mass in each fuel element was 3.6 kg. A fuel assembly consists of 36 fuel elements, and therefore the reactor contained 3.6 x 36 x 1659 = 215,006.4 kg of uranium dioxide. The investigations performed in the destroyed buildings showed that the nuclear fuel after the accident is found in three main modifications: in the form of uranium dioxide tablets, in the form in which it was loaded into the reactor; in a dispersed form as dust and aerosol; and in a remelted state, in the form of a lavalike fuel-containing mass. This paper discusses the amount of nuclear fuel in the lavalike mass at the Chernobyl Nuclear Power Plant.

- https://www.osti.gov/biblio/226794

In comparison, the one which levelled Hiroshima contained 64 kilograms: https://en.wikipedia.org/wiki/Little_Boy

This scale difference is also (one of the reasons) why even having a nuclear reactor as a "civilian program" is suspect. Makes it relatively easy to hide a weapons program.

Much, much more effective to use the reactor to transmute yourself some plutonium, than a dirty bomb. Apart from anything else, half the plutonium won't vanish in 30 years (caesium-137) / 28.9 years (strontium-90) / 8 days (iodine-131) like the main Chernobyl fallout is doing.

[giardini]

OK, so you seem the proper nerd to ask something I've been wondering for a long, long time: the world has tons of nuclear weapons. Each consists of at least one fission component and an optional thermonuclear component. Let's concentrate on the fission part.

Q. Would it be possible to economically move the fission component into a standardized nuclear reactor that could then generate electrical power?

IOW is there a "swords to plowshares" solution to the disposal of fission weapons or, once you've made one, are you stuck with a device that can only be used to blow things up?

Reason I ask is, I see Russia et al sitting on all these weapons which cost a great deal, are no doubt costly to maintain and of little or no benefit to anyone (well, other than as a threat). [I mean, it's almost like owning a fleet of BMWs but even less useful! ] If we could build a "reactor framework" into which we could move a single warhead's fuel and that fuel could generate electrical power until sufficiently diminished to be of little/no use as a weapon, then that would IMO be a very good thing. Countries like Russia who had a closet of nukes but no money could sell the nuclear fuel off and benefit, buyers could get electrical power cheaper(?), and the world would be better off. Everybody wins.

Or is making a nuclear weapon effectively an economic one-way street (i.e., you're stuck paying for it forever?

[ben_w]

Weapons-grade uranium is easy to blend down into lower grades. Once you've got all the safety protocols you need because nobody wants to risk the theft of the weapon part, the down-blending process is just "break apart the metal and keep in small chunks so nothing gets close to critical while you do this, mix with similar sized chunks of depleted or natural uranium, melt, stir".

Plutonium is its own special thing, and I don't know much about its use in reactors: while it's definitely possible to use as reactor fuel, I can't speak to the cost or effort required. Apparently plutonium is a PITA when it comes to metallurgy, but while this makes it hard to process into a weapon, I don't know if it also makes it hard to process back to fuel.

[giardini]

So theoretically, Russia could begin converting their nuclear warheads to heat-generation units that could be used for all sorts of purposes. What kind of safeguards would be required?

The Russkies have lots of nukes but no cash. They're apparently as money-illiterate as I am, which is pretty awful. But if converting warheads to "heaters" (for everything from heating to power generation) would be worth a fortune, then it might be enough to rebuild Russia's economy.

Furthermore, it might be a way to save OpenAI by creating cheaper power supplies for AI datacenters [just kidding about this last one - always like to get the AIers excited, see if their stocks rise!].

[ben_w]

> So theoretically, Russia could begin converting their nuclear warheads to heat-generation units that could be used for all sorts of purposes.

They already did: https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program

A little too well, in fact, undercutting other suppliers; to quote from the page:

   The program was credited for being one of the most successful disarmament programs in history, but its low set price for nuclear fuel caused Western companies to not invest in uranium refining capacity, resulting by 2022 in Russia's government-owned Rosatom becoming the supplier of about 50% of the world's enriched uranium, and 25% of the nuclear fuel used in the US.

> What kind of safeguards would be required?

Mostly the classified security measures kind of safeguard: Make sure nobody can come in and steal the hard-to-make enriched weapons grade stuff before it gets blended down.

For material handling, everything I've heard about uranium as a metal is fairly mundane. Just:

• don't ingest it, lick it, or sniff it, it's an alpha emitter and a heavy metal

• don't grind it while you work on it, not only do you not want to breathe in a dusty alpha emitter, the dust is pyrophoric, i.e. catches fire in air https://en.wikipedia.org/wiki/Pyrophoricity#Pyrophoric_mater...

• and make sure the weapons-grade chunks are not ever under any circumstances near each other while working on them, for which the main big surprise is "do not work them into cylinders, because cylinders can roll towards each other and end up touching".