Comment by qbasic_forever | Hacker News Reader

Comment by qbasic_forever | Hacker News Reader

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It turns into a modest dirty bomb of weapons grade plutonium. This isn't actually as nasty as it sounds--in the 80s Iraq and Saddam Hussein apparently did a lot of research and testing of actual dirty bombs and found they really were not effective at all (they weren't even found to be likely to kill anyone, it would just make a small area slightly hot radioactively but was easily cleaned up like any other small nuclear fuel mishap/incident). Initiating the full nuclear chain reaction takes a very specific and controlled process which would not occur without the bomb intending it to happen.

In the 80s a Titan 2 ICBM in the south actually exploded in its silo from a fuel mishap. The missile had a full hydrogen bomb on board and it was blown out of the silo and into a nearby field, still intact and unexploded. So in practice we've seen there's low risk for an unintended chain reaction. This is a great documentary on the incident: https://www.pbs.org/wgbh/americanexperience/films/command-an...

The book Command and Control by Eric Schlosser is one of the best I've read on any subject. He intersperses the history of nuclear command and control with the AR missile silo near disaster story. Top notch reporting all around.

Great book. He describes one related event: turns out the US did approximately this dirty bomb scenario once over Spain by accident. The plutonium pulverized to dust and they had to evacuate 3 square miles of farm land.

That was in Palomares. Funny thing is, in German supermarkets you often see tomatoes from there.

Edit: s/Europes/German. Don't know about other european countries. And would think of it as unlikely for Greece, Italy, Portugal, and Spain itself. They wouldn't import from there, and keep the good stuff for themselves, anyway :-)

How would that dust be cleaned up? Some kind of vacuum cleaners or is there a different way to neutralize the radioactive dust?

With accidents like Chernobyl that vaporized enormous amounts of radioactive material and deposited it all over nearby forests, roads, etc. as I understand they sprayed the areas with a sticky tar-like substance to keep dust clouds from kicking up, then brought it bulldozers and removed the top few inches of soil and moved it to a dedicated waste disposal area (packed it up in sandbags and buried it).

For a non-critical bomb exploding the bomb material actually has a pretty short half life on the order of a few decades or so I believe, so even if you did nothing at all the debris would naturally decay down to background levels fairly quickly (i.e. it would not be some catastrophic thing that ruins a part of the planet for centuries).

The fission primary of all the bombs in the US arsenal is mostly Pu-239, which has a half-life of 24,000 years, and a small but substantial fraction of Pu-240, which has a half-life of 6,500 years. They're both alpha-emitters, but Pu-240 also spontaneously fissions. Spreading a bunch of those around would not be great.

You are probably thinking of the tritium neutron trigger, which has a half-life of 12 years and has to be replenished to keep the warhead operational.

Does this imply that we have to constantly re-enrich and replace the warhead materials every few decades as well?

Yep, all of the nuclear weapons in the world are slowly decaying into obsolescence. They actually used to test fire them underground up until the early 90s to make sure older weapons were still working as expected. But underground weapon testing was banned and as I understand they just rely on computer simulations and non explosive tests to verify the weapons still in the active stockpile are working.

I'm not sure what the plans are for making new weapons in a few decades as the current ones decay into uselessness--there's likely some kinda provision in nuclear weapon treaties.

Indeed, this is actually the motivation for the National Ignition Facility at Lawrence Livermore. The accomplishment of demonstrating net-positive fusion was announced with an "atoms for peace" spin, but it really signaled to other nuclear powers we can do quite a bit of R&D without mesoscale detonations.

The US is already rebuilding many of its warheads. The process is ongoing but is estimated to take 30 years or so and cost about $1tn. It will presumably not require actual weapons tests, just component tests and simulations. I would assume that other nuclear-armed nations are doing the same things, if they have the financial resources (not all of them necessarily do.) https://en.m.wikipedia.org/wiki/Renovation_of_the_nuclear_we...

It fell into the sea. Sea currents moved it away long time ago.

at worst. Could "just" fall down and leave some radioactive junk.

For "proper" dirty bomb, the warhead would have to be exploded either by hit from AA weapons or by misfiring with damaged warhead but if AA just put some holes in missile and disabled propulsion it could be much less dangerous

“Just” is doing a lot of heavy lifting there.

Igniting a nuke is very difficult. 'just' is appropriate here.

> if [Anti Aircraft] JUST put some holes in missile and disabled propulsion it could be much less dangerous.

It's very very hard to hit a missile in flight. Trying to target just the propulsion is even harder. An admirable goal, but in the moment, especially because a lot of missiles are cluster munition and in a nuclear strike there's going to be multiple missiles flying all over the place.... Yes... just hit the propulsion. Heck, just target the guidance computer. Even better, just hit the CPU. Problem solved. Hopefully they figured that out.

It is correct that it’s hard, but the answer depends on what kind of flight. Hitting something with a missile that’s moving 1,000MPH is a lot more realistic than something that’s moving 10,000MPH. This makes re-entry a problem but hitting missiles that just took off somewhat plausible.

> just hit the CPU

EMP should do it. But otherwise, your point taken.

Nuclear missiles are heavily shielded and rely on inertial navigation, so they need no outside source like GPS, radio, etc to get to their target. An EMP would not stop one.

Which is why I put it in quotes. It's bad, but not "whole city dead" bad.

Shooting down nukes is always an everybody dies. MAD and all that. You can shoot down 98%. 2% still kills everybody. You can compartmentalize a hypothetical of one missile but that doesn’t take into account how our systems are designed to work.

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