Vacation Throughput: Video, Plus Don’t Shoot The Nuclear Reactor Edition
So I’m on vacation this week with the family. Thus, a rather abbreviated Throughput for today, the main part of which is my most recent appearance on Andrew’s Heard Tell show. These appearance are always fun and we get to talk about the upside of Starlink, the dangers of asteroids and the road ahead on COVID-19.
In addition to that, here’s a few stories to chew on:
[ThTh1] The first planets we ever detected were around the husk of a dead star. We’re still detecting them.
[ThTh2] Learning more about the Iceland crater discovered a few years ago.
[ThTh3] The Omicron waves are receding globally. But, as I discuss in the video above, that does not mean we can become complacent. “Endemic” doesn’t mean harmless. Nor does it means that we casually accept a few hundred thousand deaths every year. Now is the time to gird up for the long haul.
[ThTh4] Maybe … maybe, we don’t fire cannons at the nuclear plant.
[ThTh5] We’re learning more about how COVID affects the brain.
One thing that I was wondering was the half-life of the various materials used in nuclear warheads.
I was hoping that something that would have a half-life of around six years was used. I mean, if the last big warhead was made in 1992 and the half-life was six years, then… well, 1998, then 2004, then 2010, then 2016, then 2022.
Five half-lives gets you from 100% to 50% to 25% to 12.5% to 6.25% to 3.125%.
So a 100 megaton bomb becomes a 3 megaton bomb. I felt a moment of relief.
As it turns out, google tells me that most warheads use plutonium-239 and uranium-235.
Plutonium-239 has a half-life of 24,100 years.
Uranium-235 has a half-life of about 700,000,000 years.
Bummer.Report
Modern warheads are fission-fusion-fission designs. Maintenance involves refreshing the tritium for the fusion stage. Tritium has a half-life of about 13 years.Report
13 years is much better than 700,000,000.
I’m relatively certain that the ones in the US silos have been maintained.
Looking at the tires of the various Russian trucks in the various ditches in Ukraine has me wondering about the maintenance of the ones in other silos out there.
Fission-fusion-fission will have different math than back of an envelope half-life calculations though. If I assume that the reaction is exceptionally fragile, that gets me to a great deal of relief. If I assume that, nah, that part ain’t the part that is exceptionally fragile, then that gets me more or less back to where I was.
Maybe I could assume that the electronic parts have been about as well-maintained as the tires were…Report
There are all sorts of things to worry about before you get to half-lives. Deterioration of the chemical explosives. Problems with the sub-microsecond detonators that set off the chemical explosives. The electronics that fire the detonators. There are reasons the DOE spends billions each year on nuclear warhead maintenance. In some cases that have shown up, failure to keep exact design and upgrade records properly.
A few years ago the Air Force put out a request for bids for someone to take two sample circuit boards, reverse-engineer them for function, then design replacements using contemporary components. A friend who used to do Air Force procurement said, “Yeah, they lost all the copies of the spec and are down to a handful of replacements. Probably old B-52 sh*t.”Report
The electronics are within a few yards of stuff that is spitting out radiation. It’s probably well-shielded against alpha particles and you only need an inch of plastic or something to shield against beta ones.
Sitting that close to a gamma particle source isn’t good in the medium term for electronics. Right?Report
Slightly-informed guessing here, but the first thing to worry about is just effects of aging. Shaped blocks of high explosive. Exploding bridgewire detonators. High-voltage tube devices. Capacitors. All in steel containers that are going to be banged around and subjected to temperature swings. So you ask, after 20 years, will all those things still function as designed with sub-microsecond accuracy?
They had to invent all kinds of odd non-nuclear stuff to make implosion fission bombs work properly.Report
Yep. Pretty much everything involved needs to be constantly maintained and replaced. They’re not going to simply work years or decades later without it. I’m sure somewhere in the DoE is a nice curve showing exactly what the failure rate is over time for any given type of nuclear bomb.
The more complex the bomb (which mostly corresponds to either “real big boom” or “really small package”), the quicker it’d go bad.
My guess would be the same as yours — well before you needed to replace the nuclear material, you’d need to test and replace all the bits that make sure the explosion in a very specific shape, at an insane level of timing.
Nuclear bombs aren’t, by and large, difficult to make — the sort of tolerances are in line with a lot of industrial practices and the physics simple enough that sufficiently bright college kids can design one.
Maintaining it is hard and expensive.
That doesn’t get into the delivery vehicles — ICBM’s are incredibly complex and “via missile” (intercontinental or otherwise) is pretty much the preferred method of delivery.
Russia has the capacity to build, repair, and maintain ICBM’s (they launch vehicles to the ISS, after all) — or they did. I’m not sure how many components they import for those.
Same with nukes.
The question is…did they?
I wouldn’t gamble on them being non-functional, but I would suggest that a weapon they have no plan to actually use (where simply knowing they have it is a powerful deterrent) is probably low priority for spending in a corrupt kleptocracy.
Russia’s last nuclear test was in 1990.
I have been expecting Putin to arrange a nuclear test to remind the world that Russia is a nuclear power as his invasion of Ukraine continues to be such a…challenge…to the views of Russian military might.
My best guess is it will be around the time Russia declares victory and withdraws.Report