6 ms·

Max warheads = 31k Current warheads = 3.7k I wonder how long a nuke in storage lasts - ie, how much work does it take to maintain a stockpile of x nukes, and

Max warheads = 31k Current warheads = 3.7k I wonder how long a nuke in storage lasts - ie, how much work does it take to maintain a stockpile of x nukes, and if you can turn those swords into ploughshares relatively easily.

nulltxt 2y ago
https://www.youtube.com/watch?v=N2OUzBrLEFk https://www.youtube.com/watch?v=N2OUzBrLEFk is a interesting video about the transport of these weapons
mikewarot 2y ago
Plutonium pits slowly transmute, and the emitted alpha particles are trapped and form helium bubbles. They have to be replaced periodically.
- wdh505 2y ago
  I think the tritium "preignition" has to be replaced every 10 years.
jiggawatts 2y ago
> how long a nuke in storage lasts Decades, certainly. All but the first few generations of bombs were designed for long periods of storage. Notably, many of the TOP500 supercomputers were built with the singular goal of simulating the ageing of nuclear weapons in storage. If a supercomputer is owned by the DoE or SANDIA, then that's what it is for. > turn those swords into ploughshares relatively easily. Yes! Cold-war era warheads from both the Soviet Union and the US have been used as nuclear fuel. A notable one was the Megatons to Megawatts program: https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program The plutonium in bombs is essentially "super high grade" reactor fuel. Even degraded after decades in storage it is still far, far better than what is typically used. It just needs to be converted into the MOX (metal oxide) fuel pellets and then used in a reactor, pretty much as-is.
- dekhn 2y ago
  While many supercomputers were funded by stockpile stewardship, the goal was to produce high performance computers capable of a wide range of simulation needs. One good example would be NERSC at LBL- it's unclassified research only, and their series of supercomputers were never intended to simulate ageing nuclear weapons. Hard to say exactly what goes on in the classified supercomputers, but they certainly weren't spending much of their time simulating aging nuclear weapons- that was the ostensible reason.
philipkglass 2y ago
It takes quite a bit of work to maintain nuclear warheads. All active US weapons contain plutonium 239, which has a half life of 24,100 years. It's radioactive by alpha decay, which leads to changes in the material properties due to energetic collisions and the buildup of microscopic helium bubbles (alpha particles are merely ionized helium nuclei, so stopped alpha particles become helium). Since the US stopped testing actual nuclear warheads in the early 1990s, it takes a great deal of indirect theoretical and experimental evidence to make sure that nuclear warheads are reliable without live fire tests. That's part of "stockpile stewardship." [1] If the plutonium has deviated too far from its original mechanical behavior, it would need to be removed from warheads, purified, and remanufactured into replacements that match the original specs. And again, the rebuilt components need to be reliable but they can't actually be tested via explosion. US weapons also rely on tritium gas "boosting" to operate reliably and efficiently [2], and tritium decays with only a 12.3 year half life. The gas reservoirs of weapons need their tritium replaced at significantly shorter intervals. Even manufacturing enough tritium to maintain the stockpile has become a challenge because the US has retired its Cold War era weapons-material reactors that used to operate at Hanford and Savannah River. Currently the US uses a power reactor owned by the Tennessee Valley Authority to make tritium for weapons [3]. It's possible to make nuclear weapons (even thermonuclear weapons) with only uranium 235 for fissile material and no stored tritium. Such weapons could last a much longer time without active maintenance, since U-235 decays thousands of times slower than Pu-239. However, they would be larger and heavier for the same explosive yield, which complicates delivery. They would also lose certain safety features. Finally, without being able to perform full scale tests, it is doubtful that the US would have the confidence to replace its current high-maintenance weapons stockpile with a new generation of low-maintenance weapons. [1] https://en.wikipedia.org/wiki/Stockpile_stewardship https://en.wikipedia.org/wiki/Stockpile_stewardship [2] https://nuclearweaponarchive.org/Nwfaq/Nfaq4-3.html#Nfaq4.3.1 https://nuclearweaponarchive.org/Nwfaq/Nfaq4-3.html#Nfaq4.3.... [3] https://www.wvlt.tv/2022/05/24/watts-bar-lone-source-nuclear-weapon-material-tva-increasing-production/ https://www.wvlt.tv/2022/05/24/watts-bar-lone-source-nuclear... "Watts Bar lone source of a nuclear weapon material; TVA increasing production"
- Loughla 2y ago
  How do you know all this? Is that a hobby or a job?
openasocket 2y ago
I think it’s shorter than you would imagine. I recall an episode of the podcast Arms Control Wonk talking about the nukes in possession of Ukraine during the collapse of the Soviet Union. Professor Lewis stated that those warheads likely had a service life of 5-10 years. But that may be specific to those Soviet warheads, and I think that different components need to be replaced at different intervals.
jmyeet 2y ago
So this varies depending on what kind of nuclear weapon is and the delivery system. The major deterrant is the LGM-30G Minuteman III [1]. Most of our rockets use liquid propellants. Since the alert window is under 10 minutes, you can't keep a liquid-fuelled rocket permanently fueled so the Minuteman was developed as a solid rocket fuel booster. There's a whole team responsible for maintaining the boosters and warheads of this first line of defense [2]. But there are a variety of other systems. Some dropped by strategic bombers, others on mobile launchers, shorter range missiles deployed in Europe (eg MRBMs in Turkey), nuclear weapons deployed on submarines and so on. Also you have a mix of types. AFAIK the US was moved away from highly-enriched uranium weapons in favor of plutonium. Or at least, HEU reactors have shut down. Maybe there's a sufficient stockpile? Also, a lot of these weapons will be thernonuclear so you have to worry about the production and storage of tritium. IIRC a lot of tritium is a byproduct of plutonium production. Maintaining a significant nuclear arsenal is actually really complex and expensive. [1]: https://en.wikipedia.org/wiki/LGM-30_Minuteman https://en.wikipedia.org/wiki/LGM-30_Minuteman [2]: https://minutemanmissile.com/missilemaintenance.html https://minutemanmissile.com/missilemaintenance.html
- lmm 2y ago
  > Since the alert window is under 10 minutes, you can't keep a liquid-fuelled rocket permanently fueled so the Minuteman was developed as a solid rocket fuel booster. Huh? The Titan II was developed to do precisely that and worked that way for decades, they were liquid-fuelled and kept fuelled in their silos.
  - openasocket 2y ago
    Liquid propellants are generally less stable than solid fuel. I had read in multiple places (from reputable sources) that you generally couldn’t keep liquid missiles permanently fueled like that. The propellants are extremely corrosive and dangerous. But you are right that the Titan II is liquid fueled and was kept permanently fueled in the silo. I’m not entirely sure how to resolve those two facts. The Wikipedia page about the Titan II does mention multiple accidents and fatalities related to propellant leaks, so I’m guessing that they were just more risky to operate?
hollerith 2y ago
>I wonder how long a nuke in storage lasts Russia's nuclear stockpile -- at least the strategic warheads -- have all been built anew since the end of the Cold War. The US is also modernizing its stockpile in the same way, but it has not finished yet. "built anew": made with all new components except that the fissile material is recycled from an old Cold-War-era warhead. (They probably re-cast and re-machine the fissile material.) The reader might be asking, How can Russia, a poor country, afford that? Well, nukes aren't that expensive once you have the fissile material and the design and manufacturing expertise and infrastructure. The pay for the soldiers to guard the nukes and constantly be on the ready to launch them is more expensive, according to one report I saw recently (and Russia has low personnel costs).

nulltxt 2y ago

https://www.youtube.com/watch?v=N2OUzBrLEFk https://www.youtube.com/watch?v=N2OUzBrLEFk is a interesting video about the transport of these weapons

mikewarot 2y ago

Plutonium pits slowly transmute, and the emitted alpha particles are trapped and form helium bubbles. They have to be replaced periodically.

wdh505 2y ago
I think the tritium "preignition" has to be replaced every 10 years.

jiggawatts 2y ago

> how long a nuke in storage lasts Decades, certainly. All but the first few generations of bombs were designed for long periods of storage. Notably, many of the TOP500 supercomputers were built with the singular goal of simulating the ageing of nuclear weapons in storage. If a supercomputer is owned by the DoE or SANDIA, then that's what it is for. > turn those swords into ploughshares relatively easily. Yes! Cold-war era warheads from both the Soviet Union and the US have been used as nuclear fuel. A notable one was the Megatons to Megawatts program: https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program The plutonium in bombs is essentially "super high grade" reactor fuel. Even degraded after decades in storage it is still far, far better than what is typically used. It just needs to be converted into the MOX (metal oxide) fuel pellets and then used in a reactor, pretty much as-is.

dekhn 2y ago
While many supercomputers were funded by stockpile stewardship, the goal was to produce high performance computers capable of a wide range of simulation needs. One good example would be NERSC at LBL- it's unclassified research only, and their series of supercomputers were never intended to simulate ageing nuclear weapons. Hard to say exactly what goes on in the classified supercomputers, but they certainly weren't spending much of their time simulating aging nuclear weapons- that was the ostensible reason.

philipkglass 2y ago

It takes quite a bit of work to maintain nuclear warheads. All active US weapons contain plutonium 239, which has a half life of 24,100 years. It's radioactive by alpha decay, which leads to changes in the material properties due to energetic collisions and the buildup of microscopic helium bubbles (alpha particles are merely ionized helium nuclei, so stopped alpha particles become helium). Since the US stopped testing actual nuclear warheads in the early 1990s, it takes a great deal of indirect theoretical and experimental evidence to make sure that nuclear warheads are reliable without live fire tests. That's part of "stockpile stewardship." [1] If the plutonium has deviated too far from its original mechanical behavior, it would need to be removed from warheads, purified, and remanufactured into replacements that match the original specs. And again, the rebuilt components need to be reliable but they can't actually be tested via explosion. US weapons also rely on tritium gas "boosting" to operate reliably and efficiently [2], and tritium decays with only a 12.3 year half life. The gas reservoirs of weapons need their tritium replaced at significantly shorter intervals. Even manufacturing enough tritium to maintain the stockpile has become a challenge because the US has retired its Cold War era weapons-material reactors that used to operate at Hanford and Savannah River. Currently the US uses a power reactor owned by the Tennessee Valley Authority to make tritium for weapons [3]. It's possible to make nuclear weapons (even thermonuclear weapons) with only uranium 235 for fissile material and no stored tritium. Such weapons could last a much longer time without active maintenance, since U-235 decays thousands of times slower than Pu-239. However, they would be larger and heavier for the same explosive yield, which complicates delivery. They would also lose certain safety features. Finally, without being able to perform full scale tests, it is doubtful that the US would have the confidence to replace its current high-maintenance weapons stockpile with a new generation of low-maintenance weapons. [1] https://en.wikipedia.org/wiki/Stockpile_stewardship https://en.wikipedia.org/wiki/Stockpile_stewardship [2] https://nuclearweaponarchive.org/Nwfaq/Nfaq4-3.html#Nfaq4.3.1 https://nuclearweaponarchive.org/Nwfaq/Nfaq4-3.html#Nfaq4.3.... [3] https://www.wvlt.tv/2022/05/24/watts-bar-lone-source-nuclear-weapon-material-tva-increasing-production/ https://www.wvlt.tv/2022/05/24/watts-bar-lone-source-nuclear... "Watts Bar lone source of a nuclear weapon material; TVA increasing production"

Loughla 2y ago
How do you know all this? Is that a hobby or a job?

openasocket 2y ago

I think it’s shorter than you would imagine. I recall an episode of the podcast Arms Control Wonk talking about the nukes in possession of Ukraine during the collapse of the Soviet Union. Professor Lewis stated that those warheads likely had a service life of 5-10 years. But that may be specific to those Soviet warheads, and I think that different components need to be replaced at different intervals.

jmyeet 2y ago

So this varies depending on what kind of nuclear weapon is and the delivery system. The major deterrant is the LGM-30G Minuteman III [1]. Most of our rockets use liquid propellants. Since the alert window is under 10 minutes, you can't keep a liquid-fuelled rocket permanently fueled so the Minuteman was developed as a solid rocket fuel booster. There's a whole team responsible for maintaining the boosters and warheads of this first line of defense [2]. But there are a variety of other systems. Some dropped by strategic bombers, others on mobile launchers, shorter range missiles deployed in Europe (eg MRBMs in Turkey), nuclear weapons deployed on submarines and so on. Also you have a mix of types. AFAIK the US was moved away from highly-enriched uranium weapons in favor of plutonium. Or at least, HEU reactors have shut down. Maybe there's a sufficient stockpile? Also, a lot of these weapons will be thernonuclear so you have to worry about the production and storage of tritium. IIRC a lot of tritium is a byproduct of plutonium production. Maintaining a significant nuclear arsenal is actually really complex and expensive. [1]: https://en.wikipedia.org/wiki/LGM-30_Minuteman https://en.wikipedia.org/wiki/LGM-30_Minuteman [2]: https://minutemanmissile.com/missilemaintenance.html https://minutemanmissile.com/missilemaintenance.html

lmm 2y ago
> Since the alert window is under 10 minutes, you can't keep a liquid-fuelled rocket permanently fueled so the Minuteman was developed as a solid rocket fuel booster. Huh? The Titan II was developed to do precisely that and worked that way for decades, they were liquid-fuelled and kept fuelled in their silos.
- openasocket 2y ago
  Liquid propellants are generally less stable than solid fuel. I had read in multiple places (from reputable sources) that you generally couldn’t keep liquid missiles permanently fueled like that. The propellants are extremely corrosive and dangerous. But you are right that the Titan II is liquid fueled and was kept permanently fueled in the silo. I’m not entirely sure how to resolve those two facts. The Wikipedia page about the Titan II does mention multiple accidents and fatalities related to propellant leaks, so I’m guessing that they were just more risky to operate?

hollerith 2y ago

>I wonder how long a nuke in storage lasts Russia's nuclear stockpile -- at least the strategic warheads -- have all been built anew since the end of the Cold War. The US is also modernizing its stockpile in the same way, but it has not finished yet. "built anew": made with all new components except that the fissile material is recycled from an old Cold-War-era warhead. (They probably re-cast and re-machine the fissile material.) The reader might be asking, How can Russia, a poor country, afford that? Well, nukes aren't that expensive once you have the fissile material and the design and manufacturing expertise and infrastructure. The pay for the soldiers to guard the nukes and constantly be on the ready to launch them is more expensive, according to one report I saw recently (and Russia has low personnel costs).