30 ms·

One does not simply destroy a nuclear weapon

168 points by loteck 4y ago

loteck 4y ago
The author of the post is replying to an NYT article [0] complaining that the US doesn't actually destroy nukes, but rather aims to recycle materials and so stores those materials in the meantime while awaiting need for those materials. This makes it seem like maybe the US is just being opportunisitic and not actually disarming. Exceprt from the blog: Second, it's extremely difficult to destroy plutonium effectively (some weapons are built out of highly enriched uranium and that can just be diluted in U-238 and used for reactors). Obviously, you can melt it down, but that just leaves you with a chunk of subcritical plutonium which someone can re-form into a new weapon. The plutonium is highly toxic, so you can't just grind it up and scatter it around without causing huge environmental impacts (watch Chernobyl if you want to get a sense of what I'm talking about here). You can't burn it because then you're going to have oxidized plutonium in the air, which you don't want people inhaling, and while you can of course use chemicals to dissolve it, vitrify it, etc. you're still left with an equivalent amount of plutonium, just bonded to some other stuff, and so it's just a matter of (potentially highly unpleasant) chemistry to get it back out again. In other words, it's precisely the properties of plutonium that make it attractive to build nuclear weapons out of that make it so hard to dispose of. It's also very difficult to store because while an individual weapon may not be a critical mass, if you have tens or hundreds of weapons you have to worry about them getting close enough to worry about accidentally assembling a critical mass just from proximity, which, would of course, be bad. [0] https://archive.ph/QCaov https://archive.ph/QCaov
- xxpor 4y ago
  Now obviously this would cost a shitload of cash, but could you dispose of it by building a reactor? Said reactor would consume it as the fuel, and so you'd end up with fission products instead of plutonium. The costs, security, and the fact that reactors don't use up 100% of their fuel would of course be an issue...
  - ekr____ 4y ago
    OP here. Yes, this seems to be the best available approach. You apparently can burn it in regular reactors if you mix it with uranium in what's called "mixed oxide fuel" (MOX). However, there are a bunch of logistical hiccups that make all of this a giant pain.
    - philipkglass 4y ago
      In 2007 the United States started building a MOX facility at Savannah River for turning the old weapons plutonium into power reactor fuel. Its cost and time to completion ballooned far beyond original estimates and it was ultimately canceled. https://en.wikipedia.org/wiki/Savannah_River_Site#MOX_Fuel_Fabrication_Facility https://en.wikipedia.org/wiki/Savannah_River_Site#MOX_Fuel_F... "Cost estimate for MOX facility at Savannah River Site swells to $47.5 billion" https://www.augustachronicle.com/story/news/2015/04/22/cost-estimate-mox-facility-savannah-river-site-swells-475-billion/14371088007/ https://www.augustachronicle.com/story/news/2015/04/22/cost-... "US MOX facility contract terminated" https://world-nuclear-news.org/Articles/US-MOX-facility-contract-terminated https://world-nuclear-news.org/Articles/US-MOX-facility-cont...
    - PaulHoule 4y ago
      The US was planning to burn nuclear weapons plutonium in the Palo Verde plant in Arizona which are a European design designed to use MOX fuel from the very beginning. The hang up is that they were unable to build a MOX fabrication facility in the US even with the help of the French, who have run a successful MOX plant. I haven't seen a detailed explanation of what exactly went wrong, but it seems challenging to build a MOX facility to operate under US worker safety regulation. The trouble is that quality MOX fuel is made with a high energy ball mill that alloys uranium and plutonium oxides by making plutonium particles that are potentially deadly if you inhale them.
      - mrguyorama 4y ago
        Aren't you suggesting that the french have more lax worker protections than the US? I would be very skeptical of that claim. Now, maybe it was """hard""" (expensive) to properly protect your workers and so it didn't make business sense, and that for some reason is enough to kill most good things in the US
- implements 4y ago
  > It's also very difficult to store because while an individual weapon may not be a critical mass, if you have tens or hundreds of weapons you have to worry about them getting close enough to worry about accidentally assembling a critical mass just from proximity, which, would of course, be bad. Plutonium is an alpha emitter, and I believe the pits are plutonium alloyed with gallium and plated with gold to manage that and reduce chemical interactions with their immediate environment - there’s no “critical mass” storage problem, I think. [https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Material_considerations https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Material_...]
  - smaddox 4y ago
    Plutonium is definitely able to go critical: https://en.m.wikipedia.org/wiki/Demon_core https://en.m.wikipedia.org/wiki/Demon_core A plutonium sphere of roughly 10 kg is sufficient.
    - SlickNixon 4y ago
      I believe the original question was whether storage of multiple weapons in the same vicinity could result in accidental assembly of a critical mass, which appears to be something the author of the original blog came up with on their own.
      - ttyprintk 4y ago
        I think modern US designs are fusion boosted, making them immune to predetonation. Older experiments are increasingly dangerous, especially high-yield uranium guns.
        SlickNixon 4y ago
        Fission, boosted, or fusion all start with a fission bomb with a possibility to fizzle.
        4y ago
Victerius 4y ago
This raises a tricky question: Should the United States open or reopen a production line for nuclear weapons in order to avoid losing their manufacturing know-how, the way we do with M1A2 Abrams tanks? The United States once produced thousands of tanks per year. Today, there is only one tank plant left open in the nation, the Lima Army Tank Plant. For years, US Army leaders have asked Congress to stop purchasing new tanks because they didn't need them, but Congress kept ordering the Department of Defense to buy tanks anyway. They did this for two reasons. First, because the tank plant is a source of jobs in Ohio. Second, because tanks, especially modern, 21st century tanks, are specialized tools, and we wouldn't want to forget how to build them. An argument is made than it is cheaper to keep producing tanks that are not needed than it would be to restart a tank production line if one didn't exist. The argument is sensible and most likely true. After the US Air Force ordered an early end to the production of the F-22 Raptor in the early 2010s, the production line was dismantled. A report in the last few years estimated the cost to restart the production line in the billions, if not the low tens of billions. So, back to nuclear weapons. The United States manufactured tens of thousands of nuclear weapons during the Cold War. Most of these weapons have been decommissioned and the production lines have been shut down. The United States no longer manufactures nuclear weapons. Now, the incoming Ground Based Strategic Deterrent will be built by Northrop Grumman in the next few years to start replacing the aging Minuteman III ICBMs, but the warheads and the nuclear cores will be recycled from existing ICBMs. Which raises a question: How would the United States replenish its nuclear weapons if the need arose? For example, after a nuclear war, where the US lost or expended 80% of its arsenal? The question of what to do after a nuclear war may sound absurd to some, but it's a worthwhile and interesting one. More on point, what if the nuclear cores degrade to a point where they may no longer work? This is essentially what the Department of Energy's Nuclear Stewardship Program is for. It's a program that costs billions of dollars a year and uses supercomputers to model the slow degradation of the nuclear cores in the stockpile. But here's where it gets trickier. The New START treaty will expire in 2026. If it is not extended or replaced by a new treaty, there will be nothing stopping Russia from expanding its nuclear arsenal. China is also expanding its nuclear arsenal as we speak. Last week's report by the Department of Defense claims that China will have 1,500 nuclear weapons within a decade or so. China is building new nuclear weapons. The United States is not. And China is not bound by any arms control treaty. Now, the US also happens to have about 1,400-1,500 nuclear weapons deployed, plus a few thousand more in storage, disassembled. But what if China decides at some point to push past 1,500? To 2,000? 5,000? A country with 5,000 nuclear weapons could conduct a first strike against a country with 1,500 nuclear weapons, on a 2:1 ratio, and still have 2,000 nukes in reserve for further strikes. This is why the nuclear arms race happened between the US and the Soviet Union in the first place. Any disparity in the deployed arsenals gives the side with more the advantage. So if China ever decides to expand beyond 1,500, the strategically sound move for the US would be to start building more, to match the Chinese production. It would be tragic, but it's not impossible. But the US no longer manufactures nukes, so the old production lines would need to be reopened.
AtlasBarfed 4y ago
Well if the US government ran a LFTR / MSR they'd have both power for the facility and something to process a lot of the isotopes and a means for extraction. The core contention of the article is that plutonium disposal is an issue. Not in an MSR! (at least from my reading). I can see how solid fuel rods are precisely designed in old crappy fuel rod designs, since you need to design the rods to avoid them melting down. MSRs are meltdown proof, owing to the fluid nature of the fuel. If the fuel is overheating/overfissioning, then a "plug" that is artificially cooled will melt, and the fluid pours into a shallow pool. Since the shallow pool distributes the fissile material in a way that stops the chain reaction (since effectively a volume is reduced to a sheet, so all the neutrons in the vast majority of directions don't run into another fissionable/fissile nucleus, the reaction stops) Aside from the plutonium, IIRC molten salt reactors can "burn" a lot of "waste" isotopes since if it isn't fissile, let it hang around in the salt and a couple absorbed neutrons will make it something that can. The fission products are in a liquid, so the fluid can be chemically processed more easily to extract products. Yeah, there's a LOT of handwaving there, but fundamentally if you have a breeder reactor you can "process" waste into a usable form. The best thing about MSRs is that they scale to smaller sizes: the ORNL research reactor was closet-sized. A general MSR for fission product processing would have a lot more stuff for processing the salt for waste, yeah. As for replacement parts and the associated dangers for weapons construction, that's not really a nuclear issue once the nuclear material is separated. The inherent chemical toxicity of all this is a problem, but fundamentally what you are doing is containing the salts and processing them. Toxic stuff will eventually get transmuted to something else, so you just need to keep the core thorium -> uranium cycle going and "work on" all the rest of it to get it to a usable or more stable element. Yeah it's expensive, but TFA mentions billions for disposal/processing. Well, we could have had a usable MSR design and tons of knowhow to go with a good disposal method.
Havoc 4y ago
There is a pic somewhere showing south africa destroying theirs literally with angle grinders. Seems to have vanished from the internet though. Weird
- philipkglass 4y ago
  South Africa's weapons were made with enriched uranium [1]. Blending highly enriched uranium into power reactor fuel is relatively straightforward. The weapons discussed in this article are made with plutonium. There are a few facilities in the world for blending plutonium with uranium for power reactor fuel, but none that are designed to handle weapons grade plutonium. The US tried to build such a facility but it went badly over budget and over schedule and was cancelled: https://news.ycombinator.com/item?id=33868375 https://news.ycombinator.com/item?id=33868375 [1] https://en.wikipedia.org/wiki/South_Africa_and_weapons_of_mass_destruction#Nuclear_weapons https://en.wikipedia.org/wiki/South_Africa_and_weapons_of_ma...
acidburnNSA 4y ago
I can't believe this doesn't mention Megatons to Megawatts!? [1] For 20 years between 1993 and 2013, fully 10% of all US electricity came directly from dismantled ex-soviet nuclear weapons. We bought downblended highly-enriched uranium from the warheads and put it in our peaceful nuclear reactors. The bombs that were once aimed at cities then powered them. This was a beautiful and true destruction of nuclear weapons. Same can be done with plutonium using MOX fuel (as briefly mentioned at the end of the post). [1] https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program
- hn_throwaway_99 4y ago
  Thanks very much for posting this. I never knew about it, and always great to see a well-executed, purposeful government program that pretty much accomplished all of its goals.
- Joel_Mckay 4y ago
- godelski 4y ago
  For added context, this program led to the destruction of (effectively) over 20k soviet warheads. It is BY FAR the most successful deproliferation program.
  - sandworm101 4y ago
    For greater context, Russia and America maintain their nukes very differently. The US DOE studies them and works hard at maintaining existing stocks without building many new warheads. Russia does it differently. Their nukes have a finite lifespan. Once past, they are torn down, fuel reprocessed, and rebuilt from scratch. So pulling "20k" nukes out of the Russian system had a very different impact than pulling 20k would have from the US system. https://en.wikipedia.org/wiki/Mayak https://en.wikipedia.org/wiki/Mayak
    - sokoloff 4y ago
Joel_Mckay 4y ago
It literally takes 2 minutes to look up Plutonium disposition in CANDU reactors. The US has done a lot of messed up things, but is not going to risk global escalation over silly paranoia. If clowns are going to create defamatory mythologies about people, than at least don't use easily disproved FUD.
kennend3 4y ago
I"'m really shocked it doesn't mention CANDU's plutonium destruction. https://publications.gc.ca/Collection-R/LoPBdP/BP/bp461-e.htm https://publications.gc.ca/Collection-R/LoPBdP/BP/bp461-e.ht... "The Canadian CANDU reactors appear to be well suited to MOX fuel; they would not require physical modification and MOX fuel could be burned within existing operating and licensing envelopes. Furthermore, it is anticipated that existing safety standards governing the exposure of workers to radiation could be met or exceeded. The most significant change would be the implementation of enhanced security for the storage of new fuel prior to loading it in the reactors."
- HyperSane 4y ago
  It is strange how much the unique capabilities of CANDU reactors are ignored. It can run on unenriched uranium.
  - selectodude 4y ago
    Heavy water is really, really expensive.
    - MichaelZuo 4y ago
      Do you have some numbers? Is it 100x the cost per litre, 1000x, 10000x ?
      - 9wzYQbTYsAIc 4y ago
        According to Wikipedia, one liter goes for 2.23 USD [1]. [1] https://en.m.wikipedia.org/wiki/Prices_of_chemical_elements https://en.m.wikipedia.org/wiki/Prices_of_chemical_elements
        kennend3 4y ago
        This might make sense. I responded to this question as well and it seems the plant near me took $1.5 billion for the heavy water. After a bit of digging, it turns out it has approx. 500 tons of Heavy water.
craig_s_bell 4y ago
Good piece. IMHO the introductory narrative might be slightly enhanced by briefly pointing out that synthesis of plutonium was not achieved until several years after Szilard's brainstorm. Something like, "Researchers predicted that Pu would offer such-and-so advantages; however, nobody had quite yet come up with the recipe." In other words: As described with the high-level bomb design, every material and component therein was concurrently being developed, improvised or straight-up invented to meet existing theory. Thank you for recommending Rhodes' books; they are excellent. I may be alone in this; however I wish he had split 'Dark Sun' into two distinct volumes: One about the development of thermonuclear technology; and another for all of the spy stuff.
Finnucane 4y ago
Plutonium pits can be stored and reused, but not forever. Eventually enough decay products build up to make them unreliable. It's a big problem for long-term maintenance.
- rootusrootus 4y ago
  Relative to human timespans, the half life of plutonium is still pretty long. How long would it take to build up enough decay products to matter?
  - Finnucane 4y ago
    A few decades. Those pits are supposed to be pretty pure plutonium. Though it is something like the 'sell by' date on your milk. You open it up and think, is it really gone bad?
    - Xymist 4y ago
      And if you die three weeks later, it was still OK!
stackedinserter 4y ago
> the FAS report I linked above is from 1993 and states that "There is almost 1000 MT of reactor Pu (R-Pu) in existence now, with the amount growing by about 100 MT per year." Why couldn't we find a few kg for NASA missions? IIRC for Juno mission the DoE said "plutonium is out of stock for now, come later", so they had to use these oversized solar panels.
- philipkglass 4y ago
  Those deep space missions use plutonium 238 to power radioisotope thermoelectric generators: https://en.wikipedia.org/wiki/Plutonium-238#Use_in_radioisotope_thermoelectric_generators https://en.wikipedia.org/wiki/Plutonium-238#Use_in_radioisot... Surplus weapons plutonium is plutonium 239: https://en.wikipedia.org/wiki/Plutonium-239 https://en.wikipedia.org/wiki/Plutonium-239 Since plutonium 239 decays 275 times slower than plutonium 238, it also generates 275 times less decay heat and is therefore not useful in RTGs.
- avar 4y ago
  > Why couldn't we find a few kg for NASA missions? It's not a technical problem, but a bureaucratic dispute. NASA has been getting the Pu essentially for free, but the DoD/AEC made it as a byproduct. Now they don't anymore, and would like NASA's budget to pay for its manufacturing. NASA has decided it's not worth the money, and as a result is only using Pu power for missions that really need it, such as the large Mars rovers.
  - stackedinserter 4y ago
    Didn't know it, thanks!
cryptonector 4y ago
> The fusion component also seems to involve some isotopes of hydrogen (tritium and deuterium), so it would be modestly helpful to have that but my understanding is that it's not that hard to get your hands on these isotopes. Tritium is the most expensive thing on the planet that any of us can buy, by weight. Only exotic matter (non-naturally occurring elements, anti-matter) is more expensive, and that you basically can't buy. Tritium is not easy to make or get. And it has a half-life of 12 years. Deuterium can't be used instead of tritium.
- chasil 4y ago
  ...and you can buy a keychain with some of it. Don't break it. If you break it, don't breathe it. https://www.theregister.com/2015/03/18/atomic_keyring_brightness/ https://www.theregister.com/2015/03/18/atomic_keyring_bright...
  - 762236 4y ago
    That's wild that people would engineer something so dangerous if broken, particularly if the people using it are unaware that it contains tritium.
    - NavinF 4y ago
      That's because it's not particularly dangerous unless you grind it up into powder and snort it. Tritium handgun sights are fairly common. Also see polonium from Amazon: https://www.youtube.com/watch?v=ZBHIp967TD8 https://www.youtube.com/watch?v=ZBHIp967TD8 Most discussions about radiation are pure FUD unless they come from someone that works with this stuff every day.
- somat 4y ago
  The rest of that "fun fact"(tm) usually goes There are a number of things more expensive than tritium, for example: I think plutonium is more expensive than tritium. but you can't buy plutonium.
  - 4y ago
chasd00 4y ago
The easiest thing to do would probably be to deform the pit so it can't be used in a warhead without re-processing. Then store them in a box using the same policy/procedures as weapon storage. They don't take up a lot of space and it's not like they're being manufactured like crazy. Wikipedia says they're about 10cm in diameter which sounds about right, i thought they were around the size of a softball. https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Pit_sharing_between_weapons https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Pit_shari...
- no-dr-onboard 4y ago
  You wouldn't even have to do that. Command disablement systems (CDS) were purpose built for this.
moloch-hai 4y ago
The tone of this article resembles that in http://cantrip.org/bomb.html http://cantrip.org/bomb.html , by the brilliant Mark O'Donnell: "matter can be neither created nor destroyed, though it can get very discouraged." Also: "A little stray grime or margarine in your hairs-breadth mechanisms and you may find yourself festooning several square miles of nearby woodland."
deleted 4y ago
[deleted]
GartzenDeHaes 4y ago
This is a little more complicated than what you can learn from wikipedia. Many thousands of US and Soviet nuclear weapons were demilitarized under the START treaties, mostly at the PANTEX plant in Texas. Demilitarized means that they were disassembled and/or damaged in such a way that they cannot be used for military purposes without extensive reprocessing or re-manufacturing. The demilled components are still radioactive, toxic, and/or classified, so they have to be securely stored somewhere. The parts from old weapons that have completely or partially been dismantled are also held in storage. Some of the non-fissionable materials can be recycled, but the uranium would require reprocessing and re-manufacturing to be used in a weapon. It may be possible to reassemble old weapons from these components, but for what purpose? These weapons were retired for practical reasons such as being replaced by newer, better, and safer weapons (from the point of view of the DOE and DOD). There are also complete weapons in storage that are no longer in active service. Inactive weapons are unmaintained, but could be returned to service with field level maintenance. Some of these are kept to support war plans for contingencies or capabilities that are not a current priority. For the majority though, there's a significant cost to dismantle them and no pressing need to do so.
birdyrooster 4y ago
I don't think there is a better use of Mordor meme
- quickthrower2 4y ago
  “… confiscate bitcoin” was the first one I saw and is my favourite. Although it is not really true.
User23 4y ago
> “It’s important to keep these parts around,” said Franklin C. Miller, a nuclear expert who held federal posts for three decades before leaving government service in 2005. “If we had the manufacturing complex we once did, we wouldn’t have to rely on the old parts.” He added that other nuclear powers can and do make new atomic parts. This is depressing. It’s much like the F-22, we’ve lost the capability to make those too. It’s remarkable how rapidly the USA has declined in the past couple decades. Pretty much the only thing we have going for us is a stranglehold on international payments, and that won’t last.
w10-1 4y ago
Whether we can reprocess the fuel I think misses a larger point. We disassemble and save parts because we don't - can't - build more. I'm told by Livermore nuclear weapons engineers (admittedly anecdotal hearsay) that it's crazy not to test these weapons. They degrade and fail in ways and at speeds not unanticipated, and computer modeling could not replace actual testing (at least back in ~2000-2005). So we built a bunch in a rush, found they might last 3 years or 7 years or some other random number, and now... we hold on to them and hope they work, or hope they'll work with scavenged replacement parts. I'm sure a few carefully curated ones work, but the failure rate could be closer to 90% than 10%. Perhaps our negligence will save us all.
- actionfromafar 4y ago
  Perhaps our negligence will save enough many to keep civilization going after most large cities are burnt husks.
trenchgun 4y ago
Was this whole article generated by GPT-3?

168 points by loteck 4y ago

The author of the post is replying to an NYT article [0] complaining that the US doesn't actually destroy nukes, but rather aims to recycle materials and so stores those materials in the meantime while awaiting need for those materials. This makes it seem like maybe the US is just being opportunisitic and not actually disarming. Exceprt from the blog: Second, it's extremely difficult to destroy plutonium effectively (some weapons are built out of highly enriched uranium and that can just be diluted in U-238 and used for reactors). Obviously, you can melt it down, but that just leaves you with a chunk of subcritical plutonium which someone can re-form into a new weapon. The plutonium is highly toxic, so you can't just grind it up and scatter it around without causing huge environmental impacts (watch Chernobyl if you want to get a sense of what I'm talking about here). You can't burn it because then you're going to have oxidized plutonium in the air, which you don't want people inhaling, and while you can of course use chemicals to dissolve it, vitrify it, etc. you're still left with an equivalent amount of plutonium, just bonded to some other stuff, and so it's just a matter of (potentially highly unpleasant) chemistry to get it back out again. In other words, it's precisely the properties of plutonium that make it attractive to build nuclear weapons out of that make it so hard to dispose of. It's also very difficult to store because while an individual weapon may not be a critical mass, if you have tens or hundreds of weapons you have to worry about them getting close enough to worry about accidentally assembling a critical mass just from proximity, which, would of course, be bad. [0] https://archive.ph/QCaov https://archive.ph/QCaov

xxpor 4y ago
Now obviously this would cost a shitload of cash, but could you dispose of it by building a reactor? Said reactor would consume it as the fuel, and so you'd end up with fission products instead of plutonium. The costs, security, and the fact that reactors don't use up 100% of their fuel would of course be an issue...
- ekr____ 4y ago
  OP here. Yes, this seems to be the best available approach. You apparently can burn it in regular reactors if you mix it with uranium in what's called "mixed oxide fuel" (MOX). However, there are a bunch of logistical hiccups that make all of this a giant pain.
  - philipkglass 4y ago
    In 2007 the United States started building a MOX facility at Savannah River for turning the old weapons plutonium into power reactor fuel. Its cost and time to completion ballooned far beyond original estimates and it was ultimately canceled. https://en.wikipedia.org/wiki/Savannah_River_Site#MOX_Fuel_Fabrication_Facility https://en.wikipedia.org/wiki/Savannah_River_Site#MOX_Fuel_F... "Cost estimate for MOX facility at Savannah River Site swells to $47.5 billion" https://www.augustachronicle.com/story/news/2015/04/22/cost-estimate-mox-facility-savannah-river-site-swells-475-billion/14371088007/ https://www.augustachronicle.com/story/news/2015/04/22/cost-... "US MOX facility contract terminated" https://world-nuclear-news.org/Articles/US-MOX-facility-contract-terminated https://world-nuclear-news.org/Articles/US-MOX-facility-cont...
  - PaulHoule 4y ago
    The US was planning to burn nuclear weapons plutonium in the Palo Verde plant in Arizona which are a European design designed to use MOX fuel from the very beginning. The hang up is that they were unable to build a MOX fabrication facility in the US even with the help of the French, who have run a successful MOX plant. I haven't seen a detailed explanation of what exactly went wrong, but it seems challenging to build a MOX facility to operate under US worker safety regulation. The trouble is that quality MOX fuel is made with a high energy ball mill that alloys uranium and plutonium oxides by making plutonium particles that are potentially deadly if you inhale them.
    - mrguyorama 4y ago
      Aren't you suggesting that the french have more lax worker protections than the US? I would be very skeptical of that claim. Now, maybe it was """hard""" (expensive) to properly protect your workers and so it didn't make business sense, and that for some reason is enough to kill most good things in the US
implements 4y ago
> It's also very difficult to store because while an individual weapon may not be a critical mass, if you have tens or hundreds of weapons you have to worry about them getting close enough to worry about accidentally assembling a critical mass just from proximity, which, would of course, be bad. Plutonium is an alpha emitter, and I believe the pits are plutonium alloyed with gallium and plated with gold to manage that and reduce chemical interactions with their immediate environment - there’s no “critical mass” storage problem, I think. [https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Material_considerations https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Material_...]
- smaddox 4y ago
  Plutonium is definitely able to go critical: https://en.m.wikipedia.org/wiki/Demon_core https://en.m.wikipedia.org/wiki/Demon_core A plutonium sphere of roughly 10 kg is sufficient.
  - SlickNixon 4y ago
    I believe the original question was whether storage of multiple weapons in the same vicinity could result in accidental assembly of a critical mass, which appears to be something the author of the original blog came up with on their own.
    - ttyprintk 4y ago
      I think modern US designs are fusion boosted, making them immune to predetonation. Older experiments are increasingly dangerous, especially high-yield uranium guns.
      - SlickNixon 4y ago
        Fission, boosted, or fusion all start with a fission bomb with a possibility to fizzle.
        4y ago

Victerius 4y ago

This raises a tricky question: Should the United States open or reopen a production line for nuclear weapons in order to avoid losing their manufacturing know-how, the way we do with M1A2 Abrams tanks? The United States once produced thousands of tanks per year. Today, there is only one tank plant left open in the nation, the Lima Army Tank Plant. For years, US Army leaders have asked Congress to stop purchasing new tanks because they didn't need them, but Congress kept ordering the Department of Defense to buy tanks anyway. They did this for two reasons. First, because the tank plant is a source of jobs in Ohio. Second, because tanks, especially modern, 21st century tanks, are specialized tools, and we wouldn't want to forget how to build them. An argument is made than it is cheaper to keep producing tanks that are not needed than it would be to restart a tank production line if one didn't exist. The argument is sensible and most likely true. After the US Air Force ordered an early end to the production of the F-22 Raptor in the early 2010s, the production line was dismantled. A report in the last few years estimated the cost to restart the production line in the billions, if not the low tens of billions. So, back to nuclear weapons. The United States manufactured tens of thousands of nuclear weapons during the Cold War. Most of these weapons have been decommissioned and the production lines have been shut down. The United States no longer manufactures nuclear weapons. Now, the incoming Ground Based Strategic Deterrent will be built by Northrop Grumman in the next few years to start replacing the aging Minuteman III ICBMs, but the warheads and the nuclear cores will be recycled from existing ICBMs. Which raises a question: How would the United States replenish its nuclear weapons if the need arose? For example, after a nuclear war, where the US lost or expended 80% of its arsenal? The question of what to do after a nuclear war may sound absurd to some, but it's a worthwhile and interesting one. More on point, what if the nuclear cores degrade to a point where they may no longer work? This is essentially what the Department of Energy's Nuclear Stewardship Program is for. It's a program that costs billions of dollars a year and uses supercomputers to model the slow degradation of the nuclear cores in the stockpile. But here's where it gets trickier. The New START treaty will expire in 2026. If it is not extended or replaced by a new treaty, there will be nothing stopping Russia from expanding its nuclear arsenal. China is also expanding its nuclear arsenal as we speak. Last week's report by the Department of Defense claims that China will have 1,500 nuclear weapons within a decade or so. China is building new nuclear weapons. The United States is not. And China is not bound by any arms control treaty. Now, the US also happens to have about 1,400-1,500 nuclear weapons deployed, plus a few thousand more in storage, disassembled. But what if China decides at some point to push past 1,500? To 2,000? 5,000? A country with 5,000 nuclear weapons could conduct a first strike against a country with 1,500 nuclear weapons, on a 2:1 ratio, and still have 2,000 nukes in reserve for further strikes. This is why the nuclear arms race happened between the US and the Soviet Union in the first place. Any disparity in the deployed arsenals gives the side with more the advantage. So if China ever decides to expand beyond 1,500, the strategically sound move for the US would be to start building more, to match the Chinese production. It would be tragic, but it's not impossible. But the US no longer manufactures nukes, so the old production lines would need to be reopened.

AtlasBarfed 4y ago

Well if the US government ran a LFTR / MSR they'd have both power for the facility and something to process a lot of the isotopes and a means for extraction. The core contention of the article is that plutonium disposal is an issue. Not in an MSR! (at least from my reading). I can see how solid fuel rods are precisely designed in old crappy fuel rod designs, since you need to design the rods to avoid them melting down. MSRs are meltdown proof, owing to the fluid nature of the fuel. If the fuel is overheating/overfissioning, then a "plug" that is artificially cooled will melt, and the fluid pours into a shallow pool. Since the shallow pool distributes the fissile material in a way that stops the chain reaction (since effectively a volume is reduced to a sheet, so all the neutrons in the vast majority of directions don't run into another fissionable/fissile nucleus, the reaction stops) Aside from the plutonium, IIRC molten salt reactors can "burn" a lot of "waste" isotopes since if it isn't fissile, let it hang around in the salt and a couple absorbed neutrons will make it something that can. The fission products are in a liquid, so the fluid can be chemically processed more easily to extract products. Yeah, there's a LOT of handwaving there, but fundamentally if you have a breeder reactor you can "process" waste into a usable form. The best thing about MSRs is that they scale to smaller sizes: the ORNL research reactor was closet-sized. A general MSR for fission product processing would have a lot more stuff for processing the salt for waste, yeah. As for replacement parts and the associated dangers for weapons construction, that's not really a nuclear issue once the nuclear material is separated. The inherent chemical toxicity of all this is a problem, but fundamentally what you are doing is containing the salts and processing them. Toxic stuff will eventually get transmuted to something else, so you just need to keep the core thorium -> uranium cycle going and "work on" all the rest of it to get it to a usable or more stable element. Yeah it's expensive, but TFA mentions billions for disposal/processing. Well, we could have had a usable MSR design and tons of knowhow to go with a good disposal method.

Havoc 4y ago

There is a pic somewhere showing south africa destroying theirs literally with angle grinders. Seems to have vanished from the internet though. Weird

philipkglass 4y ago
South Africa's weapons were made with enriched uranium [1]. Blending highly enriched uranium into power reactor fuel is relatively straightforward. The weapons discussed in this article are made with plutonium. There are a few facilities in the world for blending plutonium with uranium for power reactor fuel, but none that are designed to handle weapons grade plutonium. The US tried to build such a facility but it went badly over budget and over schedule and was cancelled: https://news.ycombinator.com/item?id=33868375 https://news.ycombinator.com/item?id=33868375 [1] https://en.wikipedia.org/wiki/South_Africa_and_weapons_of_mass_destruction#Nuclear_weapons https://en.wikipedia.org/wiki/South_Africa_and_weapons_of_ma...

acidburnNSA 4y ago

I can't believe this doesn't mention Megatons to Megawatts!? [1] For 20 years between 1993 and 2013, fully 10% of all US electricity came directly from dismantled ex-soviet nuclear weapons. We bought downblended highly-enriched uranium from the warheads and put it in our peaceful nuclear reactors. The bombs that were once aimed at cities then powered them. This was a beautiful and true destruction of nuclear weapons. Same can be done with plutonium using MOX fuel (as briefly mentioned at the end of the post). [1] https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program https://en.wikipedia.org/wiki/Megatons_to_Megawatts_Program

hn_throwaway_99 4y ago
Thanks very much for posting this. I never knew about it, and always great to see a well-executed, purposeful government program that pretty much accomplished all of its goals.
Joel_Mckay 4y ago
godelski 4y ago
For added context, this program led to the destruction of (effectively) over 20k soviet warheads. It is BY FAR the most successful deproliferation program.
- sandworm101 4y ago
  For greater context, Russia and America maintain their nukes very differently. The US DOE studies them and works hard at maintaining existing stocks without building many new warheads. Russia does it differently. Their nukes have a finite lifespan. Once past, they are torn down, fuel reprocessed, and rebuilt from scratch. So pulling "20k" nukes out of the Russian system had a very different impact than pulling 20k would have from the US system. https://en.wikipedia.org/wiki/Mayak https://en.wikipedia.org/wiki/Mayak
  - sokoloff 4y ago

Joel_Mckay 4y ago

It literally takes 2 minutes to look up Plutonium disposition in CANDU reactors. The US has done a lot of messed up things, but is not going to risk global escalation over silly paranoia. If clowns are going to create defamatory mythologies about people, than at least don't use easily disproved FUD.

kennend3 4y ago

I"'m really shocked it doesn't mention CANDU's plutonium destruction. https://publications.gc.ca/Collection-R/LoPBdP/BP/bp461-e.htm https://publications.gc.ca/Collection-R/LoPBdP/BP/bp461-e.ht... "The Canadian CANDU reactors appear to be well suited to MOX fuel; they would not require physical modification and MOX fuel could be burned within existing operating and licensing envelopes. Furthermore, it is anticipated that existing safety standards governing the exposure of workers to radiation could be met or exceeded. The most significant change would be the implementation of enhanced security for the storage of new fuel prior to loading it in the reactors."

HyperSane 4y ago
It is strange how much the unique capabilities of CANDU reactors are ignored. It can run on unenriched uranium.
- selectodude 4y ago
  Heavy water is really, really expensive.
  - MichaelZuo 4y ago
    Do you have some numbers? Is it 100x the cost per litre, 1000x, 10000x ?
    - 9wzYQbTYsAIc 4y ago
      According to Wikipedia, one liter goes for 2.23 USD [1]. [1] https://en.m.wikipedia.org/wiki/Prices_of_chemical_elements https://en.m.wikipedia.org/wiki/Prices_of_chemical_elements
      - kennend3 4y ago
        This might make sense. I responded to this question as well and it seems the plant near me took $1.5 billion for the heavy water. After a bit of digging, it turns out it has approx. 500 tons of Heavy water.

craig_s_bell 4y ago

Good piece. IMHO the introductory narrative might be slightly enhanced by briefly pointing out that synthesis of plutonium was not achieved until several years after Szilard's brainstorm. Something like, "Researchers predicted that Pu would offer such-and-so advantages; however, nobody had quite yet come up with the recipe." In other words: As described with the high-level bomb design, every material and component therein was concurrently being developed, improvised or straight-up invented to meet existing theory. Thank you for recommending Rhodes' books; they are excellent. I may be alone in this; however I wish he had split 'Dark Sun' into two distinct volumes: One about the development of thermonuclear technology; and another for all of the spy stuff.

Finnucane 4y ago

Plutonium pits can be stored and reused, but not forever. Eventually enough decay products build up to make them unreliable. It's a big problem for long-term maintenance.

rootusrootus 4y ago
Relative to human timespans, the half life of plutonium is still pretty long. How long would it take to build up enough decay products to matter?
- Finnucane 4y ago
  A few decades. Those pits are supposed to be pretty pure plutonium. Though it is something like the 'sell by' date on your milk. You open it up and think, is it really gone bad?
  - Xymist 4y ago
    And if you die three weeks later, it was still OK!

stackedinserter 4y ago

> the FAS report I linked above is from 1993 and states that "There is almost 1000 MT of reactor Pu (R-Pu) in existence now, with the amount growing by about 100 MT per year." Why couldn't we find a few kg for NASA missions? IIRC for Juno mission the DoE said "plutonium is out of stock for now, come later", so they had to use these oversized solar panels.

philipkglass 4y ago
Those deep space missions use plutonium 238 to power radioisotope thermoelectric generators: https://en.wikipedia.org/wiki/Plutonium-238#Use_in_radioisotope_thermoelectric_generators https://en.wikipedia.org/wiki/Plutonium-238#Use_in_radioisot... Surplus weapons plutonium is plutonium 239: https://en.wikipedia.org/wiki/Plutonium-239 https://en.wikipedia.org/wiki/Plutonium-239 Since plutonium 239 decays 275 times slower than plutonium 238, it also generates 275 times less decay heat and is therefore not useful in RTGs.
avar 4y ago
> Why couldn't we find a few kg for NASA missions? It's not a technical problem, but a bureaucratic dispute. NASA has been getting the Pu essentially for free, but the DoD/AEC made it as a byproduct. Now they don't anymore, and would like NASA's budget to pay for its manufacturing. NASA has decided it's not worth the money, and as a result is only using Pu power for missions that really need it, such as the large Mars rovers.
- stackedinserter 4y ago
  Didn't know it, thanks!

cryptonector 4y ago

> The fusion component also seems to involve some isotopes of hydrogen (tritium and deuterium), so it would be modestly helpful to have that but my understanding is that it's not that hard to get your hands on these isotopes. Tritium is the most expensive thing on the planet that any of us can buy, by weight. Only exotic matter (non-naturally occurring elements, anti-matter) is more expensive, and that you basically can't buy. Tritium is not easy to make or get. And it has a half-life of 12 years. Deuterium can't be used instead of tritium.

chasil 4y ago
...and you can buy a keychain with some of it. Don't break it. If you break it, don't breathe it. https://www.theregister.com/2015/03/18/atomic_keyring_brightness/ https://www.theregister.com/2015/03/18/atomic_keyring_bright...
- 762236 4y ago
  That's wild that people would engineer something so dangerous if broken, particularly if the people using it are unaware that it contains tritium.
  - NavinF 4y ago
    That's because it's not particularly dangerous unless you grind it up into powder and snort it. Tritium handgun sights are fairly common. Also see polonium from Amazon: https://www.youtube.com/watch?v=ZBHIp967TD8 https://www.youtube.com/watch?v=ZBHIp967TD8 Most discussions about radiation are pure FUD unless they come from someone that works with this stuff every day.
somat 4y ago
The rest of that "fun fact"(tm) usually goes There are a number of things more expensive than tritium, for example: I think plutonium is more expensive than tritium. but you can't buy plutonium.
- 4y ago

chasd00 4y ago

The easiest thing to do would probably be to deform the pit so it can't be used in a warhead without re-processing. Then store them in a box using the same policy/procedures as weapon storage. They don't take up a lot of space and it's not like they're being manufactured like crazy. Wikipedia says they're about 10cm in diameter which sounds about right, i thought they were around the size of a softball. https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Pit_sharing_between_weapons https://en.wikipedia.org/wiki/Pit_(nuclear_weapon)#Pit_shari...

no-dr-onboard 4y ago
You wouldn't even have to do that. Command disablement systems (CDS) were purpose built for this.

moloch-hai 4y ago

The tone of this article resembles that in http://cantrip.org/bomb.html http://cantrip.org/bomb.html , by the brilliant Mark O'Donnell: "matter can be neither created nor destroyed, though it can get very discouraged." Also: "A little stray grime or margarine in your hairs-breadth mechanisms and you may find yourself festooning several square miles of nearby woodland."

deleted 4y ago

[deleted]

GartzenDeHaes 4y ago

This is a little more complicated than what you can learn from wikipedia. Many thousands of US and Soviet nuclear weapons were demilitarized under the START treaties, mostly at the PANTEX plant in Texas. Demilitarized means that they were disassembled and/or damaged in such a way that they cannot be used for military purposes without extensive reprocessing or re-manufacturing. The demilled components are still radioactive, toxic, and/or classified, so they have to be securely stored somewhere. The parts from old weapons that have completely or partially been dismantled are also held in storage. Some of the non-fissionable materials can be recycled, but the uranium would require reprocessing and re-manufacturing to be used in a weapon. It may be possible to reassemble old weapons from these components, but for what purpose? These weapons were retired for practical reasons such as being replaced by newer, better, and safer weapons (from the point of view of the DOE and DOD). There are also complete weapons in storage that are no longer in active service. Inactive weapons are unmaintained, but could be returned to service with field level maintenance. Some of these are kept to support war plans for contingencies or capabilities that are not a current priority. For the majority though, there's a significant cost to dismantle them and no pressing need to do so.

birdyrooster 4y ago

I don't think there is a better use of Mordor meme

quickthrower2 4y ago
“… confiscate bitcoin” was the first one I saw and is my favourite. Although it is not really true.

User23 4y ago

> “It’s important to keep these parts around,” said Franklin C. Miller, a nuclear expert who held federal posts for three decades before leaving government service in 2005. “If we had the manufacturing complex we once did, we wouldn’t have to rely on the old parts.” He added that other nuclear powers can and do make new atomic parts. This is depressing. It’s much like the F-22, we’ve lost the capability to make those too. It’s remarkable how rapidly the USA has declined in the past couple decades. Pretty much the only thing we have going for us is a stranglehold on international payments, and that won’t last.

w10-1 4y ago

Whether we can reprocess the fuel I think misses a larger point. We disassemble and save parts because we don't - can't - build more. I'm told by Livermore nuclear weapons engineers (admittedly anecdotal hearsay) that it's crazy not to test these weapons. They degrade and fail in ways and at speeds not unanticipated, and computer modeling could not replace actual testing (at least back in ~2000-2005). So we built a bunch in a rush, found they might last 3 years or 7 years or some other random number, and now... we hold on to them and hope they work, or hope they'll work with scavenged replacement parts. I'm sure a few carefully curated ones work, but the failure rate could be closer to 90% than 10%. Perhaps our negligence will save us all.

actionfromafar 4y ago
Perhaps our negligence will save enough many to keep civilization going after most large cities are burnt husks.

trenchgun 4y ago

Was this whole article generated by GPT-3?