# How many megatons of yield cold a sub/aircraft carrier nuclear reactor fuel be used to produce? **URL:** \ **Category:** Factual Questions\ **Created:** [July 23, 2019, 4:14pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503 "2019-07-23T16:14:37Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [July 24, 2019, 5:39pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/21 "2019-07-24T17:39:18Z")
> [@beowulff](#): > > That’s too much U-235 for one bomb - there’s no practical way to assemble that much mass from sub-to-super critical in a short enough time to avoid a fizzle. So, you would probably want to make 3-4 big bombs, each with 500KT or so yield. So, 1 submarine = 1.5-2megatons? How about the largest US aircraft carriers, how many kg of uranium do they have? Aren’t there nukes with more than 1megaton of yield? The B83 has 1.2MT so it must be possible to get more than 500KT. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [July 24, 2019, 5:48pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/22 "2019-07-24T17:48:00Z")
> [@MichaelEmouse](#): > > So, 1 submarine = 1.5-2megatons? > > How about the largest US aircraft carriers, how many kg of uranium do they have? > Aren’t there nukes with more than 1megaton of yield? The B83 has 1.2MT so it must be possible to get more than 500KT. As people keep saying, the yield of a Thermonuclear weapon has little to do with the amount of fissionable material. You only need a relatively small fission bomb to induce fusion and then fast-fission in the casing. So, with your 200KT of HEU, you could probably make many megatons of explosive power - if you had plenty of Lithium Deuteride. Look at the “dial-a-yield” weapons, like the [B83](https://en.wikipedia.org/wiki/B83_nuclear_bomb) you mentioned above. With no fusion boost, it yields in the low-kt range (just the yield of the primary). With full boost, you get 1.2MT. So, your 200KT of HEU might give you 20 or more bombs of this size. But, you still need plenty of fusion fuel. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [July 24, 2019, 5:59pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/23 "2019-07-24T17:59:33Z")
You wouldn’t make a fission-type weapon using several critical masses in order to construct a huge hydrogen bomb, though. You could use it as the primary in a staged thermonuclear device. I’m sure you could get some number between 10 and 20 cores out of it. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [July 24, 2019, 6:03pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/24 "2019-07-24T18:03:21Z")
> [@MichaelEmouse](#): > > Aren’t there nukes with more than 1megaton of yield? The B83 has 1.2MT so it must be possible to get more than 500KT. These are all thermonuclear weapons. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [July 24, 2019, 6:07pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/25 "2019-07-24T18:07:46Z")
> [@beowulff](#): > > As people keep saying, the yield of a Thermonuclear weapon has little to do with the amount of fissionable material. You only need a relatively small fission bomb to induce fusion and then fast-fission in the casing. So, with your 200KT of HEU, you could probably make many megatons of explosive power - if you had plenty of Lithium Deuteride. > > Look at the “dial-a-yield” weapons, like the [B83](https://en.wikipedia.org/wiki/B83_nuclear_bomb) you mentioned above. With no fusion boost, it yields in the low-kt range (just the yield of the primary). With full boost, you get 1.2MT. So, your 200KT of HEU might give you 20 or more bombs of this size. But, you still need plenty of fusion fuel. What material(s) are required for the fusion boost/fuel? How much fissionable material like uranium is there in a 1MT thermonuclear bomb? > [@DPRK](#): > > These are all thermonuclear weapons. Yep. And I’m asking what kind of boom you’d get if you used that much uranium in thermonuclear nukes, provided you had the other materials and components. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [July 24, 2019, 7:02pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/26 "2019-07-24T19:02:27Z")
> [@MichaelEmouse](#): > > What material(s) are required for the fusion boost/fuel? Uranium, plutonium, tritium, lithium deuteride… > [@](#): > > How much fissionable material like uranium is there in a 1MT thermonuclear bomb? Let’s say roughly 15 kg? You could make it smaller if you had weapons-grade plutonium. > [@](#): > > Yep. And I’m asking what kind of boom you’d get if you used that much uranium in thermonuclear nukes, provided you had the other materials and components. I’m still going with “unlimited”, barring any practical considerations like delivery mechanism or the fact that e.g. a 200 MT bomb is too big to be of military use. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [July 24, 2019, 7:46pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/27 "2019-07-24T19:46:39Z")
> [@DPRK](#): > > Uranium, plutonium, tritium, lithium deuteride… > > Let’s say roughly 15 kg? You could make it smaller if you had weapons-grade plutonium. > > I’m still going with “unlimited”, barring any practical considerations like delivery mechanism or the fact that e.g. a 200 MT bomb is too big to be of military use. Unlimited yield would require an unlimited number of successively larger (and presumably less reliable) stages though. The “cleanest” fusion bomb ever tested, the Russian “Tsar bomb”, is believed to have been a three stage (fission-fusion-fusion) device, with a fusion/total yield ratio of 97%. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 24, 2019, 7:59pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/28 "2019-07-24T19:59:10Z")
As others have said, you could use that much fissionable material to make a total of 10-20ish separate device, and each device could have pretty much whatever yield you wanted. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [July 24, 2019, 8:09pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/29 "2019-07-24T20:09:57Z")
> [@beowulff](#): > > As people keep saying, the yield of a Thermonuclear weapon has little to do with the amount of fissionable material. People keep saying this, but it’s wrong. Lithium deuteride isn’t difficult to make or obtain. Most of the yield of a thermonuclear weapon comes from fission. The fissile material is the limiting ingredient of explosive yield. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [July 24, 2019, 10:37pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/30 "2019-07-24T22:37:05Z")
> [@HMS\_Irruncible](#): > > People keep saying this, but it’s wrong. Lithium deuteride isn’t difficult to make or obtain. Most of the yield of a thermonuclear weapon comes from fission. The fissile material is the limiting ingredient of explosive yield. After uranium, would the second limiting ingredient be plutonium? Are there nuclear reactors that at least partially rely on plutonium? If most of the yield from a thermonuclear nuke comes from fission, why bother with the fusion? Why are nukes that use fusion so much more powerful than fission-only nukes? > [@DPRK](#): > > Let’s say roughly 15 kg? You could make it smaller if you had weapons-grade plutonium. Cite? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [July 24, 2019, 10:40pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/31 "2019-07-24T22:40:48Z")
> [@HMS\_Irruncible](#): > > People keep saying this, but it’s wrong. Lithium deuteride isn’t difficult to make or obtain. Most of the yield of a thermonuclear weapon comes from fission. The fissile material is the limiting ingredient of explosive yield. Untrue. Most of the yield comes from the fast-fission of the _fissionable_ casing. And, depleted Uranium is so cheap it’s used as ammunition. But, making a Thermonuclear bomb isn’t something that’s easy to do, no matter how much U-235 or PU-239 you have. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [July 24, 2019, 11:07pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/32 "2019-07-24T23:07:27Z")
> [@MichaelEmouse](#): > > Cite? [Nuclear Weapons FAQ](https://nuclearweaponarchive.org/Nwfaq/Nfaq4-2.html#Nfaq4.2), section 4.2. See also section 4.4. It is also explained why pure-fission weapons exceeding a few hundred megatons become increasingly impractical and unsafe. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [July 24, 2019, 11:19pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/33 "2019-07-24T23:19:36Z")
The timing and dispersal pattern of nuclear weapons is considerably more important in total destruction achieved. The bombing of Dresden provided proof of concept that accurately placed chemical bombs could initiate a firestorm far greater than the historic detonations of Thermonuclear weapons. In the decades since WWII the ability of at least three of the major powers to deliver nuclear blasts of two to thirty kilotons in physically, and temporally precise patterns to create kilometer wide self sustaining firestorms that would move through many kilometers as far fuel was available. Burning at those temperatures all organic material, as well as asphalt, and iron fall into the category fuel. By selecting near ground detonations, the amount of fallout can be increased to make wide areas downwind uninhabitable for decades, or centuries. Although the scientific and engineering capabilities to create such weapons are formidable, and expensive, they are not outside the range of capabilities of many nation states, and require minimal amounts of actual fissionable materials, if properly designed. Delivery systems are not limited to rockets, or aircraft. Tris * * * It’s at least as bad as you think. Probably worse. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [July 25, 2019, 12:02am UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/34 "2019-07-25T00:02:38Z")
Plutonium seems to have higher energy density than uranium, why is it not used more? In which situations would you use uranium and which would you use plutonium as far as power generation and nukes are concerned? Context: I’m trying to imagine a war between two different factions and trying to see what kind of trade-offs they would face in terms of generating power as on ships vs explosive yield. When a country decides to put out a nuclear submarine or aircraft carrier, what’s the opportunity cost in terms of megatons of explosive yield? ---
**Author:** ![Gray\_Ghost](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)\ **Post date:** [July 25, 2019, 5:26am UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/35 "2019-07-25T05:26:43Z")
> [@Chronos](#): > > I think that, even on a Navy ship, the fuel still isn’t enriched all the way to weapons-grade levels (though it’s more than for civilian reactors)… [Not true.](https://fas.org/irp/agency/dod/jason/leu-naval.pdf). Albeit I believe there are other things in the fuel that you’d want to remove before trying to make a bomb out of it. Even before initially loading the fuel rods. But if the chart at Table 1 at the .pdf is right, they run on 93-97% U235. So did the Soviets’. Which was one reason why things like Project Sapphire were so important. Imagine a bunch of naval reactor fuel, just sitting there in subcritical configurations, guarded by a padlock… A big question I had was , “How do they not form a supercritical configuration, under say battle damage?” ---
**Author:** ![Gray\_Ghost](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)\ **Post date:** [July 25, 2019, 5:30am UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/36 "2019-07-25T05:30:08Z")
[This paper](https://media.nti.org/pdfs/Replacing_HEU_in_Naval_Reactors_Report_FINAL.pdf) by NTI goes into a bit more detail about replacing HEU with lower enriched fuels for nuclear propulsion, and the tradeoffs therein. And now, back to lurking. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [July 25, 2019, 2:16pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/37 "2019-07-25T14:16:01Z")
> [@beowulff](#): > > Untrue. > Most of the yield comes from the fast-fission of the _fissionable_ casing. This is not different from what I said. The fissionable material is the limiting component. Not the hydrogen. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [July 25, 2019, 2:31pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/38 "2019-07-25T14:31:10Z")
> [@Chronos](#): > > That should actually be reiterated, that such weapons aren’t viable. They can be built, sure, but they don’t accomplish any useful mission: A small nuke blows up a city-sized target real good, and a large nuke blows up a city-sized target realer gooder. If you want to increase your actual useful firepower, then you need more bombs, not bigger ones, which means you need a critical mass of fissionable material for each one. Intensity is inversely proportional to the square of the distance. Relatively small increases in accuracy can have substantial increases in deadliness. For instance, the Chayanne Mountain Complex was designed to survive a 3000 kt warhead at 1 nautical mile or 1800 m distance (lets round off and call it 2000 m) 200 m is within the CEP of modern ICBMs. At that range, it could survive a burst of only about 30kt. Modern ICBM’s have multiple warheads of a few hundred KT each. Complex is well and truly fucked. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [July 25, 2019, 2:32pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/39 "2019-07-25T14:32:46Z")
> [@HMS\_Irruncible](#): > > This is not different from what I said. The fissionable material is the limiting component. Not the hydrogen. The “Tsar Bomba” test mentioned above proved that you can, at least in principle, build a ridiculously huge bomb without a fissionable casing in the secondary and tertiary stages. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 25, 2019, 2:34pm UTC](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503/40 "2019-07-25T14:34:31Z")
Right, the fissionable material is the limiting component. But once you have that, you can make your bomb as big as you like by adding more hydrogen. [Previous page](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503.md?page=1) [Next page](https://boards.straightdope.com/t/how-many-megatons-of-yield-cold-a-sub-aircraft-carrier-nuclear-reactor-fuel-be-used-to-produce/837503.md?page=3)