5 ms·

Clearly I am wrong, but my understanding was a fire would not be enough to initiate the nuclear reaction. Don't two unstable masses have to slam into each other

Clearly I am wrong, but my understanding was a fire would not be enough to initiate the nuclear reaction. Don't two unstable masses have to slam into each other at super high velocity to release enough nuetrons to start the chain reaction?

Rafert 7y ago
That's covered in the article: > If this had happened in the 1980 accident, the rocket motors in the SRAMs, as well as the conventional explosives inside their W69 warheads, used to initiate the thermonuclear reaction, would very likely have exploded. While this may not have triggered a nuclear explosion, it would have thrown a plume of highly radioactive plutonium into the air, easily covering a 60 square mile area, which would have included parts of North Dakota and Minnesota.
- khuey 7y ago
  There's a part further down where they mention that the other type of bomb had a design flaw that could have led to a nuclear detonation under the conditions.
  - moltensodium 7y ago
    "Oops"
olex 7y ago
According to the article, the W69 would not have detonated their nuclear payload, but there was a significant risk of their conventional explosives (used to compress the nuclear mass for detonation) as well as rocket engines igniting and spreading the radioactive payload in a "dirty bomb" manner. Also, in the other type of bomb that was on board there apparently was a design flaw that could've actually triggered the nuclear detonation after prolonged exposure to extreme heat.
- giancarlostoro 7y ago
  > Also, in the other type of bomb that was on board there apparently was a design flaw that could've actually triggered the nuclear detonation after prolonged exposure to extreme heat. So who found that bug and how? I mean... Yikes.
  - tolien 7y ago
    It was a known issue that setting explosives on fire makes them...quite unhappy (hence why nowadays the detonators mostly use insensitive explosives [1]). In the context of a partial/asymmetrical detonation around a warhead - they tried it! [0] 0: https://en.wikipedia.org/wiki/Project_57 https://en.wikipedia.org/wiki/Project_57 1: https://en.wikipedia.org/wiki/Insensitive_munition https://en.wikipedia.org/wiki/Insensitive_munition
rjsw 7y ago
An even more dangerous bomb was the Violet Club [1], an airplane couldn't land with one on board. [1] https://en.wikipedia.org/wiki/Violet_Club https://en.wikipedia.org/wiki/Violet_Club
- jdsully 7y ago
  They literally put a bag of ball bearings into the hollow interior of an enriched uranium sphere (to prevent its accidental implosion which would set off the bomb). Even scarier they didn't really know if this would actually work, but it was better than doing nothing.
  - tolien 7y ago
    The Atomic Weapons Establishment was doing Minimum Viable Product before it was cool to build MVPs! More seriously, most of the reason they cobbled this together was because the US suddenly cut off access to research after WW2 (because of the McMahon Act [2]) and the UK had to look as if they were an independent member of the Big (nuclear) Boy's Club. Between this and the Windscale fire [1], that could've led to absolute disaster. 1: https://en.wikipedia.org/wiki/Windscale_fire https://en.wikipedia.org/wiki/Windscale_fire 2: https://en.wikipedia.org/wiki/Atomic_Energy_Act_of_1946 https://en.wikipedia.org/wiki/Atomic_Energy_Act_of_1946
  - dash2 7y ago
    "At least one accident, dated 1960, was reported in the press when the plastic bung was removed and 133,000 steel ball bearings exited onto the aircraft hangar floor, leaving the bomb armed and vulnerable." Wow. Real Dr Strangelove stuff.
moltensodium 7y ago
If the conventional explosives around a warhead go off in an uncontrolled manner then they are almost certainly not going to kick off a nuclear chain reaction. Things have to happen at a very specific time. But what you're going to get is a massive plume of weapons grade plutonium flying in all directions. Depending on where this happens and the wind this could be the end of a few million people.
- dboreham 7y ago
  If you read the literature it turns out that's in some cases wishful thinking. You'd never get full yield, but no chain reaction turns out to not be guaranteed in the older designs.
  - moltensodium 7y ago
    Can you point me towards what you read on this outside of the article? Not doubting you it's just been like 500 years since I studied nuclear chem and I'm not sure what literature you're talking about.
    - agurk 7y ago
      A good introduction is Eric Schlosser's Command and Control. For the points here the concept of one-point safe is the idea of if a nuclear device is likely to detonate in an uncontrolled situation. A good definition I found was[0]: > What is one-point safe? > Apart from preventing unauthorized use, it is equally important to ensure that the weapons do not explode accidentally. For example, if it is accidentally dropped during transportation (such incidents have occurred), it should not explode. A nuclear weapon is one-point safe if, when the High Explosive inside the weapon is initiated and detonated at any single point, the probability of producing a nuclear yield exceeding 4 pounds TNT equivalent is less than 1 in one million. A surprising number of early nuclear devices were not one-point safe. [0] http://www.nucleardarkness.org/nuclear/nuclearandconventionalweapons/ http://www.nucleardarkness.org/nuclear/nuclearandconventiona...
- nabla9 7y ago
dboreham 7y ago
No. That's how only one bomb worked (little boy). All other bombs use the implosion technique. One mass and the implosion changes its shape/density.
GhettoMaestro 7y ago
The high explosives surrounding the core are triggered by electronic firing (today). I assume this is the most "weak" part of the firing chain physically.

Rafert 7y ago

That's covered in the article: > If this had happened in the 1980 accident, the rocket motors in the SRAMs, as well as the conventional explosives inside their W69 warheads, used to initiate the thermonuclear reaction, would very likely have exploded. While this may not have triggered a nuclear explosion, it would have thrown a plume of highly radioactive plutonium into the air, easily covering a 60 square mile area, which would have included parts of North Dakota and Minnesota.

khuey 7y ago
There's a part further down where they mention that the other type of bomb had a design flaw that could have led to a nuclear detonation under the conditions.
- moltensodium 7y ago
  "Oops"

olex 7y ago

According to the article, the W69 would not have detonated their nuclear payload, but there was a significant risk of their conventional explosives (used to compress the nuclear mass for detonation) as well as rocket engines igniting and spreading the radioactive payload in a "dirty bomb" manner. Also, in the other type of bomb that was on board there apparently was a design flaw that could've actually triggered the nuclear detonation after prolonged exposure to extreme heat.

giancarlostoro 7y ago
> Also, in the other type of bomb that was on board there apparently was a design flaw that could've actually triggered the nuclear detonation after prolonged exposure to extreme heat. So who found that bug and how? I mean... Yikes.
- tolien 7y ago
  It was a known issue that setting explosives on fire makes them...quite unhappy (hence why nowadays the detonators mostly use insensitive explosives [1]). In the context of a partial/asymmetrical detonation around a warhead - they tried it! [0] 0: https://en.wikipedia.org/wiki/Project_57 https://en.wikipedia.org/wiki/Project_57 1: https://en.wikipedia.org/wiki/Insensitive_munition https://en.wikipedia.org/wiki/Insensitive_munition

rjsw 7y ago

An even more dangerous bomb was the Violet Club [1], an airplane couldn't land with one on board. [1] https://en.wikipedia.org/wiki/Violet_Club https://en.wikipedia.org/wiki/Violet_Club

jdsully 7y ago
They literally put a bag of ball bearings into the hollow interior of an enriched uranium sphere (to prevent its accidental implosion which would set off the bomb). Even scarier they didn't really know if this would actually work, but it was better than doing nothing.
- tolien 7y ago
  The Atomic Weapons Establishment was doing Minimum Viable Product before it was cool to build MVPs! More seriously, most of the reason they cobbled this together was because the US suddenly cut off access to research after WW2 (because of the McMahon Act [2]) and the UK had to look as if they were an independent member of the Big (nuclear) Boy's Club. Between this and the Windscale fire [1], that could've led to absolute disaster. 1: https://en.wikipedia.org/wiki/Windscale_fire https://en.wikipedia.org/wiki/Windscale_fire 2: https://en.wikipedia.org/wiki/Atomic_Energy_Act_of_1946 https://en.wikipedia.org/wiki/Atomic_Energy_Act_of_1946
- dash2 7y ago
  "At least one accident, dated 1960, was reported in the press when the plastic bung was removed and 133,000 steel ball bearings exited onto the aircraft hangar floor, leaving the bomb armed and vulnerable." Wow. Real Dr Strangelove stuff.

moltensodium 7y ago

If the conventional explosives around a warhead go off in an uncontrolled manner then they are almost certainly not going to kick off a nuclear chain reaction. Things have to happen at a very specific time. But what you're going to get is a massive plume of weapons grade plutonium flying in all directions. Depending on where this happens and the wind this could be the end of a few million people.

dboreham 7y ago
If you read the literature it turns out that's in some cases wishful thinking. You'd never get full yield, but no chain reaction turns out to not be guaranteed in the older designs.
- moltensodium 7y ago
  Can you point me towards what you read on this outside of the article? Not doubting you it's just been like 500 years since I studied nuclear chem and I'm not sure what literature you're talking about.
  - agurk 7y ago
    A good introduction is Eric Schlosser's Command and Control. For the points here the concept of one-point safe is the idea of if a nuclear device is likely to detonate in an uncontrolled situation. A good definition I found was[0]: > What is one-point safe? > Apart from preventing unauthorized use, it is equally important to ensure that the weapons do not explode accidentally. For example, if it is accidentally dropped during transportation (such incidents have occurred), it should not explode. A nuclear weapon is one-point safe if, when the High Explosive inside the weapon is initiated and detonated at any single point, the probability of producing a nuclear yield exceeding 4 pounds TNT equivalent is less than 1 in one million. A surprising number of early nuclear devices were not one-point safe. [0] http://www.nucleardarkness.org/nuclear/nuclearandconventionalweapons/ http://www.nucleardarkness.org/nuclear/nuclearandconventiona...
nabla9 7y ago

dboreham 7y ago

No. That's how only one bomb worked (little boy). All other bombs use the implosion technique. One mass and the implosion changes its shape/density.

GhettoMaestro 7y ago

The high explosives surrounding the core are triggered by electronic firing (today). I assume this is the most "weak" part of the firing chain physically.