What objects could survive a close-up nuclear explosion?

General Questions
#21

The early Operation Crossroads nuclear tests were done in part to test the effects of nuclear weapon detonations on warships, with some 95 decommissioned military ships subected to airbursts and waterbursts of Nagasaki-type weapons (approx. 23kt yield). In general, ships within 1000 yards of the detonation point suffered heavy physical damage; ships within 400 yards mostly were sunk. A barge used to support the underwater test and located about 80 feet directly above the weapon apparently was vaporized, with no identifiable parts found.

Although most ships outside 1000 yards suffered relatively minor damage, their crews would have been exposed to lethal amounts of direct radiation from the blasts, even in interior spaces. Also, relative physical damage had much to do with the ship’s orientation relative to the blast; stern or bow-on tended to survive better than a broadside orientation.

#22

Yes, but that warhead is so light weight that the submarine launched missile can cram in 14 of them. (apparently, due to international agreement they load in fewer, but still)

#23

Well thats silly.

The heat from blasts will turn most small objects to plasma, and plasma is surely never going to make any more phone calls.

The steel structure was all burnt because it all got hot at once, even though it could conduct heat away , it didn’t have anywhere to conduct it to …
But the ground … well the ground didn’t turn to a pool of molten lava …
It had the ground lower down to conduct heat to.

Seems to me proved that a large enough object that can protect itself by having its insides or lower sides act as a heat sink …Distribute the heat, keep the temperature low… (temperature is the density of heat…)

#24

Hmm. Trinity was about 20kt, and 1kt = 4.2e10+12 J, roughly, so you’re talking about 84 TJ of energy, and I assume you want something that will survive at the base of a 100ft tower, so we’re going to distribute that energy over a fireball of 100ft radius. It’s mostly filled with (very hot) air, and air has a density of 1.3 kg/m^3. So there is about 1.5e+05 kg of air in the fireball. Assuming an average molar mass of about 14 g/mol, we have about 5.5 million moles of air, and distribution 84 TJ through it gives about 15,000 kJ/mol. Dividing by 3/2 R gives a temperature of about 1.2 million kelvins, which is the same in degrees Celsius, pretty much, ha ha.

So what you are looking for is something that can survive that kind of temperature for a few seconds, long enough for the fireball to cool down to something reasonable. Obviously no material substance can survive that as an equilibrium temperature, but fortunately you don’t need that – you just need the stuff to survive the few seconds required for the temperature to fall lower, or another way to put it is that you need it to be able to absorb a whomping huge pulse of heat but not be destroyed. I don’t see why you couldn’t design an ablative shield that would do the trick pretty easily. You need to absorb a maximum of 15,000 kJ/mol, and the heat of vaporization of, say, graphite is like 300 kJ/mol. I would guess a solid foot of graphite ablative material would survive the fireball.

Next you’d need to survive the pressure wave, however. I can’t think of an easy back of the envelope way to estimate what the overpressure is 100 ft from the detonation, but when I take a look at a blast overpressure predictor, like here:

http://meyerweb.com/eric/tools/gmap/hydesim.html

The overpressure seems reasonably well-approximated by p = 2.5*d^(-1.5), with p in PSI and d in miles. Extrapolating back to 100 ft (19 millimiles) gives p = 960 PSI or 65 atmospheres. Damn high, to be sure, but certainly well within the ability of conventional (e.g. deep-sea) engineering, to construct a structure that can withstand that kind of overpressure. You put your ablative shield on top of that.

The estimated cost is left as an exercise for the reader.

#25

I realize you are joking, but the sound produced by phones vaporizing in a nuclear explosion was a major plot device in Fail-Safe.

A flight of 6 US bombers accidentally gets the go code to attack Moscow, and despite the best efforts of Soviet air defense even with US assistance one of the bombers makes it through to Moscow to drop its bomb. The squeal of the phone melting from the blast while talking to an emissary in Moscow confirms the failure to stop the last bomber from delivering its nuclear payload, and in order to prove to the Soviets that the attack was truly accidentally launched and not being used as the cover to land a decapitating strike on the USSR, the president orders another bomber which has been orbiting New York City to drop a bomb of the same yield on the city. The pilot of the bomber, whose wife and family were in NYC, kills himself with a cyanide capsule after ordering the bomb dropped. Depressing movie all around.

#26

I have alway wondered how…representative the test was. IRL a ship would be filled with munitions and fuel, both if which would presumably explode.

#27

Indeed—luckily, there’s an online simulator available. With instructions here, among other places. (The fourmilab.ch link also has a simulated/animated version, but theirs never worked correctly. The figures from one from the first link, on the other hand, I’ve been able to successfully verify against other sources. There’s also an iPad app.

Personally, though, I’ve been favoring the latest version of the Nukemap site, which has a far more versatile array of weapon calculations available…including casualty estimates.

Fun fact: If you dropped the largest nuclear weapon ever tested on the geographic center of North Dakota, you’d kill almost…800 people.

Incidentally, I’ve got photographic evidence of something that did survive a nuclear blast at point blank range: the test tower of Upshot-Knothole Ruth. A 200 ton (sic) fizzle. :smiley:

#28

I used to think that was the case as well but apparently in one US test they detonated the device with several spheres of a carbon material next to it. These spheres were found some distance away, charred but intact.

Unfortunately I can’t recall where I read that and google is turning up nothing relevant.

Ah-hah, Project Orion strikes again, its mentioned on this page, search for ‘graphite-covered steel spheres’:

http://www.orbitalvector.com/Deep%20Space%20Propulsion/Nuclear%20Pulse%20Drives/Nuclear%20Pulse%20Drives.htm

#29

I know this one. It’s a fridge, right?

#30

Guys, as stated in the OP:

The OP provided a cite for something which survived being in the nuclear fireball, and the question is “what else?” If the answer is “nothing else”, that’s fine, but several people here are saying “nothing can survive.” Which is it?

#31

The other major avantage was that the dome was sheet copper. The flash vaporized it, or else the blast wave would have crumpled the steel beams, using the copper sheeting as sails. With the dome sheeting gone, the iron beams presented a very small cross-section to the blastwave.

The tower itself still stands because the blast was almost directly overhead, so the blast did not push the masonry walls sideways like most other buildings.

Beyond a certain point, the effects of a blast are basically the same as any other compression blast; close by, it’s a massive blast of heat and penetrating radiation that can vaporize or incinerate like any other sudden heat source. There’s nothing magical about an atomic blast except its immense power.

One item I read suggested that top-end cold war weapons, in the 50MT or more range, would for example start forest fires on the hills around Los Angeles up to 50 miles away.

#32

The parts of the tower foundation remaining in that photo must have been quite a ways below ground (i.e. they were standing in the explosion’s crater). The intensity of the fireball had to dissipate as it vaporized the soil & concrete above it.

Something else I noticed in that picture: Groves has already been promoted to Maj. General. When the test bomb was a success one of the scientists commented that it was, “As bright as a star”, to which Groves famously replied, “Bright as two stars!”

#33

Diamonds can be readily shattered or burned (they’re made of carbon).

#34

I was looking for that, thanks. Disposable Hero has found one possible answer to the question; in particular this part

Somewhat disappointingly, this only refers to ‘popular lore’; but seemingly Freeman Dyson calculated that the pusher plate on the Orion Ship would survive a series of explosions, enough to lift hundreds of tonnes into orbit.