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Okay, I was one of the lucky ones. I was in a windowless concrete building when the bomb went off, and I was far enough away to survive the shock wave and super-heated winds.

Even luckier, I am a fan of antique cars, and my 67 mustang hardtop was parked one floor down in the (also concrete enclosed) garage. Its' pre-computer-age ignition fired up on the first turn of the key and I'm now racing through empty streets, away from the detonation site within 3 minutes of the blast.

Assuming that building, vehicle choices, and clear roads have exhausted my positive karma supply, I glance in the rear view and confirm that yes, a mushroom cloud is rising into the sky behind me, and that the post-blast winds are returning to their natural course, gust-fully chasing me as I flee out of town.

Questions

Given a three minute head start, can the fallout of a 150 kiloton ground-level nuclear blast, terminally irradiate a person during the time it takes for a high speed muscle car to escape the initially contaminated radius? Assume that the person starts in the closest survivable concrete building and that the roads have been recently swept clean (but contaminated) by super heated nuclear winds.

Would the car's tires melt and burst during the first few miles of the escape?

Are there any other issues that I am overlooking, like "the car will overheat" or "the driver will be cooked long before the radiation kills him"?

Should the driver avoid future procreation activities in the years following his lucky survival?

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    $\begingroup$ well first, you need an old refrigerator. $\endgroup$ – King-Ink Feb 11 '16 at 22:51
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    $\begingroup$ how is this about worldbuilding? It seems like a single plot element. $\endgroup$ – nitsua60 Feb 11 '16 at 22:53
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    $\begingroup$ Yes, I know I am stealing from Spielberg, but my protagonist is in his twenties and owns a mustang! Way better than a whip! $\endgroup$ – Henry Taylor Feb 11 '16 at 22:53
  • $\begingroup$ @nitsua60, the immediate vacinity of a nuclear blast is a science fiction world, in the same way as a star-ship bridge. They are environments where stories happen and are therefore world unto themselves, despite being "single plot elements" $\endgroup$ – Henry Taylor Feb 11 '16 at 22:56
  • $\begingroup$ This question does not seem fit for worldbuilding. Possibly more suited for pyhsics se. $\endgroup$ – Quiquȅ Feb 11 '16 at 22:57
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The site Nukemap allows you to calculate and visualize what is going to happen (http://www.nuclearsecrecy.com/nukemap/)

From ground zero, the fireball radius will be .50km, the 20psi air blast radius will be 1.16km (destroys concrete structures) and the 500 rem radiation radius will be 1.94km (immediate radiation pulse, not the fallout) and the thermal pulse radius will be 4.67km (enough energy to cause 3rd degree burns).

So if you are 3 miles away (4.8 km)from ground zero, you are outside of the fireball, but still near the edge of the blast and immediate thermal pulse. I suspect that most of the buildings around you will be collapsed and on fire, and this is before the vaporized and irradiated soil comes back to earth as fallout. Assuming your contractor built your structure to withstand 20psi overpressure (and the building is sealed against overpressure as well, inrushing pressurized air will probably pop your lungs once the pressure increase is more than 6psi), you are now in an island of relative safety.

The time for the fallout to begin descending is going to be dependent on a lot of factors, and the fallout plume will also be determined by the direction of the winds on the day. You may be very lucky with the wind blowing directly away from your shelter, or you could have the fallout plume directly in line with the highway you intend to travel down.

Personally, I would break open the canned tuna, ensure the filtration system is fully functional and wait. Your car escape will involve driving through a firestorm, and the chances of driving over sharp pieces of rubble that can puncture a tire are close to 100%. Even the idea that the roads will be clear of larger pieces of debris is pretty iffy; the 20psi blast wave will be picking up and flinging pretty large objects (in an urban setting you can imagine city buses, delivery trucks and large chunks of concrete and metal structures raining down from the blast). Asphalt roads might even have melted or caught fire as well, which should make for an interesting drive.

While you are waiting, make sure you disconnect the car battery, and it is probably a good idea to jack up the car and place it on blocks to unload the suspension and keep the tires from contacting the ground. Drain the gasoline from the tank (it will eventually turn into varnish) and perhaps change the oil and filters. Depending on the wind, you might be waiting for a while before the fallout clears your area.

And if you want to drive away afterwards, trailer your Mustang and tow it with this:

Landmaster

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  • $\begingroup$ Thanks for the link! Despite my question getting put on hold, I got most of the answer I was looking for. $\endgroup$ – Henry Taylor Feb 12 '16 at 5:25
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It all depends on your starting distance and kind of the bomb. Because modern bombs are classified technology, I'll only sketch it.

Thermal radiation

Visible and infrared light mostly. Travels at the speed of light. There is a lot of it, but it lasts only a short time. If you are far enough your building survived, there probably are some fires around, but not a lot. Asphalt should not be hot enough to melt tires. If your building was really, really sturdy and close, there is a firestorm you don't want to see or drive thorough.

Oxygen in air

Still there, you can breathe, engine can run. Better have good filters, of course, because dust isn't good for lungs or engines, but you'd rather survive. Unless you are close enough to be in firestorm, of course.

Radioactivity

Direct

Not a real concern as it travels at or near speed of light. If you weren't exposed to a flash, you weren't exposed to this, either. Not if your concrete building was thick. See for example this, this or this - concrete can be effective radiation shield, if really thick or poured with proper additions. It's not normally used because lead is better insulation per millimeter of thickness, but actually concrete seems to be better radiation shield per dollar spent and have far superior structural qualities. That's why concrete shields Chernobyl.

Indirect

Some substances are turned radioactive by radiation from the bomb. You don't want to touch, breathe, eat or drink anything. How serious it is? Depends on the bomb, more modern design means less of this effect, as no one really wants to permanently waste terrain.

Fallout

That's what you think you are running from. After initial spread caused by the blast, it moves with the wind. Modern bombs are meant to be as "clean" as possible, creating little to no fallout. Even with older ones, like these from Nagasaki and Hiroshima, you probably could drive far enough to survive. Just don't expect it to have no effects at all. If it's set in future, it's not a big stretch to hope this effect will be negligible.

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    $\begingroup$ I would point out that just because something is opaque to visible light, doesn't mean it is opaque to higher energy photons. (x-rays and gammas) So the Direct portion of your answer addresses only the blinding flash of visible light, not the other zoomies. In addition, these other high energy photons can also alter substances to their more radioactive forms. $\endgroup$ – Seeds Feb 11 '16 at 23:46
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    $\begingroup$ We use lead and similar shielding materials around nuclear sources for a very good reason, most lesser density materials are effectively transparent to high energy photons. And that's just for day to day stuff, like dental xrays, and nuke plants. A bomb is going to put out WAY more of the bad stuff, you want as much density between you and the bomb as possible, otherwise: you can run, but you'll just die tired, and bleeding from the pores. $\endgroup$ – Seeds Feb 11 '16 at 23:53
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    $\begingroup$ @Molot is correct. Although there is some evidence that higher Z elements are slightly more effective, the main determinant is mass. You need a given mass of shielding to be protected, regardless of source for high energy photons. $\endgroup$ – Jim2B Feb 12 '16 at 1:23
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    $\begingroup$ For neutrons though, low Z elements work MUCH better than high Z. In fact, the highest Z elements, just act to scatter the neutrons and don't slow them at all (think - shooting a BB at a bowling ball). $\endgroup$ – Jim2B Feb 12 '16 at 1:25
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    $\begingroup$ @Mołot: In fact, I used to work in such a building (long after it had been repurposed, though). Part of the SAGE defense program of the 1950s, it had concrete walls about 2 ft thick, and was supposed to withstand a nuclear weapon detonated nearby. $\endgroup$ – jamesqf Feb 12 '16 at 4:44

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