There's an interesting article on Io9 about surviving a low-yield nuclear attack on your city. "Low-yield" here means in the 0.1 - 10 kiloton range that a terrorist might improvise, rather than the megatons a serious government could muster.

The timeline seems to be, first a bright flash. A shockwave follows some seconds later, because it travels more slowly than light. It can shatter windows, so don't go look out of one when you see the flash. Then there's some minutes of intense radiation. This fades quickly, and after about half an hour it can be worth moving out to seek a building that provides better shelter, if you know of one. At this point you're avoiding fallout. The worst of the fallout will have a relatively short half-life, and after 24 hours will should be safe to go outside for evacuation. Ideally, wait for emergency responders who will have better knowledge of fallout patterns and safe evacuation routes.

There's more detail in the article and linked paper. Perhaps the key point is that such incidents are survivable, as long as you aren't too close to ground-zero.

Well it will be more than just a bright flash, it will be a thermal flash with intense heat. What you wear day to day (assuming there is absolutely no warning) could prove the difference between live and death. Polyesters, nylon and other synthetics may well ignite or melt into the skin. Wool clothing will help considerably. Many will be blinded etc. Many folks won't instinctively duck and cover for the blast wave front.

The blast wave will destroy quite an area of property much depending on the construction. An air burst will generally destroy more property than a ground burst. A ground burst will generally generate more fall out.

Protection from fall out is best shown here;

http://www.youtube.com/watch?v=m6U9T3R3EQg



Typically staying in the protection shelter is 10-14 days. An NBC suit and respirator could prove very useful and can be had for less than £100. A portable Geiger counter would be useful as well for measuring the intensity of the fall out and its decay rate over a period of time.

re: thermal flash... in 1971, I was stationed on the southern Japanese island of Kyushu, about 60 miles north of Nagasaki... I was introduced to a lady that was a student nurse in 1945, and on the day of the bomb, she said she was about 12 miles from Nagasaki... she had fine line scars on her arm and shoulder... the pattern of dark embroidery on the white cloth of her kimono had absorbed enough energy to burn her arm in that pattern

And based on another recent thread we're all wearing fleece! Where do our preparations end...

Some of us are wearing wool beneath the fleece Will skin be protected from the melting polyester fleece by a thin layer of Merino Wool?

If you are wearing DragonFleece (Nomex) you don't have that problem.

Respectfully,

Jerry

Brangdon,

"Low-yield" here means in the 0.1 - 10 kiloton range that a terrorist might improvise, rather than the megatons a serious government could muster.

Really makes little difference, except on the distance from each required to avoid the initial heat and the time available to hide (longer from the larger blast).

AFLM,

The thermal flash from a ground blast (see original post) of low yield, will not provide a thermal blast that is a problem for very far. Buildings, terrain, trees,etc. will block the thermal effects at distances much beyond the serious damage zone. An air burst would provide a different problem.

Respetfully,

Jerry

I have some Massif(.com) nomex fleece but it's not for everyday wear. I also have more than a couple nomex flight suits which would be really nice to wear, but again, they're not an everyday thing. Terr's will need to give us a heads up when this thing is going down... yeeeah, that's not gonna happen.

Since there tends to be a fair amount of incorrect info regarding all things radioactive and nuclear on this forum, I thought I would post some more accurate info regarding the current topic.

Damage Zones for the Yields being discussed:
Damage Zones

Hypothetical Fallout Zone (which is of course dependent upon environmental factors at the time of the event):
Fallout Zone

I hope this gives people some accurate info to base their sheltering in place or evac planning on.

From the graphic we can see that the severe blast radius is approx 50% @ 1Kt to the 10Kt Radius. i.e. Yield to blast radius it is not linear.

Hiroshima was 16 Kt, which killed 90,000–166,000 people.
Nagasaki was 21 Kt, which killed 60,000–80,000 people.

I also have it from a good source that almost as many died from the fall out effects.

A low yield 1 Kt explosion would typically kill around 20,000-30,000 (blast and fall out) people in a high density population centre with many suffering severe burns.