Once again, some not so bright human being, pushed the wrong button and sent out a (mistaken) warning of nuclear attack. What's different this time is... where would all those people have scurried to when told to 'seek shelter'? Most of our Public Civil Defense shelter system is gone or is moldering away in lost and forgotten locations.
If a nuclear attack came - would everyone who was not in a 'fallout shelter' be doomed? No! Well- yes. If you are in the path of high levels of radioactive fallout you must protect yourself or you are going to have a bad day. But protecting yourself does not mean the only form of safety is hunkered down for two-weeks inside of a 50's era 'Bert the Turtle' underground bunker.
The danger is Fallout; very fine dust that comes from soil and debris sucked up into the air by the atomic explosion. (Right now, we are specifically talking about a radiation hazard downwind and outside of the initial blast effect zone - which is 99.9% of US real estate). The need is to stay away from this dust until it's radioactivity has 'decayed' or worn out ( sorta like a flashlight going dimmer as the batteries lose their charge).
During the Cold War everyone talked in terms of World War Three - a big shoot-em up with the Soviets involving hundreds or thousands of really big bombs. Obviously anything less than that is going to mean less danger- relatively.
The three things that are your friend when it comes to sheltering against radioactive fallout are 1) mass: big heavy stuff that separates you from the dust. 2) distance: the farther away you are from the dust the more it's nasty little rays are diluted think of sitting close or far from a campfire. 3) time: the more time that passes, the more the radiation fades away remember the flashlight and batteries analogy.
To make it simple, and shorter, I will use my home as an example. I have a basement- so I am way ahead in this game. Part of my basement has small windows. If I have time, and fallout usually takes some time to drift to your area with high altitude winds and the fall back down, I can go outside and pile dirt over those windows with a shovel. I can also put wood, bricks, my outdoor grill, even park my car against that part of the house. Anything to get 1) mass and 2) distance between the dust and those glass openings. ( I said openings - but any solid material, even glass, that keeps the dust away from me is a good thing!)
Let's backtrack for a moment. First and foremost you want to be inside! You want to keep the fallout dust outside of your inside; literally and figuratively. If you are away from the blast area and your roof,walls and windows are intact and not damaged that is a very good thing.
Back down to my basement. Most of this below ground space has no windows, so it's at the windowless end, in a corner, that I am most protected. In a corner I have the surrounding soil on 2 sides for protection. The lower to the floor level I am the more protection I have. Three feet or more of soil is pretty good mass to keep away Mr. Radiation. It may be that the best place for me is more to the center of the basement space. That location gives me the ground protection plus the distance of the entire volume of the sealed house. The wooden walls and floors of the house above aren't much in the way of shielding, but in the basement I am 10 to 30 feet away from the outside walls and roof and that distance can count for a lot. Remember too; smaller bombs and smaller wars may make my problems less than in the days of Curtis LeMay vs. Khrushchev.
If you have no basement and or live in an apartment building remember that distance from the outside will always help. Stay to the center of the structure. Create mass for shielding by bringing in garbage bags filled with soil, stacking furniture and boxes of books. If it is heavy it has mass and makes for good shielding.
