There are no easy answers when one asks how to survive a nuclear attack. Much depends on where you are when a nuclear device is detonated, how many megatons the bomb is along with weather and wind currents. If you are at ground zero, in the kill zone, you have no chance. Outside of the kill zone, shielding, distance and time, factor in on whether you survive or not.
A one-megaton surface blast will be fatal to all humans within a 1.7 to 2 mile radius, and within 0.6 miles, all buildings will be destroyed. Destruction will be from the blast pressure and thermal heat. Only a few of the sturdiest structures will be left standing at the 1.7 to 2.0 mile radius. The kill ratio could be 50 percent or more with 40 percent or more sustaining some sort of injury out to seven miles from the blast center. The fallout depending on wind speed and other weather factors can be 90 miles or more. Obviously, a larger megaton bomb will have an expanded kill radius and fallout zone. For example, a 25-megaton bomb detonated on the surface will have a 98 percent kill rate up to 10.7 miles while anything or anyone with a 6.0-mile radius will be destroyed.
These figures are approximate and are only for informational purposes. Many factors must be considered before determining the kill zone to include type of material used, Pounds per Square Inch (PSI) and air or surface detonation.
Shielding is protection, such as specially designed barricades, against blast pressure, thermal heat and radioactive fallout. Barricades/shields can be lead lined rooms, underground bomb shelters, steel and concrete buildings, soil, water, snow and body suits. Distance from the blast determines how much your body will absorb and time exposed to radiation has a direct correlation on how much your body will absorb as well. Your objective is to shield your body, limit your time exposed and put distance between you and the blast.
First, realize it can happen; denial of the facts is counter-productive. The first thing some victims of a disaster proclaim is, “I never thought it would happen”, thus, they did not prepare. You have to assume you may be away from your home when the blast occurs. The time from when the blast occurs until you are aware of it is crucial. You may even hear the blast, which means the clock begins ticking on time exposed to fallout. You immediately want to put distance between you and the blast area and shield yourself once out of the area. Unless your work place has a bomb shelter, you must move away from the blast. If you have a bomb shelter or underground bunker at home and it is away from the blast area move there as quickly as possible.
Shielding for the average citizen can be anything from heavy clothes and face masks to bomb shelters, basements, a culvert or even a depression in the ground. Buildings between you and the blast area will offer some protection, as well as hills, and heavy foliage. Your objective is to put as many barricades between you and the detonation.
Like for any disaster, planning is essential. Therefore, assuming you will not be at ground zero they are things you can do to prepare for a nuclear disaster. Shielding, do you have a bunker or underground bomb shelter. Putting concrete, steel and/or and layers of soil between you and the fallout is your best protection. Your basement can be used as a fallout shelter, and to prepare it you must have the materials to seal off the room from the outside without sealing off your air supply. If you have, entrances to the basement from inside and outside the home seal the doorways behind you with plastic sheeting and duck tape. Do the same with your home if you do not have a basement or bomb shelter. You cannot completely stop the fallout, unless you have a specially designed bomb shelter, but you can limit it and with enough distance from the blast area, you can reduce your risk and survive.
Nuclear surface detonations are designed to kill people and destroy infrastructure. Therefore, the most heavily populated metropolitan areas are at the highest risk as well symbolic structures and locations. Other high-risk areas include shopping malls, sporting events and were people gather to celebrate, not only do terrorist want to inflict physical damage they want to inflict emotional damage on the populace as well.
Biological agents are silent killers in some aspects. In some cases, it may be impossible to know you are under attack until symptoms are evident or people begin to die, and then it may take days or even weeks to determine the disease or agent and whether it was an intentional attack or not.
Keep in mind many biological agents are passed from human to human. There are other ways of dispersing biological agents however, such as through a water source, bomb detonation or the biological agents can be sprayed over an area from an aircraft. Canisters can be left on subways and buses as well. Protective measures include facemasks, air respirators and/or protective suits. Certain diseases that were thought eradicated or controlled by vaccinations could be introduced into society such as smallpox and flu like viruses. Ensure you and your family is current on all vaccinations and make sure you have the most recent flu shots.
Avoiding exposure is obviously the most effective preventive measure. You cannot of course avoid some situations but you can avoid when possible large crowds, celebrations, buses and subways.
Protections once you know an agent has been introduced into the air, or you know that people are infected include bomb shelters with air filtration systems, respirators (gasmasks), surgical masks, specially designed body suits and your own home. Seal off windows and doors with plastic and duct tape, stay inside, and monitor the latest developments.
All disasters create effects some are immediate and others progress over time such as limited supplies at the grocery store and disruption in utilities such as electricity, gas and water. Regardless of the cause, you may be forced to stay in your home or bomb shelter for an extended period so you will need supplies.
The list is certainly not comprehensive and is designed to give you a starting point. Failing to prepare can mean the difference between surviving and not surviving.