How long do you need to stay in a fallout shelter?
It can be hard to gauge when it's safe to emerge from your shelter, but most estimates suggest a minimum stay of 24-hours, and a maximum stay of 14-days - enough time for the initial radiation to fall to (relatively) safe levels.
Recovery would probably take about 3-10 years, but the Academy's study notes that long term global changes cannot be completely ruled out. The reduced ozone concentrations would have a number of consequences outside the areas in which the detonations occurred.
Fallout radiation decays relatively quickly with time. Most areas become fairly safe for travel and decontamination after three to five weeks.
For the survivors of a nuclear war, this lingering radiation hazard could represent a grave threat for as long as 1 to 5 years after the attack.
Close and lock all windows and doors, and close fireplace dampers. When you move to your shelter, use duct tape and plastic sheeting to seal any doors, windows, or vents for a short period of time in case a radiation plume is passing over (listen to your radio for instructions).
First responders must exercise special precautions as they approach the fallout zone in order to limit their own radiation exposure. The dangerous fallout zone can easily stretch 10 to 20 miles (15 to 30 kilometers) from the detonation depending on explosive yield and weather conditions.
Make sure you have an Emergency Supply Kit for places you frequent and might have to stay for 24 hours. It should include bottled water, packaged foods, emergency medicines, a hand-crank or battery- powered radio to get information in case power is out, a flashlight, and extra batteries for essential items.
You must protect yourself from the fallout or you'll have a short life. If you're in a stable structure such as a basement or fire staircase, you can shelter in place for a few days, if necessary. If your building is destroyed, you'll need to move to a nearby intact structure. Block all the doors, windows and air gaps.
A study last month found that the countries with the best hope of at least seeing their civilisation survive during the ten years after a nuclear war would be Argentina and Australia.
Iceland is one of the safest countries in case of nuclear war due to its isolation, lack of military, and geothermal energy. Because Iceland is isolated from the rest of the world by the North Atlantic Ocean, it would be very difficult for a nuclear missile to reach Iceland without being detected first.
Where is the safest place to live if there is a nuclear war?
Antarctica. Antarctica could be the safest place to go in the event of nuclear war because the Antarctic Treaty banned all detonation of nuclear weapons there. It is also far from any major targets.
The bunkers built to survive apocalypse
It is designed for a community of up to 75 people to weather a maximum of five years inside a sealed, self-sufficient luxury habitat. When the event passes, residents expect to be able emerge into the post-apocalyptic world (Paw, in prepper parlance) to rebuild society afresh.
The deeper beneath the soil that the shelter is built, the safer inhabitants are from fallout. The half life involved in nuclear radiation is incredibly long, and no area within many miles will be completely free from radiation. However, within the fallout shelter the radiation will be greatly decreased.
Surface temperatures would be reduced for more than 25 years, due to thermal inertia and albedo effects in the ocean and expanded sea ice. The combined cooling and enhanced UV would put significant pressures on global food supplies and could trigger a global nuclear famine.
The radiation in Hiroshima and Nagasaki today is on a par with the extremely low levels of background radiation (natural radioactivity) present anywhere on Earth. It has no effect on human bodies.