Nuclear Event Basics

Preparation Steps

• Know your area's emergency alert system. A nuclear detonation triggers all available alerts — sirens, phones, TV, and radio.
• Identify the best shelter in your home. Basements and interior rooms on the lowest floor of large, reinforced buildings provide the most protection.
• Prepare an emergency kit. Food, water, medications, and a battery radio for at least 72 hours.
• Understand radiation zones. The danger area from a nuclear blast depends on the weapon size and your distance.

Immediate Actions

If you see a bright flash:

1. Immediately get down behind anything that can block the blast wave — a wall, a car, the ground.
2. Cover your face — the blast wave arrives seconds to minutes after the flash.
3. After the blast, go inside immediately — the fallout cloud begins descending within 10–15 minutes.
4. Choose the best shelter. Concrete and brick buildings block radiation. Basements are best. Avoid wooden structures.
5. Seal yourself in. Close all windows, doors, and fireplace dampers. Turn off ventilation systems.
6. Remove and bag your outer clothing if you were outside — this removes ~80% of fallout particles. Shower with soap and water.
7. Stay inside for at least 24 hours. Radiation levels drop by ~90% in the first 24 hours after fallout.

The 7-10 Rule: Radiation intensity decreases by a factor of 10 for every 7-fold increase in time after the blast.

What to Avoid

• Do not rush outside to see what happened — fallout is invisible.
• Do not use your car as shelter unless no building is available — buildings block far more radiation.
• Do not take iodide pills unless directed by health authorities and you are near a nuclear power plant incident. They only protect the thyroid from radioactive iodine.
• Do not eat or drink anything that may have been exposed to fallout outside.
• Do not return home until authorities declare it safe.

Supplies Needed

• Emergency radio (battery or hand-crank)
• 72-hour food and water supply per person
• N95 respirators (reduce inhalation of fallout particles)
• Plastic sheeting and duct tape (to seal doors/windows)
• Prescription medications
• Dosimeter or radiation monitor (optional, increasingly affordable)
• First aid kit

Recovery Steps

• Wait for official all-clear. Do not leave shelter based on your own judgment of the situation.
• Decontaminate before re-entry. Remove shoes and outer clothing outside.
• Discard contaminated food and water. Any food or water that was outside and unprotected during fallout should be discarded.
• Seek medical care for radiation exposure symptoms: nausea, vomiting, hair loss, skin burns.
• Follow decontamination instructions from local emergency management.