Both stressed that even in the worst case scenario — if the cooling systems fail, leading to a reactor meltdown — it would only cause serious damage at a local level. Cizelj estimated a 30-kilometer radius.
What if a nuclear weapon were used? At Zaporizhzhia, the large amounts of spent fuel storage make this risk even worse. Fallout would create a lethal radiation risk across the entire plant site and city of Enerhodar.
Although some windows may be broken over 10 miles (16 km) away, the injury associated with flying glass will generally occur at overpressures above 0.5 psi. This damage may correspond to a distance of about 3 miles (4.8 km) from ground zero for a 10 KT nuclear explosion.
How large an area was affected by the radioactive fallout? Some 150,000 square kilometres in Belarus, Russia and Ukraine are contaminated and stretch northward of the plant site as far as 500 kilometres. An area spanning 30 kilometres around the plant is considered the “exclusion zone” and is essentially uninhabited.
As a result of the Chernobyl disaster, the Soviet Union created an exclusion zone with a radius of about 18.6 miles (30 km) centered on the nuclear power plant, covering 1,017 square miles (2,634 square km) around the plant.
Cizelj estimated a 30-kilometer radius. “It will be a tragedy for the local people,” he said, even if it would create no immediate casualties, but “for us in Europe … it would be a very unimportant event, in terms of consequences for health or anything else in the environment.”
At 40 miles high, it penetrated the stratosphere. Everything within three dozen miles of the impact was vaporized, but severe damage extended to 150 miles radius—enough to entirely annihilate any modern major city, including suburbs.
The initial radiation pulse from a 1 KT device could cause 50% mortality from radiation exposure, to individuals, without immediate medical intervention, within an approximate ½ mile (790 m) radius. This radius increases to approximately ¾ mile (1200m) for a 10 KT detonation.
If you lived within 50 miles of a nuclear power plant, you would receive an average radiation dose of about 0.01 millirem per year. To put this in perspective, the average person in the United States receives an exposure of 300 millirem per year from natural background sources of radiation.
131-I has a short physical half life of 8 days, and therefore significant amounts of this isotope would be unlikely to reach neighbouring countries.
If a crisis at a nuclear reactor happened in the U.S., could you be living in a danger zone? In a 10-mile radius, the Nuclear Regulatory Commission says the air could be unsafe to breathe in the event of a major catastrophe. In 50 miles, food and water supplies may be unsafe.
The plans define two “emergency planning zones.” One zone covers an area within a 10-mile radius of the plant. This 10-mile area is where people could be harmed by direct radiation exposure.
There have only been two major accidents at nuclear power plants, and their impacts have been far less severe than widely feared. Nuclear is the safest energy source we use anywhere in the world.
"The level of radioactive pollution, and most importantly the area of contamination, will be thousands of square kilometres of land and sea… it would be much, much worse than Fukushima and worse than Chernobyl."
Risk of nuclear terrorism
Besides its six nuclear units, Zaporizhzhia NPP contains facilities to store used nuclear fuel and radioactive materials, including liquids. These facilities are vulnerable to shelling or air strikes, which will mean radioactive pollution over a large territory.
If it blows up, it will be 10 times larger than Chornobyl! Russians must IMMEDIATELY cease the fire, allow firefighters, establish a security zone! The Zaporizhzhia nuclear power station is 310 miles from Chernobyl and has a total capacity of 5.7 gigawatts, enough to power over 4 million households.
If something happens to go wrong at a nuclear reactor, anyone living in a 10-mile radius of the plant may have to evacuate. This map also shows a 50-mile evacuation zone, the safe distance that the U.S. government recommended to Americans who were near Fukushima.
Shielding: Barriers of lead, concrete, or water provide protection from penetrating gamma rays. Gamma rays can pass completely through the human body; as they pass through, they can cause damage to tissue and DNA.
During any radiation emergency, follow the radiation protection principles of time, distance, and shielding. Limit your time exposed to radiation, stay as far away as possible from a radioactive source, and shield yourself from radiation by going deep inside a sturdy building. If the emergency is outside, Get inside.
THE NEXT 48 HOURS
You have been sheltered because of the potential for dangerous levels of radiation in the first 24 hours following a nuclear detonation. After 24 hours, outdoor radiation levels will have fallen significantly but may still warrant protective measures in your area.
While an underground shelter covered by 1 meter (3 feet) or more of earth provides the best protection against fallout radiation, the following unoccupied structures (in order listed) offer the next best protection: Caves and tunnels covered by more than 1 meter (3 feet) of earth.
Radiation levels are extremely dangerous immediately after a nuclear detonation, but the levels reduce rapidly, in just hours to a few days. This is when it will be safest to leave your shelter and participate in an orderly evacuation.
Russia's Tsar bomba: World's most powerful nuclear weapon of mass destruction.
BUILD UNDERGROUND
Building down to a depth of about ten feet will provide ample protection, but any deeper makes it hard to dig out in the event of a collapse.
A new video simulates the explosion of thermal nuclear weapons in the Challenger Deep. Tsar Bomba is the most powerful nuclear bomb ever made. One bomb would be stanched, but a million could easily destroy the Earth.