The problem is the spent fuel rods that are NOT encased in 6" thick stainless steel, but are/were being stored in concrete ponds that have been damaged?
These spent fuel rods are still highly radioactive and supposed to be submerged in water to prevent them from overheating.
Since the concrete ponds were damaged (I guess by the hydrogen explogions) the spent fuel rods are not submerged in water and are, without question, overheating.
According to the research I've done, this has never happened before.
Spent fuel rods have never gone so long without being cooled.
So the scientist aren't sure what's going to happen to those fuel rods.
They may catch fire and/or explode and that would put radioactive particles into the atmosphere similar to what happened at Chernobyl, but on a MUCH larger scale.
The spent fuel rods are not within the steel reactor housing.
So here's the bad news...
The Japanese have/had hundreds of spent fuel rods in these concrecte ponds.
If that isn't bad enough for you, many of the spent fuel rods have plutonium in them.
Plutonium radiation is much more dangerous than uranium radiation and plutonium generates a lot more heat than uranium does.
The plutonium rods are stored in concrete ponds on top of reactor 3.
Restoring the cooling system to reactor 3 is the top priority for the Japanese.
Today's hydrogen bombs have a few hundred milligrams of plutonium in them.
The Japanese have several hundred kilograms of plutonium and uranium in the fuel cels that are stored in the concrete ponds and are now overheating.
The reactors at Chernobyl didn't have ANY plutonium in them, only uranium.
The explosion at Chernobyl resulted in a 19 mile (30 km) radius being rendered uninhabitable (for at least 20,000 years!!!).
A 19 mile (30 km) radius is roughly 1,000 square miles (1880 km²).
The situation in Japan has the potential to become a Cherenobyl on steroids.
Every nation on earth is trying to evacuate their citizens from Japan.