Think about it... If they were anything of an explosive, I would be sitting in another Okinawa waiting to get set off. Now, multiply it times every major city in the world which have them... We could literly crack the earth if we all decided to set them off as explosives. But they are not, they are just batteries.
I think you are having a tough time distinguishing a nuclear bomb from a nuclear reaction.
A nuclear warhead is built different and when the fission starts it is, let's say, less controlled. There is a dramatic split of atoms and BANG... you have a nuclear explosion.
If a nuclear reactor core is not cooled properly and allowed to heat it begins to melt everything around it and you have a nuclear disaster on your hands...not a simple battery acid leak.
Have you ever heard of Chernobyl?
Chernobyl was a city in the Soviet Union and also was powered by a nuclear reactor. The nuclear reactor had a total meltdown and it killed 56 people outright and wrecked the environment. A city of 336,000 people had to be evacuated and remains abandoned to this very day. A modern ghost town. 800,000 Soviets were exposed to radiation and there have been about 4000 deaths attributed to the meltdown.
Thats some battery leak!