Dr. Michio Kaku is at it again, on Good morning America this Saturday morning. But this time, it is appropriate that it was a physicist that spoke about the damaged Japanese nuclear plants. This was a few hours after a large explosion at one of them that may have destroyed the outer building. He basically said that if the inner reactor core, which is apparently still intact, was destroyed or badly damaged we could have a Chernobyl on our hands. He said that word twice. But, while that kind of statement could contribute to panic in Japan, if he knows what he is talking about, I think it was OK to say.

The evacuation zone was expanded from 10 km to 20 km radius around this plant (to 12 miles). Kaku suggested it should now be 20 miles. I suspect he drew that number out of his hat. Did he study populations there and escape routes? Why not 50 miles? Why not leave it as 12?

The link below was before the explosion
it says:
"But the risk of contamination can be minimised as long as the external container structure is intact, they said. The worry then becomes whether the quake has weakened the structure.

There has been no official word so far on whether the structure was damaged in the quake.

Japanese officials and experts have been at pains to say that while there would be radiation leaks, they would be very small and have dismissed suggestions of a repeat of a Chernobyl-type disaster.

"No Chernobyl is possible at a light water reactor. Loss of coolant means a temperature rise, but it also will stop the reaction," Naoto Sekimura, a professor at the University of Tokyo, said.
"

Kaku seemed to disagree with this, and knew what type of reactor they had there. He also said that the Japanese nuclear industry has a bad track record of downplaying problems.
Chris

• Japan nuclear plant vs. Chernobyl