He says with Fukushima, one scenario is that people are exposed to radiation gradually over a long time. That is not a problem. But if later there is a nuclear explosion and people get exposed over the course of couple of days, that scenario really scares me.

Hoshi says he fears information is being hidden from the public about how serious the situation is.

For example, he says, the government says everyone living beyond a radius of 30 kilometers from the plant is OK staying at home. But there are still dangerous areas outside that 30-kilometer zone. He says he believes an 80-kilometer zone, as suggested by the American government, is the far better calculation.

Lessons learned?

Keijiro Matsushima says Japanese people soon forgot the horrors of the atomic bomb after 1945.

“People thought so long as nuclear power is used in peaceful ways, that is OK. But we should have learned the evil of nuclear power from the experiences of Hiroshima and Nagasakim,” he said.

But, says Matsushima, the threat from Fukushima nuclear plant has reminded Japan of what happened back then - and the whole nation fears what may happen next.

“From now on we will have a very hard time. I am afraid so. But we have to do our best to recover and rise up again. Yes we can!” Matsushima said.

It is in that spirit that the firefighters and engineers battling to prevent disaster at Fukushima have been embraced as heroes.