The Fukushima No. 1 plant worst-case fallout scenario drawn up by Japan Atomic Energy Commission Chairman Shunsuke Kondo last March 25 assumed winds would carry the radioactive materials to Tokyo, forcing the government to help people “migrate” from the capital.
But Kondo told The Japan Times last month this simulated contamination scenario was an unrealistic overstatement and steps had been taken to prevent the crisis from escalating to such proportions.
“The scenario is total fiction, but we thought about what we might have had to do to prevent an escalation,” Kondo said.
The scenario effectively assumed that a second hydrogen explosion at reactor 1 would force the evacuation of the plant’s crisis responders, and in their absence the spent fuel pools of the reactors would lose their cooling functions and the pools would be breached, spewing more radiation, starting with the one for reactor 4.
The scenario assumed wind could carry the fallout as far as 250 km from the Fukushima plant, possibly including the Tokyo metropolitan area.
Kondo said the chance of this scenario occurring was extremely remote because a strong wind would have to keep blowing in the same direction.
Environment Minister Goshi Hosono, who is in charge of handling the nuclear crisis, meanwhile insisted the government did not immediately publicize the simulation because there would have been enough time to evacuate Tokyo if the worst occurred.
“We didn’t publicize this because it could have caused excessive, unnecessary public anxiety,” he said.
After Kondo’s report was submitted to Hosono, the government prepared remote-controlled concrete pump trucks with long arms that could directly inject coolant water into the spent fuel pools.
Nitrogen was injected into the stricken reactors’ containment vessels to prevent further hydrogen explosions, and massive amounts of slurry, a mixture of sand and water, have been prepared to contain radioactive materials as a last resort.