The document was dated March 25, 2011, two weeks after the massive earthquake and tsunami triggered the country’s worst nuclear crisis. It was premised on a scenario in which all plant workers had to be evacuated due to a rise in radiation levels after a hydrogen explosion damaged a containment vessel encasing the plan’s No. 1 reactor.
The document said that should such a case occur, residents within a radius of 170 kilometers or more of the plant would be forced to move out, while those within a radius of 250 km of the plant, including Tokyo, would be allowed to leave if they wish.
“It contained such shocking content that we decided to treat it as if it never existed,” a senior government official said.
Another government source said, “When the document was presented, there was a discussion about the choice of keeping the existence of the document itself secret.”
Kan admitted the existence of a worst case scenario in September, while the government of his successor, Prime Minister Yoshihiko Noda, decided to treat the document as a Cabinet Office document after some parts of it were reported in December.
Gov’t kept Fukushima crisis worst-case scenario under wraps for months
Mainichi Daily News
Cabinet kept alarming nuke report secret
Japan Times
The government buried a worst-case scenario for the Fukushima nuclear crisis that was drafted last March and kept it under wraps until the end of last year, sources in the administration said Saturday.
After the document was shown to a small, select group of senior government officials at the prime minister’s office in late March, the administration of then Prime Minister Naoto Kan decided to quietly bury it, the sources said.
“When the document was presented (in March), a discussion ensued about keeping its existence secret,” a government source said.
In order to deny its existence, the government treated it as a personal document of Japan Atomic Energy Commission Chairman Shunsuke Kondo, who authored it, until the end of December, the sources said.
It was only then that it was actually recognized as an official government document, they said.
“The content was so shocking that we decided to treat it as if it didn’t exist,” a senior government official said.
A private-sector panel investigating the disaster at the Fukushima No. 1 nuclear plant intends to examine whether the government tried to manipulate information during its handling of the crisis.