After the Japanese government was presented with a worst-case scenario by Japan Atomic Energy Commission Chairman Shunsuke Kondo in the aftermath of the Fukushima disaster, they kept the report secret because "it was so shocking" and would frighten the public, according to a report from Kyodo news.
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.
Goshi Hosono, the nuclear crisis minister, said earlier this month that the public wasn't informed of the content of the scenario over fears it "would cause unnecessary anxiety."
Tokyo Electric Power Company (Tepco) recently recently video from an endoscope pushed into one of the reactors at Fukushima: