A group of about 50 workers was eventually able to bring the plant under control.
TEPCO, which declined to take part in the investigation, has denied it planned to abandon Fukushima Dai-ichi. The report notes the denial, but says Kan and other officials had the clear understanding that TEPCO had asked to leave.
But the report criticizes Kan for attempting to micromanage the disaster and for not releasing critical information on radiation leaks, thereby creating widespread distrust of the government.
Kan said he was grateful the report gave a favorable assessment of his decision to prevent TEPCO workers from abandoning the plant.
"I give my heartfelt respects to the efforts of the commission," he said in a statement. "I want to do my utmost to prevent a recurrence."
Kan has acknowledged in a recent interview with AP that the release of information was sometimes slow and at times wrong. He blamed a lack of reliable data at the time and denied the government hid such information from the public.
The report also concludes that government oversight of nuclear plant safety had been inadequate, ignoring the risk of tsunami and the need for plant design renovations, and instead clinging to a "myth of safety."
"The idea of upgrading a plant was taboo," said Koichi Kitazawa, a scholar who heads the commission that prepared the report. "We were just lucky that Japan was able to avoid the worst-case scenario. But there is no guarantee this kind of luck will prevail next time."
Associated Press writer Yuri Kageyama contributed to this report from Tokyo. Follow Yamaguchi at http://twitter.com/mariyamaguchi and Kageyama at http://twitter.com/yurikageyama
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.