The Fukushima nuclear disaster in Japan was caused by authorities "choosing to ignore risks and make business a higher priority than safety," Greenpeace claimed in a new report released on Tuesday.
The Lessons from Fukushima study was put together by nuclear physicist Dr David Boilley, Japan correspondent for The Chronicle of Higher Education Dr David McNeill and Arnie Gundersen, a nuclear engineer with Fairewinds Associates.
It was peer reviewed by Dr Helmut Hirsch, a scientific consultant on nuclear safety.
The experts contend that Japanese authorities and the private firm that owned and operated the Fukushima plant were "entirely wrong" in their assumptions about the risks of a serious accident, and that real risks were known but downplayed.
The report notes that hundreds of thousands of people made homeless by radioactive contamination cannot rebuild their lives due to a lack of support and financial compensation and predicts that Japanese taxpayers will end up shouldering most of the financial burden.
Greenpeace activist Jan Vande Putte warned that the "human-made nuclear disaster" could be repeated at any nuclear plant in the world, putting millions at risk.
He said: "While triggered by the tragic March 11 earthquake and tsunami, the Fukushima disaster was ultimately caused by the Japanese authorities choosing to ignore risks, and make business a higher priority than safety."
Japanese authorities announced in December that the Fukushima facility is stable and "minimal" radiation is being released from its melted reactors.
But plant chief Takeshi Takahashi conceded on Tuesday that the plant is still in a "fragile" condition.