A Japanese government panel investigating last year's meltdown of three reactors at Japan's Fukushima Dai-ichi nuclear plant says Tokyo Electric Power officials ignored the risks of a nuclear accident because they believed in what the report called the “myth of nuclear safety.”

The report, issued Monday, said TEPCO and Japan's Nuclear and Industrial Safety Agency were not prepared to cope with a tsunami and severe accidents.

Tens of thousands of people rallied in Tokyo last Monday to protest the use of nuclear power, highlighting the growing opposition to atomic energy in Japan since the crisis at the Fukushima power plant.