The International Atomic Energy Agency criticized Tokyo Electric Power Co. and Japanese regulatory authorities for their failure to prevent the 2011 Fukushima No. 1 nuclear plant disaster despite knowing the risk of large tsunami hitting the facility, according to a copy of an IAEA report.

The U.N. nuclear watchdog said in the final report on the nuclear disaster triggered by a huge earthquake and tsunami in March 2011, obtained Sunday, that "the Fukushima Daiichi (No. 1) NPP (nuclear power plant) had some weaknesses which were not fully evaluated by a probabilistic safety assessment, as recommended by the IAEA safety standards."

The paper, compiled by around 180 experts from 42 countries, is set to be submitted to the IAEA's annual meeting in September after its board examines the 240-page summary in June.