A team of experts from the International Atomic Energy Agency (IAEA) said in their summary of a draft report on Japan's nuclear crisis that authorities underestimated tsunami risks and called for independent nuclear regulatory authorities, news reports said Wednesday.
The 18-member team, led by Mike Weightman, the head of Britain's Nuclear Regulation Office, was expected to submit the summary to the Japanese government later in the day as they conclude their 10-day investigation into the world's worst nuclear crisis in 25 years, dpa reported.
The Fukushima Daiichi nuclear plant was crippled by a magnitude-9 earthquake and tsunami on March 11 and it has leaked radioactive substances ever since.
The draft said that the danger of tsunami was "apparently underestimated" by the government and plant operator Tokyo Electric Power Co.
Nuclear designers and operators should appropriately evaluate the risks of all natural hazards and "periodically update these assessment methodologies" in light of information and experience, Kyodo News reported citing unnamed sources familiar with the report.
The plant was damaged by tsunami waves more than 14 metres high.
The IAEA team also stressed the importance of "regulatory independence." Japan's Nuclear and Industrial Safety Agency is part of the Industry Ministry, whose job is to promote nuclear power generation, leading to potential conflicts of interest.
The experts positively evaluated Japan's response to the nuclear crisis at the plant as "exemplary" while noting the need to look into the danger posed by hydrogen, which led to blasts at reactors 1 and 3 in the early days of the crisis, Kyodo reported.
The IAEA team was scheduled to present its report at a ministerial meeting on nuclear safety to be hosted by the IAEA in Vienna later this month.