June 7, 2011

Japan Radiation Leaks Double Previous Estimates

A report from the Japanese government to the International Atomic Energy Agency (IAEA) details that officials were unprepared for a nuclear accident on the scale of the one at the Fukushima plant, BBC News reports. 

The report highlights that poor oversight may also have contributed to the crisis.

Authorities have pledged to make the country's nuclear regulator (NISA) independent of the industry ministry, which also promotes nuclear power. This report comes after NISA doubled its initial estimate of leaked radiation in the first week after the disaster.

The nuclear safety agency now says 770,000 terabecquerels escaped into the atmosphere following the tsunami and subsequent explosion at the nuclear power plant - more than double its earlier estimate of 370,000 terabecquerels.

Although the amount is just 15% of the total released at Chernobyl in Ukraine in 1986, it suggests the contamination of the area around the plant is worse than first thought.

Yotaro Hatamura, a Tokyo University researcher on human error and a member of an independent 10-member academic and expert panel, said at the meeting that "nuclear power has higher energy density and is dangerous. It was a mistake to consider it safe", AFP reports.

Experts stress that the majority of the radiation released in the first days after the quake, was blown across the Pacific Ocean, not over inhabited areas.

Prime Minister Naoto Kan's special advisor on the nuclear crisis, Goshi Hosono, said he still wishes to see all reactors brought to a stable "cold shutdown" by October-January.

Much of the nuclear fuel inside the three reactors, NISA believes, melted faster than previously estimated after the plant's cooling systems were knocked offline by the tsunami. The agency said melted fuel in unit one dropped to the bottom of the pressure vessel and damaged it some five hours after the quake hit the plant on March 11, followed by a 46-foot wall of ocean water.

Tokyo Electric Power Company (TEPCO), believes the molten fuel rods are now being cooled by water at the bottom of the number one, two and three reactor pressure vessels, citing the relatively low outside temperatures of the containers.

Months of hosing operations have left over 100,000 tons of highly radioactive water in buildings, basements and tunnels at the plant, and TEPCO is struggling to remove the runoff so it can resume crucial repair work.


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