By Akiko Okazaki / The Asahi Shimbun / February 29, 2012 /
A mind-boggling 40,000 trillion becquerels of radioactive cesium, or twice the amount previously thought, may have spewed from the crippled Fukushima No. 1 nuclear power plant after the March 11 disaster, scientists say.
Michio Aoyama, a senior researcher at the Meteorological Research Institute, released the finding at a scientific symposium in Tsukuba, Ibaraki Prefecture, on Feb. 28.
The figure, which represents about 20 percent of the discharge during the 1986 Chernobyl nuclear disaster, is twice as large as previous estimates by research institutions both in Japan and overseas.
It was calculated on the basis of radioactive content of seawater sampled at 79 locations in the north Pacific and is thought to more accurately reflect reality than previous simulation results.
Scientists believe that around 30 percent of the radioactive substances discharged during the crisis ended up on land, while the rest fell on the sea.
This makes it especially difficult to accurately evaluate the total amount of radioactive materials released. Thus, seaborne data is essential to the process.