‘Mind-Boggling’: Scientists Say Far More Radioactive Cesium Released from Fukushima than Previously Thought – 40,000 Trillion Becquerels Estimated
By AKIKO OKAZAKI – “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.
The scientists measured cesium concentrations in seawater as of April and May last year. They then used a model of diffusion in the atmosphere and the oceans to evaluate the total amount of cesium released. The calculation produced estimates of 30-40 quadrillion becquerels.” Read more.
Tour of ‘fragile’ Fukushima nuclear plant shows shocking state of disrepair – “Japan’s tsunami-hit Fukushima power plant remains fragile nearly a year after it suffered multiple meltdowns, its chief said Tuesday, with makeshift equipment — some mended with tape — keeping crucial systems running. An independent report, meanwhile, revealed that the government downplayed the full danger in the days after the March 11 disaster and secretly considered evacuating Tokyo. Journalists given a tour of the Fukushima Dai-ichi plant on Tuesday, including a reporter from the Associated Press, saw crumpled trucks and equipment still lying on the ground. A power pylon that collapsed in the tsunami, cutting electricity to the plant’s vital cooling system and setting off the crisis, remained a mangled mess.” Read more.
Some parts of Tokyo now as contaminated as the worst area of Chernobyl – “The contamination level of Mizumoto Park turned out to be the same level of ‘off-limits zone’ in Chernobyl. The contamination level of the park was 23,300 Bq/Kg. According to Nuclear Safety Commission, it is converted to be 1.4 ~1.5 million Bq/m2. In Chernobyl, if the area is more contaminated than 1.48 million Bq/m2, it was labelled as off-limits zone, which was the worst level of the pollution. Because cesium doesn’t choose Mizumoto park intentionally, at least some parts are contaminated as the worst area of Chernobyl.” Read more.
Radioactive cesium in San Francisco-area milk now at 150% of EPA’s maximum limit – “The EPA Maximum Contaminant Level for radioactive cesium in milk is 3 picocuries/L: ‘EPA lumps these gamma and beta emitters together under one collective MCL [Maximum Contaminant Level], so if you’re seeing cesium-137 in your milk or water, the MCL is 3.0 picocuries per liter; if you’re seeing iodine-131, the MCL is 3.0; if you’re seeing cesium-137 and iodine-131, the MCL is still 3.0.’ … These are the highest cesium levels detected by UCB since at least August 2011 (As the MDA was higher over the summer, it’s hard to be sure of the exact levels at that time):” Read more.