Fukushima: Far More 'Chronic and Lasting' Cesium Contamination Than Previously Believed

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Common Dreams

Fukushima: Far More 'Chronic and Lasting' Cesium Contamination Than Previously Believed

by
Common Dreams staff

Workers begin pouring cement onto the seabed at the Fukushima No. 1 nuclear power plant on Feb. 28. (Eiji Hori)

A "mind-boggling" amount 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, 2011 meltdown, Japanese scientists said Wednesday.

Also, French scientists announced Tuesday that the amount of cesium released caused a chronic and lasting contamination of the environment. It was essential for Japan to maintain vigilant monitoring of fruit, milk, mushrooms, game and fish, they said.

According to the United States Geological Survey, it took only 18 days for the radioactive particles from Fukushima to circle the globe.

In Vermont, state officials have just confirmed finding trace amounts of Fukushima's cesium-134 and cesium-137. The state said they would continue the collection of samples from surface and drinking water, milk, vegetation and maple products.

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The Asahi Shimbun, Japan's leading daily newspaper, reports:

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.

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.

The researchers also estimated that 24-30 quadrillion becquerels of that cesium reached the sea.

That combines the roughly 70 percent of the total discharge, which is thought to have reached the ocean, and the cesium content of radioactive water that Tokyo Electric Power Co., the nuclear plant operator, released from the plant to the sea.

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The Agence-France Presse reports:

French Agency Calls Contamination at Fukushima 'Chronic and Lasting'

[...] “The initial contamination linked to the accident has greatly declined,” Didier Champion, crisis manager at the Institute for Radiological Protection and Nuclear Safety (IRSN), told reporters almost a year after the disaster.

“Today, and for many years to come, we will have a situation of chronic and lasting contamination of the environment.”

It was essential for Japan to maintain vigilant monitoring of fruit, milk, mushrooms, game and fish, Champion said.

“There are risks of chronic exposure at low dosage, and without care this can build up over time,” he warned.

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Meanwhile, across the globe in Vermont, the Brattleboro Reformer reports:

Fukushima Radioactivity Discovered in Samples Taken in Bennington

Measurements taken at the USGS’ Bennington National Atmospheric Deposition Program sampling station showed minute traces of radiological materials that were produced as a result of the disaster at the Fukushima nuclear power complex in Japan. [...]

"Explosions led to a month-long discharge of radioactive material into the atmosphere, which has since spread around the globe." According to the USGS, it is estimated that it took 18 days for the radioactive particles from Fukushima to circle the earth. USGS scientists detected iodine -131, cesium-134, and cesium-137, the primary radioactive products released during an incident such as Fukushima.

In Vermont, Cesium-134 was measured at .86 picocuries per liter and cesium-137 was measured at 3 picocuries per liter. No iodine was discovered in samples taken in Vermont. [...]

In its own sampling, the Vermont Department of Health used monitoring stations around Vermont Yankee nuclear power plant and an air sampling station in Burlington to measure the effects of Fukushima.

The reports are filed online at healthvermont.gov/enviro/rad/japan2011.aspx.

DOH, the Agency of Natural Resources and the Agency of Agriculture, Food & Markets are continuing the collection of samples from surface and drinking water, milk, vegetation and maple products.

Mark Nilles, a hydrologist with the USGS, said the levels detected at the NADP sampling station were very low.

"When that goes into the surface water supply it’s going to be diluted even further," he said. [...]

On March 11, 2011, a magnitude 9.0 earthquake centered off the Pacific Coast of Japan triggered a tsunami and a 14-meter tidal wave that inundated a large part of northern coastal Japan.

With the resulting massive flooding, the Fukushima Dai-ichi Nuclear Power Station was left without primary or backup electric power and thus cooling water, leading to catastrophic failure among its six nuclear reactors.

Subsequent explosions led to a month-long discharge of radioactive material into the atmosphere, which has since spread around the globe. According to the USGS, it is estimated that it took 18 days for the radioactive particles from Fukushima to circle the earth.

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