Radiation From Fukushima Accident Revised Up In New Report

CNN.com reports here:

Japan's largest utility said Thursday that more radiation than previously thought was released into the atmosphere in March 2011, in the days after the nuclear disaster that followed an earthquake and tsunami. TEPCO (Tokyo Electric Power Co.) estimates about 900,000 terabecquerels of radioactive materials were released between March 12 and March 31, according to Japan's Kyodo news agency. ... In one town in the Fukushima area, the estimated thyroid doses to infants are within a dose band of 100 to 200 millisieverts (mSv), the preliminary report said. This level of radiation exposure could be associated with an increased likelihood of developing cancer. However, in the rest of Japan, the estimated thyroid doses are within a dose band of 1 to 10 mSv, the report said. Outside the country, the estimated thyroid doses are less than 0.01 mSv, and are usually far below this very low level, it said.

PBS.org had a fuller report here, comparing the accident's severity to Chernobyl and assessing the health consequences of the radiation releases:

Tokyo Electric, the plant’s operator, said on Thursday that reactor meltdowns at the Fukushima Daiichi plant released approximately 900,000 terabecquerels of radioactive substances into the air in the immediate aftermath of the March 2011 accident. By comparison, approximately 5.2 million terabecquerels of total radiation were emitted in the 1986 Chernobyl disaster. ... In terms of the accident’s health implications, the World Health Organization said on Wednesday that the amount of radiation released fell below cancer-causing levels in nearly all of Japan. Outside of “no-go zones” in Fukushima prefecture, residents were exposed to radiation levels between 1 millisievert and 10 millisieverts, the W.H.O. said. The annual average amount of exposure from naturally occurring background radiation is 2.4 mSv globally, according to the report ... . Cumulative exposure to 100 mSv is generally thought to raise a person’s risk of cancer death by 0.5 percent.

Reuters.com reports here that Namie and Iitate were the two towns hardest hit:

In a preliminary report, independent experts said that people in two locations in Fukushima prefecture may have received a radiation dose of 10-50 millisieverts (mSv) in the year after the accident at the power station operated by TEPCO. ... The areas estimated to have received the highest doses of radiation were Namie town in Futaba county and Iitate village in Soma county, northwest of the stricken plant, the report said. Infants in Namie were thought to have received thyroid radiation doses of 100-200 mSv, it added. The thyroid is the most exposed organ as radioactive iodine concentrates there and children are deemed especially vulnerable.

Follow the labels at the end of this post for this blog's reporting on the accident from the beginning.

Fukushima Accident Summary From World-Nuclear.org

When the data differ, the on-going summary defers provisionally to the Japanese regulator.

Here is an excerpt dealing with the apparent rupture of the suppression chamber of reactor 2 on March 15 after its cooling power failed on the 14th and its water in the torus boiled.

From the "Fukushima Accident 2011" at World-Nuclear.org, last updated today (here):

After the hydrogen explosion in unit 1, some radioactive caesium and iodine were detected in the vicinity of the plant, indicating fuel damage. This material had been released via the venting.  Further I-131 and Cs-137 and Cs-134 were apparently released during the following two weeks, particularly following the apparent rupture of suppression chamber of unit 2 on 15th. The caesium was at low levels (about two orders of magnitude less than the iodine). The hydrogen explosion in unit 4 involving the spent fuel pond on 15th apparently added to the airborne radionuclide releases.

Namie, Japan, Radiation 14 Millisieverts in 17 Days, In Iitate 8 Millisieverts

The source is believed to be cesium, with a very long half-life (a generation) compared to radioactive iodine (a week).

An American gets on average 6.2 millisieverts in a year from all sources. Japanese set the threshold for natural sources at 1 millisievert.

NHK World has the story here:

Since March 23rd, the ministry has been measuring radiation levels in 15 locations more than 20 kilometers away from the crippled Fukushima Daiichi nuclear power plant.

At one location, in Namie Town about 30 kilometers northwest of the plant, 14,480 microsieverts of radiation had accumulated over the 17-day period to Sunday.

8,440 microsieverts of radiation were observed in Iitate Village.

In another location in Namie, the amount reached 6,430 microsieverts.

People would be exposed to this accumulated amount of radiation if they had stayed outdoors throughout the entire period.

Iodine 131 and Xenon 133 Show Up in Nevada

As reported here:

[E]xtremely small amounts of iodine-131 and xenon-133, both of which are not usually found in Nevada, were detected at a monitoring station near the Atomic Testing Museum in the city following a series of radiation leaks at the Fukushima Daiichi plant.

Fukushima Reactor 2 Basement Puddle Emitting 1000 mSv/hour

An astounding number, which amounts to 1 Sievert per hour, from a puddle.

Half of that is 500 mSv/hour, previously reported in the air over one of the reactors. That's the amount in a hour an American can expect to absorb in a life. Now double that, in an hour.

Just two hours exposed to radiation at 1 Sievert per hour is sometimes fatal, while 8 Sieverts is most definitely fatal. Chernobyl threw off 50 Sieverts near the destroyed core in just ten minutes.

The report comes from Kyodo News today, here:

The concentration level is 10 million times higher than that seen usually in water in a reactor core, according to plant operator Tokyo Electric Power Co.  Hidehiko Nishiyama, spokesman for the government's nuclear safety agency, said the figure is ''quite high'' and ''likely to be coming from the reactor.'' ...

The radioactivity at the surface of the puddle at the No. 3 unit was 400 millisieverts per hour. ...

According to the latest data released Sunday, radioactive iodine-134, a substance which sees its radiation release reduced to about half in some 53 minutes, existed in water at the No. 2 reactor's turbine building at an extremely high concentration of 2.9 billion becquerels per 1 cubic centimeter.

The water also contained such substances as iodine-131 and cesium-137, known as products of nuclear fission, and thus leading to speculation that it may have come through pipes that connect the reactor vessel and turbines, where steam from the reactor is normally directed to for electricity generation.

The pool of water at the No. 4 reactor's turbine building included radioactive substances, but the concentration level was not as high as at the Nos. 1, 2 and 3 buildings, the data showed.

TEPCO Speculates Radioactive Puddle Contents Are Sign of Reactor Breach

NHK World has the story here about the puddle which injured 2 workers, exposing them to over 170 millisieverts while laying cable near the reactor 3 turbine room:

The level of radioactive cerium-144 was 2.2 million becquerels. Also, 1.2 million becquerels of iodine-131 was measured. These substances are generated during nuclear fission inside a reactor.

Tokyo Electric says damage to the No.3 reactor and spent nuclear fuel rods in a storage pool may have produced the highly radioactive water.

Iodine 131, Cesium 134, Cesium 137, Cobalt 58 All Found in Sea Water Near Fukushima

As reported here:

According to TEPCO, radioactive iodine-131 was detected Monday in the seawater samples at levels 126.7 times higher than the legal concentration limit. Levels of cesium-134 were 24.8 times higher and those of cesium-137 16.5 times higher while a trace amount of cobalt 58 was detected in a sample of seawater taken from near the plant.

Radiation in Perspective

Over the course of an average American life of 78 years, cumulative normal overall radiation exposure of 6.2 millisieverts annually amounts to about 484 millisieverts in a lifetime. Expressed in microsieverts, 6,200 annually amounts to 483,600 microsieverts in a lifetime.

The Wall Street Journal reports here about current radiation conditions in Fukushima City, 60 miles from the damaged reactors on the Japanese coast:

At Fukushima City, 60 miles from the plant, the recorded amount of radiation on Thursday was 20 microsieverts per hour, a level that is roughly 1,000 times higher than in Japanese cities far from the plant. Still, scientists say it isn't enough to cause long-term health effects.

Officials at Fukushima City also said that they found iodine, cesium-135 and cesium-137 in drinking water, at about one-quarter the levels that would make the water unfit to drink.

If the rate of 20 microsieverts per hour persisted indefinitely, it would take just 2.76 years for a resident of Fukushima to absorb what under normal conditions an American might expect to be exposed to in a lifetime: 483,600 microsieverts.

Expressed in millisieverts, the present rate of exposure 60 miles away is the equivalent of 175.2 millisieverts per year. Normal in America would be 6.2 millisieverts per year. So over the course of a lifetime, that's about 13,666 millisieverts for residents of Fukushima, 54 times above what is normal in America. The cumulative one time exposure limit for an emergency worker is 250 millisieverts, which is reported to be the amount radiated HOURLY above Fukushima I, reactor 3.

"Scientists say it isn't enough to cause long-term health effects" in this context is completely unbelievable.

Are they just saying this stuff to keep a lid on the anger which is threatening to boil over?

Just remember, it's all in the name of mere electricity.