The Fukushima Nuclear Disaster
On March 11, 2011 in Japan a 9.0 magnitude earthquake struck. The quaking of the ground causes the three reactors of the Fukushima Daiichi nuclear power plant to commence an automatic shutdown of their operations. About one hour later the city is again hit but this time by a 14 meter tsunami triggered by the preceding earthquake. More than 10,000 people were killed in the natural disaster. The following events lead to one of the greatest nuclear disasters caused by natural disasters.
The tsunami disabled AC power to Units 1, 2, and 3. Along with the waters of the tsunami went the fuel tanks which were required for the operation of the emergency diesel generators. A series of water injection and cooling system fails and hydrogen explosions results in damages to Units 1 through 4. These failures and damages allowed large amounts of radioactive materials to be released into the environment.
Radiation
According to the World Nuclear Association, during ventilation of two of the units, the radionuclides caesium and iodine were released and later found in areas surrounding the power plant. The hydrogen explosion sparked a release of even more radioactives on and weeks after the disaster occurred.
Used radiation suits used in the wake of the disaster
One week after the Fukushima disaster, the Japanese Nuclear Safety Commission advised an evacuation of people under 40 years old within a 20km radius of the power plant. Their suggestion was based on worry about children ingesting radioactive iodine-131 through milk or some other way.
In the evacuation zone, tests revealed contamination from caesium-137 which has a 30 year half-life and also the iodine-131 which has an 8 day half-life.
This chart shows ionizing radiation doses and the effects of that radiation/equivalency.
| Dose (mSv) | Effect |
| 0.1–0.3 | chest X-ray |
| 3–4 | world average dose per year of exposure to radiation |
| 0.6–2.7 | stomach radiography |
| 7–20 | CT scan |
| 50 | dose limit per year among radiation workers |
| 200 | lifetime exposure to natural radiation |
| 500 | decrease in lymphocytes, cataracts |
| 1000 | acute radiation damage, nausea, vomiting |
| 2000 | 5% of those exposed die within several weeks |
| 3000–5000 | 50% of those exposed die within several weeks |
| 7000–10000 | 95% of those exposed die within several weeks |
| 20000–60000 | cerebral edema, respiratory distress, diarrhea, fever, circulatory failure within 1–2 weeks |
| 100000 | instant coma, death within hours |
After the disaster, most expected radiation injury to be rampant among civilians. However, none suffered from acute radiation injury: full-body exposure to high dosages of radiation resulting in sever bodily damage. But the long-lasting effects of radiation exposure after the crisis will be revealed through late radiation injury: full-body exposure to low doses of radiation. Effects usually take several years/decades to appear. Typical sicknesses that result from this are leukemia and cataracts. It is late radiation injury which many Japanese people are concerned about and waiting to see how their future health will fare.
After the disaster there were about 160,000 evacuees displaced from their homes. Many evacuees were sent to places such as auditoriums and other large facilities which could house large numbers of people. Radiation screens were pre-requisites for entering into facilities. Many families were separated as a result of differing toxicity levels and consequently housed separately.
More images from the Fukushima Nuclear Disaster
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References
HOSAKA, TOMOKO A. and SHINO YUASA. “Japan Earthquake And Tsunami Death Toll Exceeds 10,000.” Huffington Post. (2011). Web. <http://www.huffingtonpost.com/2011/03/25/japan-death-toll-earthquake-tsunami_n_840435.html>.
Kazunori , Anzai, Nobuhiko Ban, Toshihiko Ozawa, and Shinji Tokonami. “Journal of Clinical Biochemistry and Nutrition.” Journal of Clinical Biochemistry and Nutrition. 50.1 (2011): 2-8. Print. doi: 10.3164/jcbn.D-11-00021
“Fukushima Accident 2011.” World Nuclear Association. (2011). Web. <http://www.world-nuclear.org/info/fukushima_accident_inf129.html>.
Chart
Kazunori , Anzai, Nobuhiko Ban, Toshihiko Ozawa, and Shinji Tokonami. “Journal of Clinical Biochemistry and Nutrition.” Journal of Clinical Biochemistry and Nutrition. 50.1 (2011): 2-8. Print. doi: 10.3164/jcbn.D-11-00021
Image URLs
http://news.nationalgeographic.com/news/2011/03/pictures/110315-nuclear-reactor-japan-tsunami-earthquake-world-photos-meltdown/
http://www.cbsnews.com/8301-503543_162-20042270-503543/japan-earthquake-how-big-was-it-/
http://www.businessweek.com/news/2012-03-05/children-of-fukushima-wait-for-un-radiation-study
http://news.nationalgeographic.com/news/energy/2011/11/pictures/111111-nuclear-cleanup-struggle-at-fukushima/
http://nige.wordpress.com/2011/03/12/the-explosion-on-12-march-2011-of-the-outer-concrete-containment-building-of-japans-fukushima-dai-ichi-nuclear-reactor-number-1/
http://journeys4good.com/on-location/fukushima-50-japans-volunteer-heroes-and-the-international-volunteers-they-inspire/
http://www.news.com.au/world-old/magnitude-quake-strikes-japan/story-e6frfkyi-1226022184537
http://www.earthquakejapan2011.com/
alethea11
November 10, 2012 - 9:25 pm
The radiation chart and photos were a great addition to the post!