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| Fig. 1: Fukushima nuclear accident. (Source: Wikimedia Commons) |
On March 11, 2011, the Fukushima Daiichi Accident occurred due to the tsunami following the Great East Japan Earthquake. [1] The earthquake in Miyagi hit a magnitude of 9.0 and was a double quake that lasted about three long minutes. [1] An area of the seafloor, about 650 km long, shifted about 10-20 meters horizontally. The tsunami resulted in about 19,000 deaths and damaged many towns, coastal ports and millions of buildings, truly revealing its intensity. [1] The earthquake knocked out offsite AC power to the plant and shut down its sustained fission reactors. Afterwards, the tsunami flooded parts of the plant site, resulting in disabled energy generators that would normally control the pumps that cool down the receivers. [1] These occurrences causing insufficient cooling resulted in three nuclear meltdowns and the release of radioactive material from Units 1, 2, and 3, hydrogen-air explosions, and the release of radioactive material causing contamination in Fukushima and other surrounding areas (see Fig. 1). [2] The severity of these disasters resulting in widespread evacuations of local population, and extreme distress and economic loss for the Japanese. [1]
After the earthquake and tsunami damaged the Fukushima nuclear power plan, Japan hadn't yet decided what to do with the million tons of radioactive water. [3] Some experts have advised the government to gradually release it in the Pacific Ocean, to make room in their storage tanks for radioactive water. [3] Over time, the treatment removed all the radioactive elements, excluding tritium. [2] Tritium is a radioactive form of hydrogen, due to its makeup of two neutrons, and is a relatively weak source of β radiation. [2] However, it can be a health risk if taken into the body directly in large quantities. According to the United Nations Scientific Committee for the Effects of Atomic Radiation (UNSCEAR) 2013 Report, the average dose of 25,000 workers 19 months after the incident was 12 mSv. Adults living in the area of Fukushima were estimated to receive and effective amount of 4 mSv (the effect of the radioactivity on the body is called radiation dose, and expressed in Sieverts (Sv) or millisierverts (mSv)). [4] To put the measurement in perspective, the average annual exposure in the region you'd receive naturally is 2.1 mSv. [4] This increased exposure to radiation due to the spill quantifies the health risks the incident posed to its people.
Michio Aoyama, a professor at the Institute of Environmental Radioactivity of Fukushima University, claims that the concentration of radiation, 0.02 becquerel per liter of seawater, is too little to affect the local fishing industry. [5] Although this is still up for debate, management strategies to address radioactive contamination on a higher scale haven't been established. [2] No high-level radioactive waste has been disposed of into the sea, but the health effects of these radioactive spills should be addressed and taken seriously.
© Melissa Lord. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] M. Edwards, "Stories From Experience: Using the Phenomenological Psychological Method to Understand the Needs of Victims of the Fukushima Nuclear Accident," Asian Perspec. 37, 615 (2013).
[2] T. A. Mousseau and A. P. Møller, "Nuclear Energy and Its Ecological Byproducts: Lessons from Chernobyl and Fukushima," Ch. 9 from Learning from Fukushima: Nuclear Power in East Asia, eds. P. Van Ness and M. Gurtov (ANU Press, 2017).
[3] D. P. Calmet, "Ocean Disposal of Radioactive Waste: Status Report," IAEA Bulletin, 1989.
[4] "Sources, Effects and Risks of Ionizing Radiation," UNSCEAR 2013 - Report the General Assembly with Scientific Annexes - Volume I, Scientific Annex A, United Nations Scientific Committee on the Effects of Atomic Radiation, 2014.
[5] S.-I. S. Matsuzaki et al., "Fukushima Disaster Indirectly Threatens Lake Ecosystems," Front. Ecol. Environ. 10, 464 (2012).
