Cleanup After the Fukushima Disaster

Helen Liu
March 22, 2018

Submitted as coursework for PH241, Stanford University, Winter 2018

Background

Fig. 1: Assembly of Hose Fitting for Fukushima complex - work done to cleanup after the Fukushima Accident. (Courtesy of the U.S. Department of Defense. Source: Wikimedia Commons)

On March 11, 2011, after a magnitude 9 earthquake hit Japan, a 15 meter tsunami resulted in the melting of the Fukushima Daiichi reactors. Eleven reactors at the four nuclear power plants in this region were all shut down after the earthquake but the main damage was due to the tsunami. The tsunami flooded the site and led to the malfunctionary cooling and water circulation. [1] This incident has been the largest civilian nuclear accident since the Chernobyl accident and over 100,000 people were evacuated. [2] The International Nuclear and Radiological Event Scale (INES) rated the accident 7, the highest level. According to the official report of the Fukushima Nuclear Accident Report, "approximately 9 × 1015 Bq of radioactive substances have been released since March 11, affecting around 1800 square kilometers of land in Japan with varying levels of radiation." [3]

Government Response

Japan evacuated almost 19,000 residents within a 12.5 mile radius of the facility immediately. [1] However, the vast majority of evacuated residents are yet to return to their homes despite seven years later. [2]

Cleanup

Fig. 2: Diagram of radioactive water removal through a gravel layer. (Source: Wikimedia Commons)

Almost seven years after the accident, the Japanese government is still committed to the grueling cleanup of Fukushima (Fig. 1). Around 1,500 fuel rods were successfully removed in 2014. Radiation levels are controlled and lots of contamination in the site has been cleared. [4] Most of the dangerous tasks are still yet to be completed. It is estimated that cleanup will take at least 40 years. There are 7,000 workers currently. Workers keep radioactive water from flowing through the damaged reactor cores and must pump out about 720 tons of water from the basements every day into man-made tanks (Fig. 2). These tanks are kept in buildings which some workers currently are constructing around the plant. The plant also releases 2,000 tons of groundwater into the ocean every week after a process to remove most of the radioactive particles. [4] The method for cleanup of the damaged reactor cores is still to be determined.

The Future of Japan's Nuclear Power Industry

Cleanup workers are regulated by the government not to be exposed to too much radiation and workers frequently calculate how to keep their exposure levels low not for health reasons but because if laid off, they risk unemployment or lower-paying jobs. [4] The government is also worried about the negative consequences it has on the industry. Clean up is causing labor shortages and due to the shrinking population, many Japanese people are unwilling to find employment in the nuclear power industry. Even though Japan plans for nuclear power to contribute 20-22% of electricity, it is unclear how the industry will turn out. [5]

© Helen Liu. 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.

References

[1] I. Sample, "Japan's Nuclear Crisis: The Causes and the Risks," The Guardian, 13 Mar 11.

[2] J. McCurry, "Dying Robots and Failing Hope: Fukushima Clean-Up Falters Six Years After Tsunami," The Guardian, 8 Mar 17.

[3] A. Barr, "Fukushima: A Comparison to Other Nuclear Accidents," Physics 241, Stanford University, Winter 2015.

[4] J. Soble, "Fukushima Keeps Fighting Radioactive Tide 5 Years After Disaster," New York Times, 10 Mar 16.

[5] J. Sao, "The Evolution of Nuclear Energy in Japan and Germany," Physics 241, Stanford University, Winter 2017.