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The Earthquake

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Illustration of the earthquake's epicenter

On Friday, March 11, 2011, a powerful magnitude 9.0 earthquake struck Japan; it was centered off the east coast of Japan's Honshu Island. This earthquake, and its resulting tsunami would go on to wreak havoc on Japan's nuclear power industry.

Why Does Japan Use Nuclear Power?

Japan is located along the Pacific Ring of Fire, a region of frequent and intense earthquake activity. Despite this, Japan had little choice but to construct nuclear power plants, as it has little coal or oil available for use. There are some rivers in the country that are dammed, but these hydroelectric dams produce only about 7% of the electricity Japan needs.

A Brief Description of the Power Plants

Fukushima I before...

...and after

The Fukushima nuclear power plants are two separate nuclear power plants located along the eastern coast of Honshu. These are the Fukushima Daiichi power plant (Fukushima I), with six reactors, and the Fukushima Daini power plant (Fukushima II), with four reactors.

Construction

Being in such an earthquake-prone area ensures there was a lot of data recorded about seismic activity in Japan. When the plants were originally designed, engineers noted that the most powerful earthquakes in the area were typically of magnitude 7 to 8. As the plants were built 40 years ago, knowledge of seismology during construction was far less as compared to today. However, through the years, with advances made in the knowledge of earthquakes, a corresponding update in the ability of the plants to withstand earthquakes and tsunamis failed to occur. In fact, the inital landscaping of the current power plant site actually increased risk of damage by tsunami. Originally, where Fukushima I now stands was a 35 metre high seaside cliff. However, TEPCO, the power company responsible for overseeing the plants reduced the height of that cliff to 10 metres. While the bedrock at that height would provide a sturdier base for the plant to lie on, the primary business reason for locating the plant at that height was the water pumps. They pumped water directly out of the ocean and up to the plant, for its use as a coolant in the reactors. Naturally, the lower the plant was built, the lower the operating costs of the pumps would be, despite the obvious increased tsunami risk. Actually, it would not be until 2006 that the Japanese government explicitly outlined the risks of tsunamis in its official regulations for nuclear power plants.

Concerns

TEPCO logo

Unlike BC Hydro, which is under the control of the provincial government, TEPCO was a private company. TEPCO had always claimed that their reactors were "absolutely failsafe", despite concerns that were raised by skeptical scientists. Alas, it appeared to be the political and business side of things that led into this disaster. In its dealings with the power companies such as TEPCO, the Japanese government was often seen as weak, and not forceful enough. In addition, Japan lacked one, central crisis management agency. Rather, there existed a process by which multiple people, such as the Prime Minister and the TEPCO director, decide how to manage a crisis. This leads to a fragmented leadership with the inability of effective decision-making.

Environmental Impacts

Of course, as with any serious nuclear accident, there will be effects on the environment; here those effects were largely due to the direct release of radioactive materials into the environment, by way methohds such as steam venting and power plant explosions. For example, seawater near the power plants was measured at 68 million Bq/m³ immediately after the accident. This high level of radiation was likely to the the large amount of ¹³⁷Cs that was released. Consider the impact that such a vast amount of radiation can have on marine life; there are a wide variety of organisms such as fish and plankton that could potentially intake this radiation. However, this uptake of radiation by fish also has an impact on humans. What happens to radioactive fish when they enter the human food supply? Fortunately, however, since the activities of radioactive material have been quickly decreasing since the incident, theoretical dose calculations would suggest that the seafood supply is not in immediate danger9. However, considering the short amount of time that had passed, the full effects of this incident on the ocean are probably not quite known yet. One of the components released into the atmosphere was cesium-137 (137Cs). This is a radioactive metal, with a half-life of about 30 years. Cesium is located within the first group of the periodic table, in the same column as potassium and sodium. As such, the human body considers it to be chemically similar to those elements, which could result in the absorption of radioactive materials into the human body. It is known that 137Cs was released into the atmosphere from this incident, however, estimates very as to how much cesium was actually released. Depending on the source, estimates can vary from 7.7 x 1017 Bq to 2.4 x 1018 Bq (5 to 17% the amount that was released in the Chernobyl disaster)10. As with Chernobyl, permanent evacuation of the area is the only solution if the land is deemed to be too radioactive. In Ukraine after the Chernobyl disaster, people living on land recorded to have radiation levels greater than 0.5 MBq/m2 were forcibly resettled. In the aftermath of the Fukushima disaster, a radiation level of 3.7 MBq/m2 was noted on some lands near the power plants11. So, the long-term solution appears to be similar to the one imposed after Chernobyl: permanent evacuation and resettlement from lands that are deemed inhabitable.

Impacts on Nuclear Power in Other Regions

After the Fukushima incident, questions about nuclear power in other countries were raised. For example, immediately after the Fukushima accident, the German government announced that it would immediately shut down its oldest nuclear reactors. This would be followed by the gradual decommissioning of all remaining nuclear power plants in Germany over the next 10 years. Considering that nuclear power was responsible for 29% of Germany’s electricity production12, this will leave a huge gap to be filled for Germany’s future power needs. This is an exceptionally strong reaction, considering the differences between the geography of Germany and Japan. Japan, which is located at the intersection of the North American, Eurasian, and Philippine plates, is very prone to earthquake activity due to the presence of those fault lines. On the other hand, Germany is located far away from any major fault lines, and is thus far less earthquake-prone than Japan. Thus, although fears of nuclear power in Germany were awoken after the Fukushima incident, the difference in geographies of the two countries presents two very different scenarios. Instead, it was noted that without nuclear power, Germany’s economy could suffer, due to switching from an electricity exporter to an electricity importer12. Another country potentially impacted by this disaster is Taiwan. Taiwan, like Japan, is located along the Pacific Ring of Fire, and also suffers from frequent earthquakes. Taiwan has three active power plants, and one under construction, all of which, like Fukushima, are located along the coastline. Much like the Japanese government prior to the Fukushima incident, the Taiwanese government tried to deny that such a disaster could ever take place in Taiwan. However, a report made by the World Nuclear Association revealed that it had named all of four of Taiwan’s nuclear power plants among the top 14 most dangerous plants in the world13. After Fukushima, there were many protests demanding that the government shut down the power plants in order to prevent a similar disaster in Taiwan. However, in the end, unlike Germany, Taiwan did not shut down any reactors, and construction of the fourth power plant remains ongoing. This is a risky move, as the world has seen what can happen when nuclear power plants are not built strong enough to withstand powerful earthquakes and tsunamis.

References

1. Ramseyer, J.M. Theoretical Inquiries in Law. 2012, 13(2) (To be published)
2. Onishi, N.; Glanz, J. Japanese Rules for Nuclear Plants Relied on Old Science, The New York Times, March 26, 2011.
3. Yoshida, R.; Fukada, F. Fukushima plant site originally was a hill safe from tsunami, The Japan Times, July 12, 2011.