Seismic Activity and Tsunami Zone

It is very unwise to operate fission reactors given that Japan is such an active earthquake and tsunami zone. Japan is a literal jigsaw puzzle of fault lines meaning that maintaining safe operation is at the whim of nature. Japan has two significant faults running through it. The Japan Median Tectonic Line 中央構造線 being the largest, however there are in fact 9 faults.

Niigata/ Kobe Tectonic Zone

Nobel Prize winning physicist Hannes Alfvén stated.

“Fission energy is safe only if a number of critical devices work as they should … No acts of God can be permitted.”

Meaning that when dealing with nuclear reactions, there are situations which may arise beyond our control. 

Due to excessive ground acceleration over the past 10 years Japanese reactors were forced to shut down 5 times. Starting in 2004, 2005, 2007, 2009 and most recently in March 2011 when the Touhoku earthquake and tsunami hit Japan.

Before 1995 Nuclear power plants were designed to withstand a peak ground acceleration (PGA) of level S1, which was the largest earthquake which was thought to be reasonable expected to occur in the area based on historical seismic activity. PGA S2 equated to a 6.5 magnitude earthquake.

In 1995 there was a magnitude 7.2 earthquake in Kobe, and again a 7.3 magnitude earthquake in 2000. This shows the unpredictability of earthquakes, and the lack of understanding of where faults exist in Japan.

The five Fukushima reactors were designed in the 1960’s and had an extremely low safety margin when compared to the more recently developed standards for “safer” operation in Japan that exist today. Fukushima was designed to operate with 8 hour battery reserves, that as it turned out were not enough to cope with the significant damage caused by earthquakes and resulting tsunamis in March 2011.

The volatile faults under Fukushima have resulted in more than 24,000 aftershocks. This activity has reactivated yet another dormant fault under Japan. With aftershocks as strong as 7.0 there is still significant danger posed by the crippled reactors. The history of violent seismic activity in Japan is clearly a significant reason that Nuclear reactors should not be operated. Nature cannot be controlled. And it is clear that these “Acts of God” are beyond the control of the designers of these facilities.

To further add to the argument that faults are completely unpredictable. A recent geological survey has determined that an active fault is directly under the Tsuruga atomic station. 

Tsuruga Atomic Station

Japan having such a plethora of faults is most definitely a poor choice for the location of nuclear energy plants. As shown by the recent discovery in the Nuclear Regulation Authority survey (above) not enough is known to even try to mitigate the significant risk posed.