Wednesday, 18 September 2013

Introduction


The topic of nuclear energy is plagued with controversy. There have been 99 accidents that have taken place at nuclear powered power generation plants as stated in the Journal of Contemporary Asia which leads to my argument that making use of radioactive material to generate electricity by fission reaction is not suitable for Japan.
Anti-Nuclear Demonstration. Tokyo Japan
Japan is home to 50 reactors and while now thankfully all have been temporarily shut down following the Fukushima incident. It is likely only a matter of time before they become operational again.

My argument is not to broadly state that nuclear fission based energy production is a danger to our society. My argument is to show with reference that nuclear fission based energy production is not a good solution for Japan for the following reasons:

Seismic Activity and Tsunami Zone
The abundance of faults in Japan makes determining a suitable location for nuclear power generation a very difficult task.
Storage of Spent Fuel and Waste Material
The amount of spent fuel at nuclear power plants will soon exceed the available storage capacity.
Processing of Spent Fuel
Japan has a policy of re-processing spent fuel domestically, however they have to date been unsuccessful in their attempts.

Wednesday, 11 September 2013

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.




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.

Wednesday, 4 September 2013

Storage of Spent Fuel and Waste Material


When nuclear fuel is used in reactors it is still extremely dangerous for a very long time after the reaction has taken place. Plutonium 239 has a half-life of around 24,000 years, meaning that if exposed it would continue to pollute the environment for thousands of generations.


The amount of storage capacity for spent fuel at nuclear power plants will soon exceed the available storage capacity. As of 2006 it was expected that on site storage capacity would be exceeded in all reactors by 2015. With strict laws about where waste can be stored, what will happen to the waste?


When stored on site, fuel rods are kept cool by continuously running refrigerated water over them. These facilities are a constant expense and must be operational at all times. The dangers of storing such material are emphasised by the 2010 Fukushima incident in which cooling liquid leaked into the environment. The cost of storage is an issue for power companies, and driven by greed can lead to ineffective storage and control of where waste is kept.

Spent Fuel Cooling Pool


The town where I spent my exchange has just recently become the victim of contaminated waste dumping. This was on the bank of Japans largest lake with complete disregard for human life.

Dumped Cesium-Tainted Wood Chips, Lake Biwa, Japan

The fact that spent fuel and cooling waste must be kept out of the environment should be reason alone that using these kinds of materials to produce electricity is the wrong decision for Japan. This case shows how there can be such little regard placed on the safety of human life over money.