As most of you well know, very recently there has been a series of natural disasters which has lead to the compromise and ended up with the malfunction of one of Japans nuclear reactors. Fukushima 1 nuclear reactor to be exact found itself in trouble when the 9.0 earthquake and tsunami disabled its cooling system. This eventually lead to the release of radiation. I would like to question if this release of radiation should be a serious source of concern and if the media has just been perpetuating fear in the public to get attention.
First off I will give some background information on the nuclear reactor itself. The boiling water reactor which was built in 1971 and located in the Futaba District of Fukushima Prefecture, Japan. The Fukushima 1 nuclear reactor is considered on of the 15 largest nuclear stations in the world and outputs a combined power of 4.7 GWe. In the past the power plant has already been a source of concern because it has been cited to be using outdated safety outlines, and had falsified inspection and repair reports. Luckily this pressure lead the company to build an emergency response center in 2010 which was used in the tsunami incident.
Next I would like to talk about what actually happened. On 11 March 2011 an earthquake and subsequent tsunami hit Japan. Units 4, 5 and 6 had already been shut down prior to the earthquake for planned maintenance. The remaining reactors were shut down automatically after the earthquake, and the remaining decay heat of the fuel was being cooled with power from emergency generators. The subsequent tsunami is the main cause of this disaster, because what it did was disable the emergency generators required to cool the reactors. A nuclear power plants generates electricity by heating fluid via a nuclear reaction to run a generator, and if the heat from that reaction is not removed a meltdown like the one seen here will occur. Even tough the units were shut down, the fuel was still emitting decay heat which can also cause a meltdown.
A meltdown of a nuclear reactor causes many concerns and one of the major one is the release of radiation which is a known cause of cancer. The question is, was the radiation released from this nuclear reactor enough to cause concerns? To first answer this question we must ask what is the acceptable amount a human body can tolerate? The U.S. Nuclear Regulatory Commission (NRC), sets an acceptable level of radiation exposure from any one source at 100 millirem a year. The average level of natural background radiation in the United States is about 350 millirem a year. A chest X-ray, for example gives the equivalent to 1 or 2 millirem to the whole body.
There has been many debates by scientist over what dose is acceptable and as we learned in class, really it is better to avoid radiation all-together seeing as how it damages our DNA. There has been debate about how much actual radiation has been released by this incident but one number that I found stated that at one point radiation levels reached 400 millisieverts an hour. (1 millirem=.01 millisievert). Because of so much debate on what level of radiation is acceptable by the human body and is able to be repaired, it has been hard to really make a statement on if the radiation released by this disaster should be a cause for concern. Looking at past events such as the Chernobyl disaster, and the Three Mile Island accident it tends to make me believe that the risk of cancer from exposure to these nuclear disasters is minimal. In both these past cases, cancer levels did not seem to rise, and the only form of solid cancer found was thyroid cancer. Because of this I believe that the media has greatly exaggerated the story. This does not mean that people should not take precautions, and that radiation at this level does not cause cancer because as we well know any amount of radiation could potentially lead to cancer.
Sources:
http://ecocentric.blogs.time.com/2011/03/13/japan-nuclear-emergency-how-much-radiation-is-safe/
http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant
http://en.wikipedia.org/wiki/Nuclear_meltdown
http://www.nytimes.com/2011/03/15/world/asia/15nuclear.html
http://news.nationalpost.com/2011/03/15/graphic-how-much-radiation-is-being-released-by-japans-runaway-reactors/
