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| Fig. 1: Aerial view of exploded Units of Fukushima Nuclear Reactor. (Source: Wikimedia Commons) |
The Fukushima Daiichi nuclear accident occurred in northern Japan, and is widely regarded as the second worst nuclear accident in the nuclear power generations history. [1] It was caused by a tsunami (estimated to be 45 feet tall), which was due to the Tohoku earthquake on March 11; a pair of natural disasters that shut down the power and cooling of three nuclear reactors, leading to three nuclear meltdowns, and hydrogen air explosions. [2] All three reactors mostly melted within three days, while a fourth was damaged (see Fig. 1).
The way a nuclear power plan operates involves steam being used to produce energy. The steam is created through nuclear fission, splitting an atom in two to create this energy. The atom thats being split is metal uranium, with the enriched uranium that is produced from the fission placed into thin rods that are coated with zirconium. [2]
The Tohoku earthquake, which measured at a magnitude of 9.0, forced the Fukushima Daiichi power station to go into shutdown. [2] The ensuing tsunami disabled the power panels in the plant, meaning the cooling systems werent able to be restarted. This led to the hot rods to boil the water into steam, with the temperature in the reactor units rising at an immense rate. The temperature inside the vessel reached 1300°C, which, combined with the zirconium coating on the rods, produced a dangerous form of hydrogen gas. [3] Around 24 hours after the earthquake hit, the hydrogen that was being created rose to the ceiling of Unit 1, leading to a spark that led to the reactor exploding. [1] This turned Fukushima into a radioactive hot zone, and created an environment that was volatile enough to lead to the explosion of both Unit 3, then Unit 4 (see Fig. 1). The Fukushima disaster is estimated to have caused 573 fatalities, and as the radioactive material created a "danger zone" with a 20 km radius, changed the lives of many more. [4]
To this day, the Fukushima nuclear power plant disaster is considered one of the worst disasters in the nuclear power generations history. [1] Despite the evacuation order being released, health records of ex-workers at the plant are displaying quite a causal relationship between the disaster and cancer. Hopefully this disaster can be used for good, and serve as a clear warning for power plants worldwide, who may be encouraged to take precautions which can reduce the likelihood of the reoccurrence of such a disaster.
© KZ Okpala. 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.
[1] K. Kurokawa et al., "The Fukushima Nuclear Accident Independent Investigation Commission: Executive Summary," National Diet of Japan, 2012.
[2] V. Lakhlani, "Natural Disaster and Safety in the Nuclear Industry - Fukushima Accident," Physics 241, Stanford University, Winter 2018.
[3] J. P. Christodouleas et al., "Short-Term and Long-Term Health Risks of Nuclear-Power-Plant Accidents," New Engl. J. Med. 364, 2334 (2011).
[4] A. Trinh, "Fukushima Daiichi Nuclear Power Station Disaster," Physics 241, Stanford University, Winter 2018.
