The 1986 Chernobyl accident in Ukraine, the Three-Mile Island Unit 2 melt down in 1979 in Middletown USA, and the Japan’s Fukushima nuclear disaster in 2011 count as the three most serious nuclear disasters in the history. The occurrence of had immediate as well as long-term effects to the economies, environment as well as peoples’ lives in those countries. In this paper, a detailed comparison of the three incidences will be carried out with special emphasis on their causes and the short-term as well as long effects.
Chernobyl nuclear accident
The 1986 incidence is considered as an accident that resulted out of a power surge that lead to the explosion of the unit 4 of the nuclear power station in Chernobyl, Ukraine. It is believed that the main cause of the accident was human errors as well as flaws in the design of the reactor. According to the Nuclear Energy institute, the cause of the accident is believed to have as a result of workers operating the reactor in violation of the technical specifications. The reactor was run at very low power without observing the safety precautions. The four reactors in Chernobyl were the high-power channel reactors that produce electric power and plutonium. This design was identified to be different from the standard reactors that use graphite moderator and water run coolant. The immediate reaction of the emergency crew in Ukraine was to use helicopters to pour concrete (Sarcophagus) and sand on the burning reactor debris. To date, the other thee reactors have been closed down (Nuclear Energy Institute, 2011).
The immediate outcome of the accident was massive release of radioactive components to the environment. 28 workers were killed four months after the incidence with another 19 deign between 1987 and 2004. Still, another 106 workers were treated of acute radiation sickness. After the incidence, about 200,000 workers were involved in the cleanup exercise between 1986 and 1987. It is reported that working who were doping the clean-up job receives doses of radio-active components of between 1 and 100 rem – it should be noted that the average annual dose of radiation for US citizens is set at 0.6 rem (U.S. NRC (a), 2014). Children were reported to have received thyroid doses in areas that received the radio-active contamination after the incidence. Cases of thyroid cancer among children attributable to the accident have been reported in Belarus, Russia, and Ukraine.
Evacuation of people around the Chernobyl over a radius of 30 kilometers was done one month after the incidence. Environmental contamination is probably the most serious long term effects of the accident in Chernobyl. Due to the environmental contamination, sale of milk and vegetables was restricted in the region and also in the world. The surrounding 4200 square kilometer is designated as a no-go zone with 7000 square kilometers being considered as having considerable contamination (ENS News, 2006).
Three- Mile Island Nuclear disaster
The March 28, 1979 nuclear disaster in Three Mile Island in Middletown, Pennsylvania is the worst nuclear incidence in America. The accident that was a partial meltdown of the nuclear reactor was occasioned by failure of the water-coolant pumps of the second reactor that resulted on overheating. The failure of monitoring equipment that control and indicate the levels of control aspects are believed to have failed (US NRC (b), 2014). Although the core material in the reactor melted down, there was no release of radioactive because the containment remained intact. The incidence did not have any fatalities. The immediate reaction of EPA was to place experts to monitor radiation in the environment surrounding the power plant.
Within a short time after the incidence, the meltdown had been adequately controlled. Amid uncertainties in the possibility of released radioactive radiations, the Governor of Pennsylvania ordered immediate evacuation of people who were considered to be at high vulnerability over a radius of five miles around the power plant. In general the incidence was caused by deficiencies in the design of the reactor, personal errors and equipment failure. The immediate changes that were carried out after the incidence included upgrade of the design of the plant and equipment’s to adequately measure and control operations according to specifications. Other measures included enhancement of emergency preparedness and constant and regular monitoring of the plant performance (United States Environmental Protection Agency, 2012). To date the second reactor remains permanently closed where all the fuel has been removed and coolant water drained.
Fukushima Daiichi Nuclear Disaster
The incidence happened in March 11, 2011 following a major earthquake. According to the World Nuclear Association (2014), the 15 metre Tsunami, destroyed the power supply and the cooling system of Fukushima’s three nuclear reactors. Following the incidence, the three cores of the reactors melted down within a period of three days. Unlike the Chernobyl accident in Ukraine and the Three Mile Island incidence in U.S that were largely occasioned by personal errors and design flaws of the reactors, the Fukushima’s accident was as a result of a natural disaster.
The amount of the radioactive elements that were released following the incidence lead to the accident being rated 7 in the INES scale. In total, 940 Pbq of radiation was released following the accident. All the four reactors in the Fukushima power plant were written off after the accident. The situation stabilized after a period of two weeks where the reactors were water-cooled.
There were no immediate fatalities reported after the incidence. Other that cooling of the reactors, the other tasks included measures to prevent release of radioactive material to the environment. Measures to evacuate more than 100,000 residents from areas surrounding the power plant went on. Although the magnitude of the disaster was higher as compared to the Chernobyl and Three Mile Island incidence, the risks to human life and to the environment was considerably low. United Nation researchers indicated, “No discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants," (CBC News, 2014).
Conclusion
Comparing the three nuclear disasters in Chernobyl, Ukraine, Three Mile Island in Middletown, US, and the Fukushima disaster, it will be seen that the Chernobyl accident was the most serious especially in regards to the magnitude of fatalities and environmental impact. While the other two did not involve any deaths, the Chernobyl accident claimed lives of 47 workers and over 4000 children who were diagnosed with thyroid cancer. Still, the level of contamination following the Chernobyl incidence resulted in long-term environmental impacts. In regard to Chernobyl incidence, while the Nuclear Energy Institute (NEI, 2011 ) and the U.S. National Regulatory Commission (NRC, 2014) NRC try establish the actual facts about the occurrence, the ENS news gives the indication that, while the environmental impact of the accidence was measurable, the outcomes of those measurements were subject to differing interpretations from expert. Consequently, contradictory political and economical decisions were made, for instance, the banning of sale and export of milk and vegetables from this region to local and international markets. The ENS News author concludes that, the reported environmental impact of the accident could have been over-exaggerated. Still, the author concludes that while other energy sources like coal mining could be resulting to more deaths as compared to the nuclear accident observed in Chernobyl, the public is not concerned of such incidences. Instead the actual threat of nuclear energy would be far less serious as compared to other energy production processes.
In regard to the Three Mile Island (TMI) Nuclear Disaster, the U.S. Nuclear Regulatory Commission gives the facts about the event. Similarly, the US Environmental Protection Agency (ENA) gives the facts and the responses taken towards the disaster. In general, the two government bodies faulted human errors, equipment failure and design deficiency as the main causes of the TMI accident. In regard to the Fukushima Daiichi accident, World Nuclear Association (2013) gives the indication of limited environmental effects as a result of the accident. The association commends the measures taken in prevention of environmental contamination, for instance, through water treatment and evacuation of the residents around the power plant.
References
ENS News (2006). Chernobyl, the accident scenario and its global impact. ENS News. Issue No.12 2006. Retrieved May 19, 2014 from http://www.euronuclear.org/e-news/e-news-12/presidents-contribution.htm
Nuclear Energy Institute (2011). Chernobyl Accident and its consequences. NEC. Retrieved May 19, 2014 from http://www.nei.org/Master-Document-Folder/Backgrounders/Fact-Sheets/Chernobyl-Accident-and-Its-Consequences
U.S. Nuclear regulatory commission (NRC) (a) (2014). Backgrounder on Chernobyl Nuclear Power Plant Accident. US NRC. Retrieved May 19, 2014 from http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html
U.S. Nuclear Regulatory Commission (NRC) (a) (2014). Backgrounder on the Three Mile Island Accident./ US NRC. Retrieved May 19, 2014 from http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html
Unites States Environmental Protection Agenct (EPA) (2012). Nuclear Incidents: Three Mile Island Nuclear Plant. EPA. Retrieved May 19, 2014 from http://www.epa.gov/radiation/rert/tmi.html
World Nuclear Association, (2014). Fukushima Accident. World Nuclear Association. Retrieved May 19, 2014 from http://www.world-nuclear.org/info/safety-and-security/safety-of-plants/fukushima-accident/
