Monday, July 22, 2019

The Fukushima Nuclear Power Plant Accident Essay Example for Free

The Fukushima Nuclear Power Plant Accident Essay Abstract The Fukushima nuclear accident triggered a large-scale nuclear leak, which has had an immeasurable impact on the global ecological environment. This article addresses, in depth, features of the Fukushima Nuclear Power Plant accident: during the incident, the impact of the incident, and aspects of the aftermath. Through an analysis of the Fukushima Nuclear Power Plant accident, certain referential and significant aspects of the nuclear industry are clear. Introduction: In a strong earthquake, which occurred on the afternoon of March 11, 2011, the Fukushima Daiichi Nuclear Power Plant in Japan was severely damaged; this led to a leakage of radioactive substances, causing considerable concern around the world. In recent years the promotion of a low-carbon economy has resulted in nuclear power plants being seen as one of the best producers of low-carbon energy; the accident has raised Governments’ concern. A study of the impact of the Fukushima Daiichi Nuclear Power Plant accident on the surrounding environment, as well as how great significance in promoting the development of a global nuclear future. [1] 1. The Fukushima Nuclear Power Plant: the whole story. The Fukushima Daiichi Nuclear Power Plant used the early BWR (Boiling Water Reactor), the standard was low, and had technical defects; poor security was the cause of the accident. The main reason for the accident was the design of the nuclear power plant which did not take into account the double impact of a powerful earthquake and consequential tsunami. In fact, the earthquake did not completely destroy the nuclear power plant; it was the tsunami that followed that destroyed the emergency diesel generators, and caused the whole plant to lose all its internal and external AC power supply. The Fukushima Daiichi nuclear reactor used water as a coolant and moderator, but the water was boiling in the reactor and changed into steam in the turbine generator. The tsunami led to the loss of the emergency power supply, and the failure of the necessary cooling of the reactor after shutdown. This led to an elevated temperature and a pressure increase; for safety it had to release the steam to release the pressure. The loss of coolant, which it could not efficiently replace, resulted in part or all of the fuel being exposed. BWR steam with radioactive substances were discharged directly through the pressure vessel dry well and then released into the atmosphere. Due to the loss of power, reactor waste heat could not find an appropriate way to escape and the temperature of the core fuel rose causing the shell zirconium to react with steam to produce hydrogen. The hydrogen was released into the plant, and continued to accumulate, finally leading to the explosion in the plant. After the accident, the core melted and was destroyed; this then led to a further expansion of nuclear contamination. [1] 2. The Fukushima Nuclear Effect on Humans Physicist Kirby Kemper, from Florida State University, said that if there was a complete nuclear reactor core melt-down, some of the most radioactive substances, such as uranium and other heavy metals, would drop to the bottom of the pressure vessel, these substance would not be emitted into the atmosphere, and could, by nuclear radiation clean-up personnel, be special process cleaned. However, some of the radioactive chemical substances would be released, fourth grain of sand size particle morphology, these substances include iodine-131, strontium-90, and cesium-137. These are a great threat to the human body, because these radioactive substances can imitate the elements required by the human body’s natural tissue components, such as radioactive iodine-131, and easily enter into the body’s tissues and organs. Radioactive iodine under certain conditions can be rapidly dispersed in the air and water. However, iodine-131‘s half-life is only eight days, which means that in a few months it will completely decay. Radioactive iodine can be dispersed through the air to the human body; it can be deposited on grass which is then eaten by cows. The cows then produce contaminated dairy products and through this transmit it into the human food chain. It may also be deposited on the leaves of vegetables or in seafood and fresh water also for human dietary consumption. [1,2] The half life of strontium-90 is 29.1 years, and due to its chemical properties being similar to calcium, is often found in human bones and teeth. In the Chernobyl nuclear power plant accident, there was a large amount of strontium- 90 released into the air, and deposited in the former Soviet Union, Scandinavia and other regions. Strontium-90 goes into the human body through food and drinking water, much of its intake is often associated with bone disease, bone and soft tissue tumors and leukemia. [2,3,4] The half–life of Cesium-137 is 30 years, another high risk substance which is released from a nuclear reactor core and often in the body through food and water intake, or by entering the body through the respiratory organs. A body, which is exposed to Cesium-137, will have an increased risk of cancer. [2,3,4] 3. The Fukushima Nuclear Power Plant and Ecological Problems The Fukushima nuclear power plant accident caused huge ecological environmental hazards; in general it caused pollution. (1) Air Pollution Air causes the spread of nuclear radiation. However, the concentration of radioactive material released into the atmosphere will gradually be diluted with increased distance. It is not biologically transmitted, it is physically spread. Radioactive nuclear substances are spread through atmospheric circulation and dispersion, with attenuation according to the laws of nature. [5] Following the explosion of Unit 1 of the Fukushima Nuclear Power Plant, at around 11.00am on March 14, there was a second hydrogen explosion; this time it occurred in Unit 3. This was followed, at about 6:00am on the 15th, by an explosion in Unit 2, where the reactor vessel was damaged more seriously in two days than compare to the consequences of the explosion of Unit 1. According to monitoring, under the influence of atmospheric movement, the Fukushima Nuclear Power Plant released radioactive substances on the 15th more than 20 times the normal standard. This indicates that the explosion caused pollution of the atmosphere and affected the ecological environment of neighboring countries; with atmospheric circulation, these radioactive elements were carried outside of Japan. [5,6] (2) Water Pollution The ground water near the Fukushima Daiichi Nuclear Power Plant’s Units 1 and 2 nuclear reactors saw the concentration of radioactive iodine and radioactive cesium surge a number of times, which no doubt contributed to the groundwater pollution. Fukushima Nuclear Power Plant radioactive material continues to flow into the ocean where marine life will be threatened. According to The New York Times, reported that researchers who extracted water samples near the nuclear power plants detected cesium-137 and iodine-131 radioisotope concentration, suggesting that the nuclear leakage accident had caused marine pollution. [7] (3) Soil Pollution Japan’s Kyodo News quoted a Japan Atomic Power Environmental Preparedness Agency expert reporting that in a 600 square km northwest region soil near the Fukushima Nuclear Power Plant, the radioactive cesium activity was 1.48 million per square meter Becquerel, reaching the Chernobyl nuclear power plant explosion mandatory evacuation standards. This is data obtained by the Japanese Government Commission on Nuclear Energy Research. At the nuclear power plant in the northwest region most severely affected after the Fukushima Unit 1 nuclear power plant accident, the Japanese government evacuated about 80,000 people from the vicinity. Earlier, the Japanese Prime Minister, Naoto Kan, said that the date the people will be able to return their homes will not be earlier than the beginning of the next year. [8,9] (4) Food Chain Contamination University of Florida chemical oceanographer and environmental radioactivity expert, Bill Burnett, said that although iodine’s half-life is only eight days in the short term, there is no doubt that the radiation will be a threat and have an impact on the survival of marine life. But the greater potential impact of the Fukushima Nuclear Power Plant leakage is from that of cesium, because the decay time of cesium up to 30 years. If marine animals’ intake irradiated plants and small prey, then the marine food chain will be contaminated. Particularly noteworthy, is the fact that algae and other plants quickly absorb iodine. Previous studies have shown that toxic metal and radiation interactions suppress the immune system of vertebrates, causing them to be more susceptible to disease. Consequently, the extent of potential damage to the environment and human health is great. [10] In addition, nuclear power plants and other power plants discharge waste heat. The laws of thermodynamics indicate that the conversion efficiency of thermal energy cannot be 100%. Whether the use coal or solar system, the result will be the same. Modern coal or oil power plant efficiency is up to 40%, the efficiency of nuclear power plants is currently only 33%. Coal power stations release 15% of waste heat through the chimney, and 45% of the water heat from the cooling water discharge. However, 67% of nuclear power plant waste heat is from the cooling water discharged into rivers or sea water. The rising water temperatures caused by this has a significant impact on aquatic life. If the water temperature is too high, it will cause the death of fish, and accelerate the growth of algae, causing the water to lack oxygen. [10] 4. Conclusion Nuclear power is a clean energy source, under normal operation the power plant emissions of radioactive radiation is not large, in fact the radioactive substances emitted by coal-fired power stations is said to be much higher than nuclear power stations. Ultimately, there is no energy that can be said to be absolutely safe and clean. In accepting an energy choice, it is necessary, firstly, to rationally face security risks. Secondly, reactor technology and security is under a process of development. The problems faced by nuclear power plants, through the Fukushima incident, are a very important reference point for nuclear power to improve its security program. For example, nuclear power plants should not be placed in an earthquake zone, particularly not on a fracture layer. The Fukushima Daiichi Nuclear Power Plant design, while taking the impact of earthquakes into account, ignored the impact of a consequential tsunami. The nuclear power plant disaster illustrates the need to take multiple natural disasters into account. Furthermore, nuclear power plant design needs to attach importance to the development of emergency plans rationality and feasibility in the event of an accident. With a belief in continuing scientific and technological progress, the security of nuclear power plants of the future should continue to improve. [11,12] References [1] Fukushima: What happened – and what needs to be done. BBC. 10 April 2011. Retrieved 22 April 2011. [2]Takenaka, Kiyoshi (12 March 2011). Japans TEPCO preparing to release radiation from second reactor. Reuters. Retrieved 12 March 2011. [3]Radiation levels spike at Japanese nuclear plant. CNN. 15 March 2011. Retrieved 15 March 2011 [4]Frank N. von Hippel (September/October 2011 vol. 67 no. 5). The radiological and psychological consequences of the Fukushima Daiichi accident. Bulletin of the Atomic Scientists. pp. 27–36. [5]Hydrogen explosions Fukushima nuclear plant: what happened? Unit 1 nuclear power plant Fukushima Pressure. TEPCO. Retrieved 8 April 2011. [6]3 nuclear reactors melted down after quake, Japan confirms. CNN. 7 June 2011. Retrieved 13 July 2011. [7]Radioactive water from Japan nuclear plant leaks in sea. BBC News. 2 April 2011. Retrieved 7 April 2011. [8]Timeline: Japan power plant crisis. BBC News. 13 March 2011. Retrieved 15 March 2011. [9]Japans unfolding disaster bigger than Chernobyl'. New Zealand Herald. 2 April 2011. [10] â€Å"Fukushima. Radioactive Cesium Contmination of Japan’s Food Chain.† 3 August, 2012. [11]Fukushima faced 14-metre tsunami. World Nuclear News. 23 March 2011. Retrieved 24 March 2011. [12]Justin McCurry. Japan raises nuclear alert level to seven. The Guardian. 12 April 2011

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.