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| Inside story of Fukushima nuclear mishappening | | | Dr.Rajkumar Singh | 1/24/2020 9:50:54 PM |
| In the history of nuclear plant accidents, an unparallel incident took place at 3.41 pm on 11th March 2011 in the Fukushima Daiichi nuclear power plant of Japan. In this mishappening there were extraordinary natural forces in action and no one imagined that the unlikely combination of natural and man-made disasters would occur together-a massive earthquake, a towering tsunami and the failure of the so-called fool-proof safety and containment strategies. Without power, water could not be pumped into the reactors to cool them and soon they began to overheat and over pressurise. Twenty- four hours later, an explosion caused by a build up of hydrogen at reactor one ripped off the walls and roof. It was estimated after the incident that Fukushima released about a tenth of the radiation expelled into the atmosphere at Chernobyl. Before the disaster Japan was the world's third biggest user of nuclear power and had been planning to increase nuclear's share of the mixed to 50 per cent by 2030.
Internal making of reactors
In fact, in this type of reactors water is used to cool the reactor core and produce steam to turn the turbines that make electricity. The water contains two of the least dangerous radioactive materials - radioactive nitrogen and tritium. Normal plant operations produce both of them in the cooling water and they are even released routinely in small amounts into the environment, usually through tall chimneys. Nitrogen is the most common gas in the earth's atmosphere, and at a nuclear plant the main radioactive form is known as nitrogen-16. It is made when speeding neutrons from the reactor's core hit oxygen in the surrounding cooling water. This radioactive form of nitrogen does not occur in nature. The danger of nitrogen-16 is an issue only for plant workers and operators because its half- life is only seven seconds. A half life is the time it takes half the atoms of a radioactive substance to disintegrate. The other form of radioactive materials often in the cooling water of a nuclear reactor is tritium. It is a naturally occurring radioactive form of hydrogen, sometimes known as heavy hydrogen. It is found in a trace amount in ground water throughout the world. Tritium emits a weak form of radiation that does not travel very far in the air and cannot penetrate the skin. After Fukushima, the big worries were on the reported release of radioactive material - radioactive iodine and cesium, iodine-131 and potassium iodine. The central problem in assessing the degree of danger is that the amounts of various radioactive releases into the environment are now unknown, but the properties of the materials and their typical interaction with the human body give some indication of the threat.
Immediate effects on Japan
On the whole, Fukushima forces us to question our beliefs about nuclear energy. While nuclear power is born out of science, the nuclear it is subject to a variety of scientific, political, economic, military, nationalist and social factors. The crisis at Fukushima forced Japan into a fundamental rethink of its policy on nuclear power. As part of the policy in post-accident phase, dozens of nuclear reactors not directly affected by the tsunami have gone offline to undergo regular maintenance and safety checks and utilities have turned to coal, oil and gas-fired power plants to keep industry and households supplied with electricity imports. In line none of Japans idle reactors will be permitted to go back online until they pass stringent "stress tests" simulations designed to test their ability. Japan was briefly without nuclear power after Fukushima accident as all 50 working reactors were closed for safety checks It was only in June 2012 Yoshihiko Noda, the Prime Minister of Japan, approved the restart of two reactors in Western Japan amid fears that the country would experience power cuts during the summer. It also prepared the country for a historic policy shift on nuclear power industry and households supplied with electricity imports. In line none of Japans idle reactors will be permitted to go back online until they pass stringent "stress tests" simulations designed to test their ability to withstand catastrophic events. Japan was briefly without nuclear power after Fukushima accident as all 50 working reactors were closed for safety checks It was only in June 2012 Yoshihiko Noda, the Prime Minister of Japan, approved the restart of two reactors in Western Japan amid fears that the country would experience power cuts during the summer. It also prepared the country for a historic policy shift on nuclear power.
Further plans of Tokyo
Based on facing the reality of the grave accident and by learning lessons from the incident, the government has decided to review the national energy strategy. On March 11, 2011, it has go ne down in history as a dark day for Japan, the government's September 14, 2012 decision to end its reliance on nuclear power. By 2040 to closing down all 50 reactors will forever be remembered as a defining moment. A policy document, released by the Japanese government on 14th September 2012 read. One of the key pillars of the new strategy is to achieve a society that does not depend on nuclear energy as soon as possible. The plan calls for renewable energy to comprise 30 per cent of Japan's future energy mix-an eightfold rise from 2010 levels and the development of sustainable ways to use fossil fuel. This is a strategy to create a new future Japan should aim to reduce greenhouse gas emissions by about 20 per cent from 1990 levels and to reduce energy consumption through greater efficiency by about 10 per cent from 2010 levels. In addition, the Fukushima mishap has had its reverberations in several other countries including France, Germany, India, China, Italy, Israel and Indonesia. By 2025, France will cut its reliance on nuclear energy by 25 per cent from the current level of 75 per cent by shutting down 24 reactors. After Fukushima, Germany, by 2020, intends to derive 35 per cent of its energy needs from renewable source. India and China, who are both pushing ahead with their own nuclear plans, have also taken pause to look at their safety aspect. Although limited but there have also been negative reactions in Italy, Israel and Indonesia. Some countries who were thinking about nuclear power have now restrained. Now perhaps, the focus will be on developing technologies for generating alternative sources of energy. |
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