Question

case study of nuclear disaster

Answer 1

This assignment purpose is to do analysis case studies and the Fukushima nuclear disaster. The purpose of this work is for students to use the appropriate method to verify each problem. To study a range of industries (EAT221), there are several levels of courses. In order to complete this news report, the instructor provides the learning needs of students. It also describes how to improve the Tokyo electric power company management of nuclear power plants, manufacturing and safety. Students study was to create recommendations on the basis of this report the nuclear disaster. This case study is one way to measure the impact or accidents related to the theme of the students in the classroom effectively. In addition, we recommend that the case study, students will analyze the problem in an appropriate way.

Introduction

Fukushima Nuclear Power Plant also known as Fukushima Dai-ichi is located on a 3.5-square-kilometre (860-acre) between the towns of Futaba and Okuma of Fukushima Prefecture, Japan. The plant consists of six boiling water reactors (BWR). These light water reactors drove electrical generators with a combined power of 4.7 GW, making Fukushima Daiichi one of the 15 largest nuclear power stations in the world. First nuclear power plant was designed, built, and was run in conjunction with General Electric, Boise, and Tokyo Electric Power Company (TEPCO).

March 11, 2011, the 9.0 earthquake and followed by a not expected tsunami to hit at the power plant factory in Japan cause a major damage to the plant. It trigger the evacuation zone of 30 km around the plant which would lead to nuclear radiation leak. The earthquake and tsunami has disabled the cooling system of the nuclear reactor. As of April 2012, Units 1-4 are no longer in operation. In Unit 1 to shut down on April 20, unit 2-4, closed on April 19, 2012 while was the last of these four units. It was the most powerful disaster that have been hit the country so far. It has resulted in a massive tsunami that destroyed many towns and villages, nearly have led to 20 000 people death.

3. Man-Made Disaster

From the natural disaster, 9.0 earthquake followed by a tsunami it was truly unfortunately become a man-made disaster when the nuclear reactor melt-function cause many death in the country. The power plant shouldn't have shut down automatically when the earthquake happen because when the plant was build it already have been consider to avoid this accident happen when the natural disaster happen.

Answer 2

Case Study: Chernobyl                      The Chernobyl disaster was a nuclear accident that occurred at the Chernobyl Nuclear Power Plant in on April 26, 1986. It is considered the worst nuclear power plant disaster in history. A nuclear meltdown in one of the reactors caused a fire that sent a plume of radioactive fallout that eventually spread all over Europe.IntroductionOn April 26, 1986, a test was scheduled at the Chernobyl Nuclear Power Plant to test a method of keeping the reactors properly cooled in the event of a power grid failure. If the test had gone as planned, the risk to the plant was very small. When things did go wrong, though, the potential for disaster was miscalculated and the test was continued even as serious problems arose. Meltdown occurred at 1:23 AM, starting a fire that dispersed large quantities of radioactive materials into the atmosphere. The amount of radioactive material released was 400 times more than the amount the atomic bombing of Hiroshima released. The fallout would be detected in almost all parts of Europe.Before the accidentNuclear reactors require active cooling in order to remove the heat generated by radioactive decay. Even when not generating power, reactors still generate some heat, which must be removed in order to prevent damage to the reactor core. Cooling is usually accomplished through fluid flow, water in Chernobyl's case.The problem at the Chernobyl plant was that following an emergency shutdown of all power, diesel generators were needed to run the cooling pumps. These generators took about a minute to attain full speed, which was deemed an unacceptably long time for the reactor to be without cooling. It was suggested that the rotational momentum of the winding down steam turbine be used to power the pumps in the time between shutdown and the generators being ready. A test was devised to test this method in 1982, but the turbine did not prove to be successful in providing the required voltage as it spooled down. Two more tests would be conducted in the following years, but would also be unsuccessful. The fourth test was scheduled to be run on April 25, 1986.The experiment was devised in such a way that if it had gone as planned, the disruption and danger to the plant would be very minimal. First, the reactors would be brought down to low power, between 700 and 800 megawatts. Then the steam turbine would be run up to full speed and then turned off. The power generated by the winding down generators would then be measured to determine if it was sufficient to power the cooling pumps in the time before the diesel generators got up to full speed.By 1986, the plant had been running for two years without the implementation of a method to keep the cooling pumps running continuously following an emergency shutdown. This was an important safety measure that the plant was lacking, which presumably gave the plant managers a considerable amount of urgency in completing another test.The experimentPreparing for the experimentThe experiment was scheduled to run during the day shift of 1985, while the night shift would only have to maintain cooling of the radioactive decay in the shut-down plant. However, another power generator nearby unexpectedly shut down, necessitating the need for the Chernobyl plant to delay the test and continue producing power. The experiment would be resumed at 11:04 PM, by which time the day shift had departed and the evening shift was about to leave. This meant that the experiment would be conducted in the middle of two shifts, leaving very little time for the night shift employees to be briefed about the experiment and told what to do.The power reduction of reactor 4 to 700 MW was accomplished at 00:05 AM on the 26th of April. However, the natural production of a neutrino absorber, Xenon-135, led to a further decrease in power. When the power dropped to about 500 MW, the night shift operator committed an error and inserted the reactor control rods too far. This caused the reactor to go into a near-shutdown state, dropping power output to around 30 MW.