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International Journals of Advanced Research in Computer and Software Engineering Research Article February ISSN: 2277-128X (Volume-8, Issue-2) a 2018

Case Study: Disaster Yasar Hussain*, Arvind Rehalia, Akash Dhyani Bharati Vdyapeeth, College of Engineering, New Delhi, India Email- [email protected], [email protected], [email protected]

Abstract— the Chernobyl disaster was the world worst nuclear disaster, took place in the Chernobyl power plant due to of reactor at city in . It led to 31 deaths including fire fighters and workers of the power plant on same day andabout 15 indirect deaths up to 2011. Also around 115000 people were evacuated from a 30 km zone around the plant. In this paper author gives a case study on Chernobyl disaster. And also, author finds the reasons and its effect on the human beings after the accident. And also, the confinement process of reactor number 4.

Keywords— Steam Turbine Test, Technical Flaw, Reaction, Overheating, the Confinement

I. INTRODUCTION The Chernobyl disaster occurred on April 26, 1986 at Chernobyl power plant in Ukraine. It was a catastrophic disaster which occurred due to technical flaws. Basically, the accident was the result of failure of steam turbine test. On April 26, 1986 technicians prepared to test the backup cooling system in reactor number 4. But the routine safety went wrong while the test was ongoing condition. In the reactor number 4, uranium fuel is used to produce a high amount of heat that convert into steam which drive huge turbine to generate electricity for all the reactor. Control rods were inserted inside the uranium to control the reaction and it is crucial for cooling water to pump around the core to prevent overheating. But, as the test was started, all of the rods were removed from the uranium fuel. Due to this mistake, technicians lost the control of the flow of coolant, as a result the temperature of the reactor increased drastically and a high amount of heat was produced, that was sufficient to melt the core. At 1:23 am the reactor number 4 of Chernobyl plant was exploded. Around 8 tonnes of radioactive fuel was spread into the atmosphere of the Ukraine. The toxicity of this explosion was equivalent to 400 bomb . After the explosion in 1986, the reactor number 4was covered by the sarcophagus and plant was again started with three remaining reactor which were in running condition. But due to lake of energy resources the Chernobyl nuclear plant was completely shut down later in year 2000.The Chernobyl accident led to a huge impact on the people of the Ukraine. Abnormalities of insects, deformation of eyes and other parts of the body and natural waste were some of the most common effects of the Chernobyl accident.

II. THE CAUSE ( STEAM TURBINE TEST ) A. Before Steam Turbine Test An easy way to comply with the conference paper formatting requirements is to use this document as a template and simply type your text into it. The construction of Chernobyl nuclear plant was done on 15th august 1972 and the commission was held in 1977 with only one reactor. Two other reactors became operational earlier. The reactor number 4 was newest going online in 1983. The preparation was done in 1986 to test the backup cooling system on reactor number 4with the expectations of some improvement in processing rate.

B. Steam Turbine Test The steam turbine test was held on 26th April 1986. In the reactor number, the uranium fuel is used to produce a high amount of heat which converted the water into steam and with the help of that steam the turbine could be rotated and could produce the energy for the reactors. To control the reaction and overheating of the system, some rods were inserted into the uranium fuel.

C. Result of Steam Turbine Test The preparation for steam turbine test was done properly. But the test was gone horribly wrong, almost all the rods were removed from the uranium fuel. As a result, technicians lost the control over the temperature of the system. And finally a huge amount of heat was produced, which result in the explosion of reactor number 4 of Chernobyl power plant in Ukraine. And also a large amount of toxic radioactive fuel was spread out in the atmosphere.

© www.ijarcsse.com, All Rights Reserved Page | 76 Hussain et al., International Journal of Advanced Research in Computer Science and Software Engineering 8(2) ISSN(E): 2277-128X, ISSN(P): 2277-6451, pp. 76-78 III. EFFECT OF EXPLOSION There were various hazardous effects occurs due to the explosion of reactor number 4 at Chernobyl plant. These effects included some earlier effects which include direct effects and also some indirect effects occurred afterwards.

A. Earlier Effects The explosion led to 31 deaths in total, including fire fighters and workers of Chernobyl nuclear plant and also around 115000 people were evacuated due to the of the explosion in a radius of 30 km around the plant and around 15 more indirect deaths by 2011.

B. Lateral Effects There are many other effects has been seen after the accident at Chernobyl Power Plant related to human, insects and nature etc. The most common effects are 1) Radroach (after the explosion the insects around the Chernobyl were found to be abnormal. The abnormalities are such as deformation of legs, eyes or fur). 2) Eyes abnormalities in human being (it includes either the deformation or unnatural growing eyes). 3) Hydrocephalus (it includes the deformation of body parts usually head, face hands and legs). 4) Limb development (it includes the development of limbs in abnormal fashion). 6) Natural waste (after the accident the growing rate of plant around Chernobyl was decreased and also decomposition of old plants started). 7) (it includes negative effect of brain development).

IV. CONFINEMENT METHODS FOR DAMAGED REACTOR After the explosion, there are two steps has been taken by the till date, first was the emergency construction of sarcophagus and another is New Safe Confinement (NSC) or New Shelter.

A. Sarcophagus After the Chernobyl explosion, there were lot of problems raised related to human health and safety. It is estimated that within the shelter there is 200 tons of radioactive , 30 tons of contaminated dust and 16 tons of uranium and were present. To overcome the effect of toxic radioactive fuel, a secure and successful treatment was needed. Thus, a sarcophagus structure was build over the reactor number 4 between May and October in 1986 to halt the release of radiation into the atmosphere. It was an emergency measure of safety purpose. It was made up of giant metal concrete and the durability of that sarcophagus was estimated around 30 year since its construction. But, the structural condition of the sarcophagus was continuously deteriorated. Later repair of this sarcophagus was seemed to be impossible. Thus a decision to replace the sarcophagus was taken.

B. New Safe Confinement In 1992 Ukraine organized a competition to attract the ideas that would make the Chernobyl safe again. Time frame was quite tight since the sarcophagus that had been built around reactor number 4 was designed to last 30 years. In 1993 Novarka was selected for the construction of New Safe Confinement (NSC or new shelter) with tender partners Vinci Construction Grand projects and Bouygues travdux public. Its design includes the confining of damaged reactor as well as the sarcophagus. Its height(92.5meters), length(150meters) and external span(270meters) can easily describe its huge dimensions. It is a containment style of structure to contain the escape of radiation or toxic gases to maximum pressure of 275 to 550KPa and its architecture is Arch shaped steel structure which would take the confinement air tight for 100 years. Also it is the biggest mobile structure in history. It would weighs more than the Eiffel Tower and can house the Statue of Liberty. The total cost in its construction is around €1.6 billion this much amount was the only hindrance occurred in this project. But in 1997 the was established and it received the donation from all over the world and was managed by the European Bank The construction of NSC was started in September 2010 and it was decided that the encloser would be constructed around 300 meters away from the damaged reactor. The arch was assembled in the ground and lifted in phases on the damaged reactor. The Novarka team started clearing and cleaning of erection in earlier 2010. In April 2010 they started excavating to lay the concrete beams that would be used to slide the structure into position over damaged reactor. By Feb 2012 the first segment was rolled off from the production line. The arch was erected in six phases between November 2012 to October 2014.Work on electric and ventilation system began in June 2015 to prevent corrosion in the confinement. The air between the inner and outer wall was dried and subjected to mild pressure. After some other works, on 14th November 2016, the arch was ready to be pushed in its final position. On 29th November, the

© www.ijarcsse.com, All Rights Reserved Page | 77 Hussain et al., International Journal of Advanced Research in Computer Science and Software Engineering 8(2) ISSN(E): 2277-128X, ISSN(P): 2277-6451, pp. 76-78 arch was shifted to the damaged reactor by travelling the distance of around 300 meters. Some of safety works are still in progress qnd the completion of the project will be done by 2018. Now the NSC is officially on its place.

V. CONCLUSION Author has deeply studied the main cause of disaster and also their direct and indirect effects. And finally, he concluded that the main cause of the accident was the technical flaws in the process of Steam Turbine Test and low safety measure taken during the test. And due to emission of radiation from the reactor, there were number of problems occurred related to human being as well as nature and environment. But after the construction of Confinement, The Ukraine is now safe from the effect of those .

ACKNOWLEDGMENT First of all we would like to express my profound honour to Mr. Arvind Rehalia, Associate professor, Department of Instrumentation and Control Engineering, Bharti Vidyapeeth College of Engineering for his continuous support and advise. With the help of his patience and continual encouragement we are able to complete this case study. We would also like to thank our HOD Mrs Arati Kane and all the faculty members of Department of Instrumentation and Control Engineering for their support and cooperation. And finally, I would like to express my deep respect and gratitude to my parents and my family.

REFERENCES [1] Available at: www.world-nuclear.org [2] Available at: www.youtube.com. [3] Available at: www.en.wikipedia.org.

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