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The Chernobyl disaster Prepared :student 33 group Natural Sciences and Geography department Podgorodetska Olga
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source or nonpoint source pollution.
Adverse air quality can kill many organisms including humans. Ozone pollution can cause respiratory disease, cardiovascular disease, throat inflammation, chest pain, and congestion. Water pollution causes approximately 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries.
The major forms of pollution are listed below along with the particular contaminant relevant to each of them: Air pollution Light pollution Noise pollution Water pollution
Air pollution:- the release of chemicals and particulates into the atmosphere. Common gaseous pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometre size PM10 to PM2.5.
Chernobyl Disaster: The Worst Nuclear Air Disaster in History 100 times more radioactivity than Hiroshima
The Chernobyl Nuclear Power Plant Located 11 miles north of the city of Chernobyl Plant consisted of 4 reactors Produced 10% of Ukraine’s electricity Construction began in the 1970’s Reactor #4 was completed in 1983 At the time of the accident, reactors #5 and #6 were in progress
Background Type: Reaktor Bolshoy Moshehnosty Kipyashiy (RBMK) RBMK, a Russian acronym translated roughly means “reactor (of) high power (of the) channel (type)” reactor cooled by water and moderated by graphite
Reactor Plant Scenario As the reaction occurs, the uranium fuel becomes hot The water pumped through the core in pressure tubes removes the heat from the fuel The water is then boiled into steam The steam turns the turbines The water is then cooled Then the process repeats
What happened? Saturday, April 26, 1986: -Reactor #4 was undergoing a test to test the backup power supply in case of a power loss. -The power fell too low, allowing the concentration of xenon-135 to rise. -The workers continued the test, and in order to control the rising levels of xenon-135, the control rods were pulled out.
Reasons for the accident Workers lack of knowledge of reactor physics and engineering, as well as lack of experience and training Delay The night shift was not prepared to carry out the experiment But it was still carried out The operators seem to have been unaware of the xenon poisoning Insufficient communication between the safety officers and the operators in charge of the experiment Disabled all safety systems Poor quality (typical Soviet craftsmanship) Rushed design A lot of corners cut to meet deadline Bonus for meeting deadline
The Reactor After the Explosion After the explosion, most of the plant is still standing. Some might think from this picture that the disaster wasn’t all that bad, but what makes the Chernobyl disaster the worst in history is the sheer volume of radioactive materials that where spewed across the European continent.
Summary of Facts April 26, 1986: Chernobyl nuclear power plant Operator errors cause a reactor explosion Explosion releases 190 tons of radioactive gasses into the atmosphere Fire starts that lasts 10 days People: 7 million lived in contaminated areas; 3 million were children Wind: Carries radiation far distances
Chernobyl Catastrophe Victims comprise four main groups Group 1: persons involved in the clean-up operations at the Chernobyl Nuclear Plant (liquidators). Group 2: Persons evacuated from the exclusion zone in 1986 (evacuees). Group 3: Persons resident in the territories monitored (relocation zone) or resident there immediately after the accident (residents) Group 4: Children born to parents in Groups 1-3 (offspring).
Immediate Impact 231 people were hospitalized immediately due to acute radiation sickness. 31 of them eventually died. Most of these people were workers in the plant or local firefighters.
The Clean Up “Liquidators” These were firemen who helped put out the fires and helped clean up the radiation Most did not realize the dangers of radiation. Many later died from radiation, because they didn’t wear protection. An estimated 8,000-20,000 to date have died (20% from suicide) Robots United States supplied Specifically designed to enter reactor core and help build the sarcophagus
Clean Up Approximately 300,000 to 600,000 liquidators were involved in the cleanup of the 30 km evacuation zone around the plant in the years following the meltdown.
Evacuation Following the accident hundreds of thousands of people had to be evacuated and between 1990 and 1995 an additional 210,000 people were resettled. People evacuated: -May 2-3 (1 week later) 10 km area (45,000 people) -May 4 30 km area (116,000 people) -50,000 people from Pripyat, Ukraine were evacuated 2 days after the accident.
Long term Impact International spread of radioactivity detected over all of Europe except for the Iberian Peninsula The nuclear meltdown provoked a radioactive cloud which floated over Russia, Belarus, Ukraine and Moldova, but also the European part of the Republic of Macedonia, Croatia, Turkey, Bulgaria, Greece, Romania, Lithuania, Latvia, Finland, Denmark, Norway, Sweden, Austria, Hungary, the Czech Republic and the Slovak Republic, Slovenia, Poland, Switzerland, Germany, Italy, Ireland, France and the United Kingdom (UK).
Long term Impact (cont) Radioactive release Highly radioactive compounds that accumulate in the food chain, such as some isotopes of iodine and strontium are particularly dangerous. All of the noble gases, including krypton and xenon, contained within the reactor were released immediately into the atmosphere by the first steam explosion. About 55% of the radioactive iodine in the reactor was released, as a mixture of vapor, solid particles and as organic iodine compounds. Plutonium’s half life is 24,400 years
Long term Impact (cont) Fauna and vegetation pine forest in the 10km2 surrounding of the reactor turned ginger brown and died, earning the name of the "Red Forest“ Some animals in the worst-hit areas also died or stopped reproducing.
Long term Impact (cont) Health effects Mental health and psychological effects High levels of stress, anxiety and medically unexplained physical symptoms continue to be reported among those affected by the accident. Reproductive and hereditary effects and children's health Birth defects, infertility
Economic cost (cont) Coping with the impact of the disaster has placed a huge burden on national budgets. In Ukraine, 5–7 % of government spending each year is still devoted to Chernobyl-related benefits and programmes. In Belarus, government spending on Chernobyl amounted to 22.3% of the national budget in 1991, declining gradually to 6.1% in 2002. Total spending by Belarus on Chernobyl between 1991 and 2003 was more than USD 13 billion.
What has been done to reduce exposure in contaminated areas? The Soviet and Commonwealth of Independent States (CIS) authorities introduced a wide range of short and long term environmental countermeasures to mitigate the accidents negative consequences: Decontamination of settlements in contaminated regions Exclusion of contaminated pasture grasses from animal diets and rejection of milk based on radiation monitoring data. Feeding animals with “clean” fodder Application of Cs-binders, such as Prussian blue, to prevent contamination of milk and meat