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The Chernobyl disaster happened on April 25 and 26, 1986, at the Chernobyl nuclear power station in the Soviet Union. It is one of the worst disasters in the history of nuclear power generation.

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Table of Contents

When did the Chernobyl disaster occur?

What happened in the Chernobyl disaster?

How many people died as a result of the Chernobyl disaster?

How big was the exclusion zone created after the Chernobyl disaster?

What effects did the Chernobyl disaster have?

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Chernobyl disaster, accident in 1986 at the Chernobyl nuclear power station in the Soviet Union, the worst disaster in the history of nuclear power generation. The Chernobyl power station was situated at the settlement of Pryp'yat, 10 miles (16 km) northwest of the city of Chernobyl (Ukrainian: Chornobyl) and 65 miles (104 km) north of Kyiv, Ukraine. The station consisted of four reactors, each capable of producing 1,000 megawatts of electric power; it had come online in 1977-83.

The explosion at Unit 4 and initial containment efforts

The disaster occurred on April 25-26, 1986, when technicians at reactor Unit 4 attempted a poorly designed experiment. Workers shut down the reactor's power-regulating system and its emergency safety systems, and they withdrew most of the control rods from its core while allowing the reactor to continue running at 7 percent power. These mistakes were compounded by others, and at 1:23 am on April 26 the chain reaction in the core went out of control. Several explosions triggered a large fireball and blew off the heavy steel and concrete lid of the reactor. This and the ensuing fire in the graphite reactor core released large amounts of radioactive material into the atmosphere, where it was carried great distances by air currents. A partial meltdown of the core also occurred.

Disasters of Historic Proportion

On April 27 the 30,000 inhabitants of Pryp'yat began to be evacuated. A cover-up was attempted, but on April 28 Swedish monitoring stations reported abnormally high levels of wind-transported radioactivity and pressed for an explanation. The Soviet government admitted there had been an accident at Chernobyl, thus setting off an international outcry over the dangers posed by the radioactive emissions. By May 4 both the heat and the radioactivity leaking from the reactor core were being contained, albeit at great risk to workers. Radioactive debris was buried at some 800 temporary sites, and later in the year the highly radioactive reactor core was enclosed in a concrete-and-steel sarcophagus (which was later deemed structurally unsound).

Deaths, radioactivity, and the creation of the Chernobyl Exclusion Zone

Some sources state that two people were killed in the initial explosions, whereas others report that the figure was closer to 50. Dozens more people contracted serious radiation sickness; some of them later died. Between 50 and 185 million curies of radionuclides (radioactive forms of chemical elements) escaped into the atmosphere-several times more radioactivity than that created by the atomic bombs dropped on Hiroshima and Nagasaki, Japan. This radioactivity was spread by the wind over Belarus, Russia, and Ukraine and soon reached as far west as France and Italy. Millions of acres of forest and farmland were contaminated, and, although many thousands of people were evacuated, hundreds of thousands more remained in contaminated areas. In addition, in subsequent years many livestock were born deformed, and among humans several thousand radiation-induced illnesses and cancer deaths were expected in the long term. The Chernobyl disaster sparked criticism of unsafe procedures and design flaws in Soviet reactors, and it heightened resistance to the building of more such plants. Chernobyl Unit 2 was shut down after a 1991 fire, and Unit 1 remained on-line until 1996. Chernobyl Unit 3 continued to operate until 2000, when the nuclear power station was officially decommissioned.

Following the disaster, the Soviet Union created a circle-shaped exclusion zone with a radius of about 18.6 miles (30 km) centred on the nuclear power plant. The exclusion zone covered an area of about 1,017 square miles (2,634 square km) around the plant. However, it was later expanded to 1,600 square miles (4,143 square km) to include heavily radiated areas outside the initial zone. Although no people actually live in the exclusion zone, scientists, scavengers, and others may file for permits that allow them to enter for limited amounts of time. With the dissolution of the Soviet Union in 1991, control of the site passed to Ukraine. In 2011 the Ukrainian government opened parts of the exclusion zone to organized tour groups, and Chernobyl and the abandoned city of Pryp'yat became popular destinations for so-called "dark tourists." During the Russian invasion of Ukraine in 2022, Russian forces attacking from Belarus captured Chernobyl after a brief but pitched battle. Combat at the site of the world's worst nuclear disaster led to concerns about damage to the containment structure and the possibility of widespread radioactive contamination.

The Editors of Encyclopaedia Britannica Michael Ray.

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Chernobyl disaster | Causes, Effects, Deaths, Videos, Location, & Facts

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Chernobyl disaster, accident at the Chernobyl nuclear power station in the Soviet Union in 1986, the worst disaster in nuclear power generation history. Between 2 and 50 people were killed in the initial explosions, and dozens more contracted serious radiation sickness, some of whom later died.

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The Chernobyl disaster occurred when technicians at nuclear reactor, They attempted a poorly designed experiment. They shut down the reactor’s power system and its emergency safety systems, and they removed control rods from its core while allowing the reactor to run at 7 percent power. These mistakes led to an uncontrolled chain reaction that started to have several massive explosions in it.

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What are three isotopes were released in atmosphere and contaminated several parts of the Europe?

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What are three isotopes were released in atmosphere and contaminated several parts of the Europe?

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The three isotopes were Iodine-131, Strontium-90 and Caesium-137 that released in atmosphere and contaminated several parts of the Europe.

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Iodine-131 collects in the thyroid gland which people exposed to it in chernobyl disaster, it increased the risk of thyroid disease(thyroid cancer.) Thyroid cancer is common that the energy from ionizing radiation breaks the chemical bonds in DNA, resulting in a number of different types of damage. Which resulted that many children and adults died, due to the dangerous Iodine-131 that leads to have a thyroid cancer.

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Once it goes into the body, Strontium-90 is like a calcium and it incorporated into bones and teeth, where it can cause cancers of the bone, bone marrow, and soft tissues around the bone.

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How the region was affected by radioactive contamination in chernobyl?

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How the region was affected by radioactive contamination in chernobyl?

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After the accident, radioactive materials were deposited mostly on open surfaces such as lawns, parks, roads, and building roofs, for instance by contaminated rain.  For example, radioactive deposits were larger in areas where it was raining when the contaminated air masses passed. Also, because radioactive strontium particles are heavier than many other radioactive particles, they were deposited within 100 km of the destroyed reactor.

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Caesium-137 can cause burns, acute radiation sickness, and even death like in chernobyl disaster. It increases the risk for cancer because of exposure is at high energy of gamma radiation.