The Chernobyl disaster was a nuclear disaster which occurred on April 26, 1986 at the Chernobyl nuclear power plant in Pripyat, Ukraine. At that time, Ukraine was part of the Soviet Union. The station was situated just 110 km North of Kyiv.
This event was one of the worst accidents in the history of nuclear power. It was rated level 7, the most severe level, on the International Nuclear Event Scale. The only other accident with a level 7 rating is Fukushima. Because the RBMK reactors used at the plant had no containment building to keep the radiation in, radioactive fallout drifted over parts of the western Soviet Union, Eastern Europe, Scandinavia, the UK, and the eastern United States. Large areas of Ukraine, Belarus, and Russia were badly contaminated. About 60% of the radioactive fallout landed in Belarus. About 360,000 people needed to be moved to other places, where they could live after the accident. In addition, many people suffered from acute radiation poisoning and long term illnesses such as thyroid cancer.
On the day of the accident, there was a planned power reduction. By the beginning of the day shift, the power level had reached 50%. Following this, randomly, one of the regional power stations went offline. It was then requested that the further power reduction would be postponed. Despite this request, the reduction and preparations for a test that was to happen continued.
The accident occurred when the fourth reactor suffered a huge power increase. This led to the core of the reactor exploding. The explosion was so powerful that it blew the 1000 ton steel lid off the reactor. Due to this explosion, large amounts of radioactive materials and fuel were released. This caused the neutron moderator, made of graphite, to start to burn. The fire caused more radioactive fallout to be released, which was carried by the smoke of the fire into the environment.
After the accident, Reactor 4 was covered by a "sarcophagus" made from steel and concrete to stop the escape of more radiation from the lost corium as well as radioactive dust. The sarcophagus was covered in 2016 with the New Safe Confinement structure.
The accident raised concerns about the safety of the Soviet nuclear power industry. The Soviet Union slowed the process of making its nuclear industry bigger for some time. The Soviet government also had to become less secretive as a result of the accident. Since 1991, Russia, Ukraine and Belarus have become separate countries. Those countries have continued to pay the high costs for decontamination (removing the radiation) and health care because of the accident. Exposure to radiation leads to a higher risk of getting cancer.
It is difficult to accurately tally the number of deaths caused by the events at Chernobyl. A 2005 IAEA report tells of 56 direct deaths; of those, 47 were accident workers and 9 were children who died of thyroid cancer. The report thinks that up to 4,000 people may die from long term diseases related to the accident. However, other estimates range from 4,000 to 27,000 by the Union of Concerned Scientists or Greenpeace who estimate that between 93,000 - 200,000 people died as a result of the disaster.
The other three reactors at Chernobyl continued to operate after the disaster because there were not enough other power plants in Ukraine to meet energy demands. Reactor 2 was decommissioned (permanently turned off and stopped being used) in 1991 after a fire in its turbine hall. Reactor 1 was decommissioned in 1996, and reactor 3 was decommissioned in 2000. In 2018, a 3800 panel, 1 megawatt solar plant was opened next to the former nuclear plant.
Prypiat
Pripyat (Ukrainian: При́п'ять, "Pryp”iat’") is an abandoned city in northern Ukraine. It lies in Kiev Oblast, near the border with Belarus. It was home to Chernobyl nuclear power plant workers. The city was abandoned in 1986 after the Chernobyl accident, the worst nuclear reactor accident in history. Before being abandoned, about 48,000 people lived in the city. The city was founded in the 1970s, when the nuclear power plant opened.
The site today is practically a museum showing the late Soviet era. With entirely abandoned buildings, including abandoned apartment buildings (four of which were yet to be used), swimming pools and hospitals, everything inside remains, from records to papers to children's toys and clothing. Pripyat and the surrounding area will not be safe for people to live there for several centuries. Scientists think that the most dangerous radioactive elements will take up to nine hundred years to decay sufficiently to render the area safe.
The city is entirely accessible and is relatively safe on the road, although it is unsafe to go around the city without a radiation dosimeter that measures exposure. The doors of all the buildings are open to reduce the risk to visitors, although many have accumulated too much radioactive material to be safe to visit.
Thyroid cancer
Thyroid cancer is cancer in the thyroid gland.
There are four types of thyroid cancer:
Thyroid cancer can be diagnosed in a few different ways:
"Basic Tests:"
"Special Tests:"
Containment building
Containment building is a building with a nuclear reactor in it. It is built around the reactor to keep the radiation from getting out, if something happens to the reactor. The containment building is the last barrier to the radiation getting into the environment. Containment systems for nuclear power reactors are distinguished by size, shape, materials used, and suppression systems. The kind of containment used is determined by the type of reactor, generation of the reactor, and the specific plant needs.
The Chernobyl accident was very bad partly because the Soviet RBMK reactors used at the Chernobyl power plant had no containment buildings. The explosion, however, was so powerful that it is unlikely a containment building would have completely prevented the release of radiation.
The diagram shows the order of defense layers for a nuclear reactor. The first layer of defense is the inert, ceramic quality of the uranium oxide itself. The second layer is the air tight zirconium alloy of the fuel rod. The third layer is the reactor pressure vessel made of steel more than a dozen centimeters thick. The fourth layer is the pressure resistant, air tight "containment building". The fifth layer is the exclusion zone around the reactor.
Chernobyl
Chernobyl or Chornobyl () is a city in northern Ukraine, near the border with Belarus.
It was a major communications node and important center of trade and commerce, especially in the 19th century. The city is 14.5 kilometers (9 miles) south by south-east of the Chornobyl nuclear power plant, which became known for the Chornobyl disaster. The plant exploded on 26 April 1986; clouds of radioactive particles were released, and the severely damaged containment vessel started leaking radioactive matter. More than 100,000 people were evacuated from the city and other affected areas. Despite the fact that radiation is still being emitted from the nuclear disaster site, the 800-year-old city of Chornobyl survives. As of 2004, government workers still police the zone. They try to clean up radioactive material. Hundreds of people — mostly the elderly — have decided to live with the dangers and have returned to their homes in the zone's towns and villages. Their population was highest in 1987, when there were more than 1200 people. In 2003, there were about 300. There are currently 704 people living in Chornobyl, the houses that have people inside have a sign on the outside saying, Owner of this house lives here.
Klaus Wowereit