On March 9, Ukraine's National Energy Corporation (Ukrenergo) said the Chernobyl nuclear power plant in Ukraine had been completely cut off. Ukraine's State Nuclear Power Generation Company (Energoatom) warned that radioactive material from the Chernobyl nuclear power plant could leak out. So why did the long-deactivated Chernobyl nuclear power plant leak due to power outages?
In 1977, the Soviet-built Chernobyl nuclear power plant began to generate electricity. The plant had four nuclear reactors, which could generate 4,000 MW of electricity, which at the time supplied one-tenth of Ukraine's electricity. At the time, the plant was a source of pride, and its reliability and safety were considered the best.
However, in 1986, a catastrophe struck. During a test, the power of unit 4 of the nuclear power plant suddenly increased sharply, exceeding the theoretical maximum value by 10 times, resulting in a violent explosion of the reactor core, and a powerful shock wave directly broke through the thick concrete on the top.
After the explosion, the nuclear reactor was directly exposed to the outside, and a large amount of radioactive material leaked out. The first firefighters to arrive at the scene did not know the seriousness of the situation, and they were exposed to a large dose of radiation without protection, which caused them to vomit violently and fall to the ground. Under the action of the atmosphere, a large number of radioactive particles also spread far away.
Scientists estimate that the explosion at the Chernobyl nuclear power plant released a dose of radiation equivalent to the total amount of 400 Hiroshima atomic bombs that exploded at the same time. To stop the further spread of radioactive material in the reactor, hundreds of helicopters airdropped up to thousands of tons of sand and boron carbide in front of and behind.
In nuclear fission reactions, neutrons are the key to triggering chain reactions, and they hit the nucleus of an atom, which can produce energy and new neutrons, which in turn trigger the nuclear reaction. Boron carbide can effectively absorb neutrons from nuclear reactors, thereby terminating nuclear reactions without producing new radioactive material.
In order to completely isolate the bombed nuclear reactor from the outside world, a sarcophagus was built on the reactor with a large amount of reinforced concrete, and its roof alone weighed 35 tons. Due to the tight time of the year, the construction of the sarcophagus was not as strong as in the design.
Considering that the sarcophagus had been eroded by nuclear wastewater from the ruins for many years, its structure might not be sustainable for a long time, and in 2010, a new sarcophagus was started. After six years of construction, the new sarcophagus, which cost 1.5 billion euros and weighed 30,000 tons, was completed. People can remotely control the boom inside the new sarcophagus to safely remove the old sarcophagus and nuclear reactor ruins.
In this first mega-nuclear power accident in human history, hundreds of thousands of people participated in the rescue, and people paid a heavy price. Dozens of people died directly from radiation that year, but the number of people who have been affected by radiation for a long time is difficult to count, and the most serious estimate is that 1 million people died in the accident.
In the years after the accident, the Chernobyl nuclear power plant did not stop operating. Due to the lack of electricity in Ukraine, three other units of the nuclear power plant continue to operate. It was not until 2000, after receiving huge compensation from the European Union, that Ukraine completely shut down the Chernobyl nuclear power plant.
The recent emergency at the Chernobyl nuclear power plant has once again attracted the attention of the world. According to the State Nuclear Power Generation Company of Ukraine, there are currently 20,000 spent fuel (used nuclear fuel) components at the Chernobyl nuclear power plant that need to be cooled by a cooling system, which is not possible without electricity.
Although the nuclear power plant has a backup diesel generator, it can only last 48 hours. For now, the power system cannot be restored. This means that after 2 days, the nuclear power plant that loses power will leak radioactive material, which will undoubtedly endanger the more than 2,000 people currently working at the nuclear power plant.
However, the International Atomic Energy Agency (IAEA) said that the power outage would not have a significant impact on the safety of the Chernobyl nuclear power plant. Earlier, the International Atomic Energy Agency said it was concerned about the situation that the Chernobyl nuclear power plant had stopped transmitting monitoring data to the agency.
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