International Agency of Nuclear Energy has identified seven-point scale to assess the accidents at nuclear plants. So far, seven points was assessed only the Chernobyl accident. In 25 years, the same estimate obtained and the accident in Fukushima. What else is different about these and similar accidents?
Both tragic accident separated almost exactly 25 years. The reactor at Chernobyl exploded April 26, 1986, earthquake and tsunami came in Fukushima March 11, 2011.
The Chernobyl station is located on the Pripyat River for 130 km from Kiev and a few kilometers from the border with Belarus. The town of Chernobyl, which gave the name of the station lies within 18 km to the south.
Fukushima station is located on the oceanfront in the city of Fukushima Prefecture Akuma is 200 km from the Japanese capital Tokyo, and as much as from Chernobyl, Belarus Gomel.
Type of reactor
In Chernobyl reactor worked the Soviet RBMK (Russian abbreviation of "high-power channel reactor"), or channel vodagrafitny reactor. Retarders nevtronav here is graphite and coolant — water. In all reactors of the Fukushima BWR (Boiling Water Reactor), where the moderator and coolant used is the same water.
In Chernobyl accident led to an imperfect project and several human error, which was not qualified. Accident in Fukushima has served as a natural disaster. If an earthquake the Japanese nuclear power plant has resisted, then later the tsunami was the verdict of fate.
In Chernobyl, the test procedure has led to explosions that occurred in the reactor. As a result, a large amount of nuclear fuel was scattered around, there was a fire of graphite, a large amount of radioactive particles on the air resounded. Vytsyakanne radiation continued until the construction of the sarcophagus.
At the time of the earthquake in Japan, all three operating reactors of Fukushima have been stopped with a safety system. However, later the tsunami destroyed power and cooling. Explosions and fires have occurred as a result of a chemical reaction, the reactors damaged reinforced concrete shell, but not the reactors themselves.
After Chernobyl, the diagnosis of acute radiation sickness was put 134 employees and a fire station. Dozens have died in the first months after the accident. By the Chernobyl Forum, which operates under the auspices of the UN, the victims of cancer caused by the accident, were from 4 to 9,000 people.
In Fukushima, as a result of wounds two officers were killed, several the man wasand are hospitalized due to the high levels of radiation.
After the Chernobyl accident in the evacuated Ukrainians was recorded average level of 17 mSv (milizyvertav), the Belarusians 31 mSv. Some liquidators were exposed to 500 mSv of radiation. Japanese nuclear control reported that 20 staff station received doses of 100 to 180 mSv.
The town of Pripyat, where 50,000 people lived, was completely evacuated within 36 hours after the accident. Later, a 30-kilometer zone around the plant have been evicted about 70,000 people. According to the IAEA, entirely due to the accident place of residence changed about 350,000 people, including 135,000 in Belarus.
With the 20-kilometer zone around Fukushima was evacuated almost 80,000. Preparing for the evacuation zone from 20 to 30 km, because, according to the Japanese authorities, the annual radiation exposure when staying here would be 20 mSv or more.
Contamination of the territory
Some European experts (Dana shot, Czech Republic) believe that the level of radiation in Fukushima vytsyakannya ten times less than Chernobyl. Most of the leaked radiation in Fukushima heading into the ocean and on its surface. Such a level that today zamyarayutstsa immediately around Fukushima, recorded hundreds of kilometers from Chernobyl. After Chernobyl were contaminated by radiation over 200,000 square meters. kilometers of European territory, including 150,000 square kilometers in Belarus, Ukraine and Russia.