Officials have two contradictory explanations about the cause of the accident. The first article was published in August, 1986, which completely shifted the responsibility for the accident to the nuclear power plant operators. The second paper, published in 199 1, explained that the accident was caused by the design defects of pressure tube graphite moderated boiling water reactor (RBMK), especially the design of control rods.

The investigation teams of both sides were lobbied by many parties, including reactor designers, Chernobyl nuclear power plant staff and the government.

Another important factor contributing to the accident was that the staff did not receive the report about the reactor problem. According to employee Anatoli Dyatlov, the designer knew that the reactor was dangerous in some cases, but deliberately concealed it.

Extended data:

Radioactive dust leaked from the melting of atomic furnaces drifted over Russia, Belarus and Ukraine, as well as parts of Europe, such as Turkey, Greece, Moldova, Romania, Lithuania, Finland, Denmark, Norway, Sweden, Austria, Hungary, Czech Republic, Slovakia, Slovenia, Poland, Switzerland, Germany, Italy, Ireland, France (including Corsica) and Britain.

1on April 27th, 986, the staff of Forsmark nuclear power plant in Sweden found abnormal radiation particles stuck on clothes. The power plant is about1100km away from Chernobyl. According to Swedish research, it is found that radiation does not come from local nuclear power plants, and they suspect that there is something wrong with Russian nuclear power plants. At that time, Sweden asked the Soviet Union through diplomatic channels, but it was not confirmed.

In addition, the French government claimed that radioactive dust only drifted to the border between Germany and Italy. Because of radioactive dust, Italy stipulates that some crops are forbidden to people, such as mushrooms. In order to avoid causing public fear, the French government did not conduct similar measurements.

The Chernobyl disaster not only polluted the surrounding towns and villages, but also was helped by the airflow, so it could spread irregularly. According to the reports of Russian and western scientists, 60% of radioactive dust falling from Russia is in Belarus.

According to the report of Torch 2006, half of volatile particles fall outside Ukraine, Belarus and Russia. A large area in southern Bryansk, Russian Federation, and parts of northern Ukraine have been polluted by radioactive materials.

Reference source: Baidu Encyclopedia-Chernobyl Incident