The Chernobyl nuclear accident: an unfinished threat
According to the latest reports, scientists have discovered an alarming phenomenon in Chernobyl. The "Subreactor Room 305/2" area, located southeast of Reactor 4, is tightly sealed by a concrete structure known as the "sarcophagus". Neither humans nor robots can enter this area. However, scientists have detected a sharp increase in the number of neutrons on its periphery, which means that a fission process may be taking place inside.
In the design of the Chernobyl nuclear power plant, uranium-235 was used as nuclear fuel with graphite. The role of graphite as a moderator is to reduce the velocity of neutrons, making it easier for uranium-235 to capture neutrons and produce fission. To control the reaction rate, boron carbide control rods are used to absorb neutrons. When all of these control rods are inserted, the activity of the reactor essentially stops; But if it is completely unplugged, the reaction speed can be uncontrollably fast, leading to catastrophic consequences.
After the accident, in order to plug and suppress the nuclear fission reaction, the former Soviet Union dropped about 2,000 tons of boron carbide and sand by helicopter, and then built a sarcophagus on the reactor, and in order to further strengthen it, the sarcophagus was further reinforced.
But despite all the measures that have been taken, why are there signs of nuclear fission in this blockaded area? The researchers speculate that this may be related to a change in the water level inside the sarcophagus. Although there is a lot of boron carbide and cooling water inside the sarcophagus, the water can evaporate or leak over time. Under certain water level conditions, the velocity of neutrons may be at a "golden point" that can trigger fission.
To solve this new problem, scientists propose to drill holes in the "Subreactor Room 305/2" area, and then inject large amounts of "gadolinium nitrate liquid", which can absorb large amounts of neutrons and hopefully eliminate nuclear fission reactions.
It is worth noting that although the initial cause of the Chernobyl nuclear accident was human error, it was a wake-up call to the world. At that time, an exercise tried to test the ability of the steam turbine to keep the cooling water pump running after it was shut down, but due to a series of faulty operations, the reactor began to spiral out of control, resulting in a catastrophic explosion.
summary
The Chernobyl accident not only reveals the consequences of human error and management deficiencies, but also shows us the continuing threat of nuclear energy. Despite the passage of many years, some parts of the region are still threatened by radioactive materials. This re-emphasizes the importance of respect, proper operation and strict management of nuclear energy. At the same time, we look forward to the continued efforts of scientists to find a safer and more reliable solution to the ongoing nuclear fission phenomenon.