How the last reactor at the Zaporozhye NPP is cooled |
The restoration of the backup power line on Saturday allowed for a safer shutdown of the last reactor in operation
of Ukraine The last nuclear reactor at the Russian-controlled Zaporizhzhya NPP was also turned off. The move came after the external power line was restored, allowing the reactor to be safely shut down.
It is reported that the second backup power line has already been reconnected to the NPP.
The risk of accidents at the nuclear power plant, which is the largest nuclear power plant in Europe, was being fought over the lack of electricity coming from outside the plant.
The Ukrainian employees of the Zaporozhye NPP, which has been under the occupation of Russia since March, continued their activities under these stressful conditions. The International Atomic Energy Agency (IAEA) assessed the situation in the area as “dangerous”.
Russia despite its occupation, what happened at the plant, especially its decisions about which reactor to operate and how Ukraine gives This information was announced by the head of the IAEA, Rafael Grossi, at the press conference held on September 12.
Russia and Ukraine they accuse each other of shelling the area. It is reported that as a result of the shooting, the buildings were damaged, and the power lines necessary for fuel cooling in six reactors were broken. However, even when the reactors are subjected to a “cold shutdown”, as they are now, these lines need to operate.
Controlled fission – the heat released by the splitting of atoms in the nuclear fuel in the reactor core turns water into steam. In turn, electricity is obtained as a result of the steam rotating the turbines. An uncontrolled chain reaction can lead to a huge accident like in Fukushima and Chernobyl.
Grossi called for an immediate cessation of fire, as well as official protection of the area around the station to reduce the risk of accidents.
External power lines are necessary for the safe operation of any nuclear power plant. For this reason, nuclear power plants often have several backup external power lines.
Zaporozhye has four ordinary foreign lines. All of them were cut during the war. The station also has three backup power lines. However, they were also either cut or deliberately disconnected from the system at different points. So at the beginning of this month, none of the lines were working.
In the absence of external power lines in Zaporozhye, two options remain: “island mode” and diesel generators. In “island mode”, the reactor operates at low power to power cooling systems and other essential functions. Both diesel generators are designed to operate only for short periods of time.
Operation in island mode can disable vital parts such as turbines and pumps. Diesel generators intended only for emergency situations have very little fuel inside them.
The IAEA said on Sunday in Zaporizhia that “less if necessary 10 full of fuel for daily activities 20 he said that there is a spare diesel generator.
The restoration of the backup power line on Saturday allowed for a safer shutdown of the last reactor in operation.
However, the term “cold shutdown” used by experts is a relative term. This means that the reactor temperature is below the boiling point, but the electric pumps that move water around the reactor core must continue to operate to cool the fuel. The IAEA said this was essential to prevent an accident.