“After shutting off the power grid of the last nuclear reactor, it is in a state of cold and hot stop… Measures following the restoration of the broken power line”
Europe’s largest nuclear power plant remains ‘unsettling’ over repeated shelling of Russia and Ukraine
Ukraine’s Zaporiza Nuclear Power Plant (ZNPP), the largest nuclear power plant in Europe, has been completely shut down, Energoatom, the operator of Ukraine’s state-owned nuclear power plant, announced on the 11th (local time).
Energoatom said in a Telegram statement that “ZNPP has come to a complete halt” at 3:41 a.m. on the same day, saying that the last reactor Unit 6 in operation at the Zaporiza nuclear power plant was disconnected from the grid.
He added that preparations are underway to switch the Unit 6 reactor to a ‘cold shutdown’ state.
Cold shutdown refers to a stable state in which the reactor temperature is maintained below 100 degrees Celsius.
According to Energoatom, Unit 6 has been isolated from the power grid since the last transmission line connecting the ZNPP and Ukraine’s national power grid was cut off in a Russian attack.
Accordingly, Unit 6 has been operating in ‘island mode’ for the past three days, producing only the electricity necessary to maintain the safety of the power generation complex, including self-cooling.
Then, as the broken transmission line was restored, ZNPP was able to receive external power necessary for safety without operating Unit 6.
Energoatom explained, “We have decided to shut down Unit 6 and switch to the safest state, cold and hot stop.”
The International Atomic Energy Agency (IAEA) also tweeted, “The restoration of the power line allows the ZNPP to receive power from the power grid.”
First of all, it means that the last reactor unit 6 has been safely stopped, but concerns regarding the nuclear accident at the ZNPP are not going away.
ZNPP is the largest in Europe and one of the ten largest in the world.
There are also observations that the damage might exceed the scale of Chernobyl in the event of an accident.
The reactor itself, where the nuclear reaction takes place, is designed to withstand a certain amount of shock with reinforced concrete, etc., but the problem is that the power supply facilities are vulnerable to attack.
The facility that supplies power to the nuclear reactor has no special protection.
If the power supply is interrupted due to an accident before the reactor is sufficiently cooled to ‘cold and hot’, the possibility of core melting (meltdown) may occur, leading to a catastrophic leakage of radioactive materials cannot be ruled out.
The AP explained that it is difficult to ensure safety in the ‘island mode’, in which the nuclear reactor generates power for its own cooling.
Energoatom said that there is a high risk that the currently connected power transmission line will be damaged once more.
“How long the emergency power generation can sustain depends on fuel stocks and technical resources,” he said.
Energoatom told the Associated Press that the stockpiled oil for power generation is only 10 days’ supply.
The storage tank that cools the spent nuclear fuel rods is also vulnerable to impact.
Spent nuclear fuel rods generate strong radioactivity for a certain period of time and can pose a great risk if they leak out of the storage facility.
Even in this situation, shelling around the ZNPP continues.
Ukraine and Russia are demanding an end to the attack, blaming each other for the attack.
The danger continues even following IAEA inspectors visited the Zaporiza nuclear power plant under an agreement between Ukraine and Russia.
The IAEA pointed out that the local situation is increasingly precarious as the power grid of the nuclear power plant has been disconnected and reconnected several times.
On the 7th, the Ukrainian authorities issued an evacuation order to residents near the ZNPP due to the risk of a local accident.
Ukrainian President Volodymyr Zelensky is calling for a demilitarized zone around the Zaporiza nuclear power plant.
Meanwhile, Russia occupied the Zaporiza nuclear power plant in March of this year, right following the invasion of Ukraine, but Ukrainian employees are in charge of the operation of the nuclear power plant.
/yunhap news
