Zaporizhzhia Nuclear Plant Complete Shutdown..."Transitioning to Safe State" (Comprehensive Report 2)

"Final Reactor Power Grid Shutdown Cold and Hot Shutdown"
Repeated Bombardment Leaves Europe's Largest Nuclear Plant Still 'Unstable'

Zaporizhzhia Nuclear Power Plant in Ukraine. (Image source=Reuters Yonhap News)

[Asia Economy Reporter Moon Chaeseok] Ukraine's state nuclear operator Energoatom announced on the 11th (local time) that the operation of the Zaporizhzhia Nuclear Power Plant (ZNPP), the largest nuclear power plant in Europe, has been completely halted.

In a Telegram statement, Energoatom said that at 3:41 a.m. that day, the power grid connection of the last operating reactor, Unit 6, at the Zaporizhzhia plant was cut off, adding, "ZNPP has come to a complete stop." It also added that preparations are underway to switch Reactor 6 to a "cold shutdown" state. Cold shutdown means the reactor temperature is maintained below 100 degrees Celsius, indicating a stable condition.

According to Energoatom, after the last transmission line connecting ZNPP to Ukraine's national power grid was severed by a Russian attack, Unit 6 was isolated from the power grid. Accordingly, Unit 6 operated in "island mode" for the past three days, producing only the power necessary to maintain the safety of the plant, including self-cooling. Then, with the restoration of the severed transmission line, ZNPP was able to receive external power necessary for safety without operating Unit 6. Energoatom explained, "We decided to stop Unit 6 and switch it to the safest state, cold shutdown." The International Atomic Energy Agency (IAEA) also reported on Twitter that "With the restoration of the power line, ZNPP can now receive power from the grid."

Although the last reactor, Unit 6, has been safely stopped, concerns about a nuclear accident at ZNPP persist. ZNPP is the largest nuclear power plant in Europe. There are even estimates that in the event of an accident, the damage could surpass that of Chernobyl. While the reactor itself, where the nuclear reaction occurs, is designed to withstand some impact with reinforced concrete and other materials, the problem lies in the vulnerability of the power supply facilities to attacks. The facilities supplying power to the reactor lack special protective measures.

If power supply is cut off due to an unexpected accident before the reactor is sufficiently cooled to the "cold" state, a meltdown could occur, potentially leading to a radioactive material leak disaster. The "island mode," in which the reactor produces its own cooling power, is explained by the Associated Press as insufficient to guarantee safety.

Energoatom said there is a high risk that the currently connected transmission line could be damaged again, stating, "If it is damaged again, we will have no choice but to operate diesel generators to maintain safety. How long emergency power can last depends on fuel reserves and the availability of technical resources." Energoatom told the AP that the current stockpile of fuel for power generation is only enough for 10 days.

The spent nuclear fuel cooling pools are also vulnerable to shocks. Spent nuclear fuel emits strong radiation for a certain period, and if it leaks outside the storage facility, it could cause great danger. Despite this, shelling around ZNPP continues unabated. Ukraine and Russia are blaming each other for the attacks and demanding a halt to the fighting.

Even after the IAEA inspection team visited the Zaporizhzhia plant following an agreement between Ukraine and Russia, the risks continue. The IAEA pointed out that the local situation is increasingly precarious as the plant’s power grid connection has been repeatedly cut and restored. On the 7th, citing local accident risks, Ukrainian authorities issued an evacuation order for residents near ZNPP. Ukrainian President Volodymyr Zelensky has demanded that the area around the Zaporizhzhia plant be designated a demilitarized zone.

Russia occupied the Zaporizhzhia plant in March this year, shortly after invading Ukraine, but Ukrainian staff continue to operate the plant.

This content was produced with the assistance of AI translation services.