"I'm changing the fire extinguishing system of the nuclear power plant".an all-talking KHNP.

[Anchor]
YTN reported two years ago that the fire extinguishing facilities of "emergency diesel generators" that supply power in the event of an emergency at a nuclear power plant are vulnerable to risk preparation.

Korea Hydro & Nuclear Power (KHNP) acknowledged the risks and said it would change its design, but it is still lagging.

Further claims have been made that the facility is also vulnerable to typhoons and earthquakes.

I'm reporter Jang A-young.

[Reporter]
Fire extinguishing facilities that emit carbon dioxide in dry ice with fire alarms, and indoor temperatures drop to minus 50 degrees in two minutes.

It can extinguish the fire faster and cleaner than water, but it is not suitable for emergency diesel generators in nuclear power plants.

Diesel generators are designed to withstand 10 to 50 degrees, and minus 30 degrees is the limit even when held wide.

There is also a concern of suffocation, and the accident in the power generation room in Geumcheon-gu, Seoul, where four people died in 2021, was also caused by a leak of carbon dioxide for extinguishing the fire.

Earlier, Korea Hydro & Nuclear Power also acknowledged this and said it is changing its fire facilities from carbon dioxide to water spraying.

[Hwang Joo-ho / President of Korea Hydro & Nuclear Power (National Audit on October 19th last year): If we use CO2 and CO2, suffocation accident can occur, so we are changing to handling fire with water. (Have you ever tested at minus 50℃?) I've never done anything like that.]

However, contrary to what was said, a year later, the YTN report confirmed that it has not applied for permission to change operations to the Nuclear Safety and Security Commission.

Of the 26 nuclear power plants in operation nationwide, a total of 16 nuclear power plants use automatic carbon dioxide extinguishing facilities.

Construction is underway after changing to water from Saeul Units 3 and 4, which were approved for construction with carbon dioxide, but 16 units remain the same.

Fire extinguishing is not the only flaw these nuclear power plants share.

In the United States, the 'ventilation' of fuel tanks, which has been defined as a 'safety level' since 1979, and in Korea, it has been classified as an 'non-safety level' since 1989.

It has also changed to non-safety class from Hanbit 3 and 4 units, which Korea led the design.

The ventilation pipe that allows air to flow is outside the building, but there is currently no protective or earthquake-resistant design to prevent objects flying in from typhoons.

If the ventilation pipe is distorted by an earthquake or typhoon, there may be an abnormality in the fuel supply pump.

[Jung Jong-han / Nuclear Power Technician: If the ventilation engine fails when the tank's oil level goes down due to fuel supply, a vacuum will enter the tank, causing the tank to shrink like a can, and the pump to fail. In the event of an earthquake set by design standards, all diesel generators become useless due to the loss of ventilation in all areas, and the reactor core can melt down like the Fukushima nuclear accident.

KHNP explains that there is no problem because the ventilation engine does not deliver fuel directly, and even if it is damaged, air can pass through the other side.

However, nuclear power plant experts refute this.

[Kim Hae-joo / Former head of Doosan Heavy Industries & Construction's reactor facility design management team: If that's the logic, there's no need for a ventilation system. Isn't it necessary to breathe when the fuel goes up and down? It's a ventilation tube that allows air to flow in and out freely.]

Another problem is that once the design is completed, the nuclear power plants to be built later replicate the same design one after another.

Korean nuclear power plants exported to the UAE and nuclear power plants that have recently been exported to the Czech Republic are also based on the same design.

[Lee Jung-yoon / CEO of Nuclear Safety: Why are you covering up minor matters? All accidents start from minor points.... / KHNP has the first priority and most important obligation to operate a power plant safely. How can it operate a power plant like this just because it exports nuclear power plants?.]

Of the 400 nuclear power plants in operation around the world, 26 are concentrated on narrow Korean soil, but the government plans to build at least seven more by 2038.

With earthquakes occurring on the Korean Peninsula more frequent and stronger, and all-time heavy rains and typhoons frequent due to the climate crisis, nuclear power plant authorities' perception of "what if" still seems easy.

I'm YTN's Jang Ayoung.


Video editing: Lee Young-hoon
Design: Kim Jin-ho