Reuters cited Korea Hydro & Nuclear Power spokesman as saying that the Kori No.2 reactor’s operations suspension will ensure the safety in the Busan city, which is more than 300km southeast of Seoul.

The spokesman said: "Rain overflowed to a building designed to collect seawater and cool steam from a turbine.

"This suspension is to ensure safety, although the building is not a core part of the nuclear power plant."

Yonhap News Agency quoted Korea Hydro & Nuclear Power as saying: "As excessive water flowed into a building that takes in seawater to cool down turbine steam, we decided to manually halt the operation of the nuclear reactor for the safety of the electrical equipment.

State-run utility Korea Electric Power (KEPCO) fully owns Korea Hydro & Nuclear Power.

The country has 23 nuclear reactors, which meet one third of the country’s energy requirements.