Wolsong nuclear power plant Unit 4 (far left). [Provided by Wolsong Nuclear Power Plant Headquarters]
Wolsong nuclear power plant Unit 4 (far left). [Provided by Wolsong Nuclear Power Plant Headquarters]

Heavy water leaked into a sump inside the reactor building at Wolsong Unit 4, a 700,000-kilowatt pressurized heavy-water reactor currently undergoing scheduled preventive maintenance.

According to Korea Hydro & Nuclear Power's Wolsong Nuclear Power Plant Headquarters, the leak was detected Tuesday at around 2:26 p.m. during the transfer of heavy water for ion-exchange resin replacement in the heavy-water purification system. An equipment malfunction caused the spill, and 208 kilograms of heavy water were recovered.

"We have confirmed that the leak has had no impact on the external environment, including radiation," a Wolsong headquarters official said, adding that the plant plans to identify the cause of the equipment malfunction and take corrective action.


kbj7653@heraldcorp.com