Korea Hydro & Nuclear Power Wolsong Headquarters Resumes Operation of Unit 4... 154-Day Planned Preventive Maintenance Completed

Regular Inspection of 92 Items... Compliance with Safety and Reliability Standards

Wolsong Headquarters of Korea Hydro & Nuclear Power (KHNP) announced on the 23rd that Wolsong Unit 4 (pressurized heavy water reactor, 700,000 kW class), which had entered its 20th scheduled preventive maintenance on April 20, resumed power generation at 4:01 a.m. on the 21st after completing 154 days of maintenance, and reached normal operating output at 1:43 a.m. on the 22nd.

KHNP Wolsong Nuclear Power Headquarters.

Wolsong Unit 4, a nuclear power plant that has achieved a total of 15 cycles of One Cycle Trouble Free (OCTF) operation, carried out maintenance and facility improvement work on major equipment during this scheduled preventive maintenance period, including a comprehensive leak rate test of the reactor building and replacement of the turbine control system equipment.

In addition, as required by the Nuclear Safety Act, 92 periodic inspections were conducted, confirming that the safety and reliability of the reactor and related facilities met the licensing standards set by the law.