South Korea’s Nuclear Safety & Security Commission (NSSC) said it has completed all the mandatory inspections required before unit 3 at Saeul NPP in Ulju, Ulsan, can proceed to first criticality. NSSC approved the operation of Saeul 3 in December 2025, marking the first operational permit for a new nuclear reactor in South Korea since Shin Hanul unit 2 in September 2023.
NSSC said Saeul 3 has completed pre-operational inspection procedures including all nine inspections that must be carried out before the first reactor criticality. The Commission has reviewed key items required in the pre-criticality stage, including the nuclear fuel loading inspection and high-temperature functional tests. The inspections confirmed that related equipment and functions meet the required standards.
Going forward, NSSC plans to conduct 31 additional follow-up inspections, including power ascension tests after reactor criticality until just before commercial operation. In addition, during commissioning, it will continuously verify that safety systems operate normally and strengthen the emergency response system so that, in the event of emergencies such as accidents or failures, it can respond immediately at the same level as operating nuclear power plants.
