Wedoany.com Report-Aug. 15, On Wednesday, Korea Hydro & Nuclear Power (KHNP) presented plans to the Nuclear Safety and Security Commission (NSSC) in Seoul to upgrade cooling systems at its nuclear power plants to address rising seawater temperatures. The initiative responds to climate-driven increases in sea temperatures approaching the design seawater temperature, the maximum at which reactors can operate safely.

Upgrades have already been implemented at Shin Wolsong units 1 and 2

KHNP reported that it has been incrementally raising the operating limit seawater temperature within safe margins without altering existing cooling facilities. However, to ensure long-term reliability, the company will enhance cooling performance through facility upgrades. KHNP’s analysis indicates that Shin Wolsong units 1 and 2, located in Gyeongju, may reach their design seawater temperature by 2030, followed by Hanbit units 3 and 4 in Yeonggwang in 2031, and Hanbit units 1, 2, 5, and 6 by 2034.

At Shin Wolsong units 1 and 2, KHNP has already increased the plate size of heat exchangers to improve cooling capacity and plans to further raise the operating temperature limit. For Hanbit units 1 through 6, the company intends to replace tubular heat exchangers by mid-2029. Other nuclear plants will undergo cooling performance evaluations to guide mid- to long-term upgrades. KHNP stated: “Based on actual seawater temperature measurements, seawater temperature rise rate research data, etc, we plan to proactively respond by evaluating the expected time when the seawater temperature limit for each nuclear power plant will be reached annually and establishing a seawater temperature prediction system.”

NSSC Chairman Choi Won-ho emphasized the urgency of these measures: “In order to prepare for accelerated global warming, we must quickly improve facilities so that we can fundamentally solve the problem, and we must do everything possible to respond immediately when high sea temperatures are observed.” The NSSC plans to conduct regular inspections to ensure timely implementation of these upgrades.

The Korea Institute of Ocean Science and Technology noted that the East Sea’s average water temperature rose by 8.3°C from 1980 to 2010 and by 1°C from 2021 to 2023, underscoring the need for adaptive measures. KHNP’s proactive upgrades aim to maintain the safety and efficiency of South Korea’s nuclear power infrastructure amid changing environmental conditions.