South Korea's nuclear power output has exceeded its target as maintenance disruptions, new plants are operating and reactors are reaching full capacity, reducing costs and coal consumption.
Data from Korea Electric Power Corp (KEPCO) showed nuclear generation rose 8.7% in the first half of 2025, three times the annual target of 2.9%, while coal output fell 16%.
A spokesman for the Korea Power Exchange (KPX) said the lowest cost of power generation was achieved through nuclear, lower than coal and liquefied natural gas (LNG).
The KPX spokesman also said that if nuclear and renewable energy continue to expand, generation from gas and coal is expected to decline in the future.
South Korea is the second largest nuclear power producer in Asia after China, which is ramping up nuclear generation, while Japan is reopening old plants and India is starting up new reactors.
The country also currently operates 26 nuclear reactors with a capacity of 26.05GW and is building four more, including two units totaling 2.8GW that are expected to be operational by 2026.
According to KEPCO data, nuclear power is set to increase to 31.7% in 2024 from 25.9% in 2019, offsetting a decline in coal use from 40.4% to 28.1% over the same period.
