South Korea has authorised the operation of the Saeul 3 nuclear reactor located in the southeastern city of Ulsan, according to a statement by the Nuclear Safety and Security Commission. The commissioning will begin with a six-month test phase, after which the reactor is expected to move into full operation. With an electric output of 1,400 megawatts, Saeul 3 forms part of the country’s long-standing nuclear development programme.
A project launched in 2016
Construction of the reactor began in 2016. The site is operated by Korea Hydro & Nuclear Power, the state-owned company responsible for South Korea’s entire nuclear fleet. Saeul 3 joins an existing network of 26 nuclear units, with three additional projects currently under construction. According to the operator, the reactor has been designed to meet the country’s latest nuclear safety standards.
Nuclear at the core of the energy mix
According to the South Korean Ministry of Industry, nuclear accounted for 31.7% of national power generation in 2024, ahead of natural gas and coal, each at 28.1%. These figures highlight the strategic role of nuclear energy in the country’s power mix, aiming to balance supply security with energy independence. The development of new capacity is intended to meet rising demand while reducing fossil fuel imports.
A tense regional context
The announcement comes amid heightened geopolitical tensions between North and South Korea, particularly concerning their respective nuclear capabilities. South Korean authorities did not link the authorisation directly to the security context, but strengthening national energy infrastructure remains a long-term strategic priority. The country’s nuclear fleet today constitutes a major element of its energy policy.
