South Korea on Saturday, April 4, 2026, successfully restarted one of its oldest nuclear reactors, marking a significant step in the country’s efforts to maintain energy security while upholding strict safety standards.
The state-run operator Korea Hydro & Nuclear Power Co. confirmed that the Gori-2 reactor had resumed operations after being offline for nearly three years, according to reports by Yonhap News Agency. The restart occurred at the Gori Nuclear Power Plant in the southeastern coastal city of Busan, where the unit has long served as a key part of South Korea’s nuclear infrastructure.
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Gori-2 was first commissioned in 1983 as South Korea’s third nuclear reactor. It played a vital role in the country’s early nuclear energy development, helping to power industrial growth and reduce reliance on imported fossil fuels during a period of rapid economic expansion. With a capacity of approximately 640 MWe, the pressurized water reactor contributed substantially to the nation’s electricity supply for four decades before its temporary shutdown.
The reactor was taken offline in 2023 when its original 40-year operating license expired. This triggered an extensive regulatory review process that included thorough safety inspections, structural assessments, and comprehensive facility upgrades to meet modern regulatory standards set by the Nuclear Safety and Security Commission (NSSC). The upgrades focused on enhancing seismic resilience, improving emergency cooling systems, strengthening containment structures, and incorporating the latest advancements in nuclear safety technology. Specific improvements included design changes to accident management facilities, such as the reactor coolant external injection path, and the installation of facilities to supply power to essential accident response equipment.
Regulators granted final approval for the reactor’s restart late last year after confirming that all required safety enhancements had been successfully implemented and verified through rigorous inspections. The restart process involved careful testing of systems and a gradual power ascension to ensure stable and safe operations before full integration into the national power grid. The NSSC had earlier approved the continued operation of the unit until 2033, allowing the reactor to run for another decade following the upgrades.
The return of Gori-2 to active service is seen as an important development for South Korea’s energy mix. Nuclear power remains a cornerstone of the country’s electricity generation, supplying a substantial portion of its baseload power needs. With limited domestic fossil fuel resources and growing demand for stable, low-carbon energy to support its high-tech industries, the government has continued to emphasize the importance of nuclear energy. This approach comes while maintaining a strong commitment to safety, informed by past global nuclear incidents that heightened public awareness and regulatory scrutiny.
The decision to restart the aging reactor reflects a careful balancing act between energy security, economic considerations, and public safety concerns. South Korea operates one of the world’s most advanced nuclear fleets, and the successful extension of Gori-2’s operational life demonstrates the country’s technical capability to safely manage older reactors through rigorous modernization programs. This milestone is particularly notable as it represents the first nuclear power plant unit in the country to resume operations after fully implementing post-40-year license safety improvements.
Local residents near the Gori plant, many of whom have lived alongside the facility for decades, have expressed mixed reactions. While some welcome the restart for its contribution to stable electricity supply and potential economic benefits for the Busan region, others continue to voice concerns about the risks associated with operating older nuclear infrastructure, even after extensive upgrades. Environmental groups and some opposition voices have called for greater transparency and public consultation regarding the operation of aging reactors. They argue that while safety upgrades are essential, South Korea should accelerate its transition toward renewable energy sources to complement nuclear power and reduce long-term risks.
Korea Hydro & Nuclear Power Co. has assured the public that the reactor now meets or exceeds current international safety benchmarks. The company stated that continuous monitoring systems, regular inspections, and advanced early-warning mechanisms will be in place to ensure safe and reliable performance throughout the extended operational period. Officials from the Ministry of Trade, Industry and Energy have emphasized that all nuclear operations in South Korea are conducted under strict oversight by independent regulatory bodies. They noted that the successful restart of Gori-2 reflects years of meticulous planning and investment in safety infrastructure.
The restart comes at a time when South Korea is navigating broader energy challenges, including fluctuating global fuel prices, efforts to reduce carbon emissions in line with international climate goals, and the need to support its high-tech industrial sector that demands consistent and affordable power. Nuclear power is expected to continue playing a central role in the country’s long-term energy strategy, with plans for new reactors and the life extension of existing ones being carefully evaluated alongside investments in renewables.
As the reactor gradually ramps up to full capacity, engineers will continue to monitor performance indicators closely. The Gori Nuclear Power Plant, which includes multiple units, remains one of the most significant energy facilities in the Busan region, contributing substantially to the country’s overall electricity generation. The development is likely to be welcomed by industries that depend on reliable and cost-effective power supply. At the same time, it underscores South Korea’s ongoing commitment to maintaining a robust nuclear program even as it explores diversification of its energy sources.
With Gori-2 now back online, attention may shift to other aging reactors in the country’s fleet that are approaching the end of their original licenses. Similar safety upgrade and license extension processes are expected to be carried out in the coming years to ensure continued energy stability. The successful restart of this historic reactor highlights the technical expertise and regulatory rigor that South Korea has developed in the nuclear field over the past four decades.
It also serves as a reminder of the complex trade-offs involved in energy policy, where safety, reliability, economic growth, and environmental considerations must all be carefully weighed. As operations resume at Gori-2, both the operator and regulatory authorities have pledged to maintain the highest standards of safety and transparency to sustain public confidence in the country’s nuclear energy program. This event signals a continued focus on extending the life of proven nuclear assets while preparing for future energy transitions in one of Asia’s most technologically advanced economies.
