Ageing nuclear reactors could complicate global capacity expansion plans: IAEA

An ageing global nuclear reactor fleet could pose challenges to future capacity expansion, as countries may need to invest in extending the operational lives of existing plants while simultaneously building new reactors, according to the International Atomic Energy Agency's (IAEA) Nuclear Technology Review 2026.

An ageing global nuclear reactor fleet could pose challenges to future capacity expansion, as countries may need to invest in extending the operational lives of existing plants while simultaneously building new reactors, according to the International Atomic Energy Agency's (IAEA) Nuclear Technology Review 2026. The report highlights the growing importance of reactor maintenance, refurbishment and life-extension programmes as countries seek to expand nuclear power generation to meet rising electricity demand and strengthen energy security.

"About 67% of global nuclear power capacity (293 reactors, 263.9 GW(e)) has operated for over 30 years, and 41% (190 reactors, 135.5 GW(e)) for more than 40 years," the IAEA stated in its annual review. The findings indicate that future nuclear capacity growth will depend not only on commissioning new reactors but also on maintaining existing generation capacity as older plants approach decisions on further operation or retirement.

According to the report, global nuclear capacity has remained relatively stable over the past decade, increasing from 370.2 gigawatts in 2016 to 379.9 gigawatts in 2025. During this period, approximately 61.4 gigawatts of new capacity, comprising 60 reactors, was connected to electricity grids worldwide.

Despite the ageing fleet, nuclear power plants continued to maintain strong operational performance. "Despite the ageing fleet, nuclear power performance remained strong, with a global load factor reaching 93% in 2025," the report stated.

However, the number of reactors being shut down for permanent retirement and dismantling has continued to increase. "As of the end of 2025, 218 power reactors in 21 Member States were shut down for decommissioning, with 23 units fully decommissioned," the IAEA said.

The agency also highlighted financial and technical challenges associated with retiring older nuclear facilities, particularly in countries with limited resources. "Challenges remain, however, particularly in countries with limited technical and financial resources, which impacts their ability to execute effective decommissioning strategies," the report noted.

At the same time, countries are pursuing new nuclear projects to meet growing electricity requirements. According to the review, 72 reactors with a combined capacity of 77.2 gigawatts were under construction across 15 countries at the end of 2025.

The IAEA also identified financing, project cost reduction and regulatory standardisation among the challenges facing the expansion of nuclear power. The findings underline the need for countries to balance investment in new reactors with the costs of maintaining existing plants, extending their operating lives and managing facilities approaching retirement. (ANI)