Nuclear energy: Where next?

As the world accelerates its transition toward a carbon-neutral future, the demand for clean, reliable, and sustainable energy sources is intensifying. Nuclear energy stands out for its high energy density and near-zero carbon emissions. According to the International Energy Agency, it provides about 10% of global electricity and is expected to play a crucial role in achieving net-zero emissions. Yet its long-term sustainability depends not only on operational safety, but also on resource security and environmental responsibility.

Uranium resources and supply challenges

Today, nuclear energy predominantly relies on the fission of U-235, which has supported stable electricity generation for decades. Yet land-based uranium resources are both limited and geographically concentrated, with Australia, Kazakhstan, and Canada together producing nearly two-thirds of the world’s uranium (World Nuclear Association). These reserves, totaling roughly 8 million tons, are estimated to support global nuclear power generation for only about 70 years (International Atomic Energy Agency and Nuclear Energy Agency). With such limited availability, the planned global expansion of nuclear capacity underscores the urgent need to diversify fuel sources beyond conventional land-based uranium.

Diversified resource strategies

To address these constraints, researchers and industry stakeholders are actively exploring diversified strategies to enhance the sustainability of nuclear fuel cycles. These efforts aim to expand uranium availability while improving energy security and reducing environmental and geopolitical risks. Key strategies include seawater uranium extraction, thorium-based fuels, and transmutation of long-lived radionuclides, together with improved spent fuel management.