China's HL-3 Achieves 500-Second H-Mode Operation: A Key Step Toward Fusion Commercialization

Another Step Closer to Capturing the Sun

China National Nuclear Corporation today announced that the HL-3 tokamak in Chengdu, Sichuan achieved 500-second high-confinement mode (H-mode) operation in its latest experimental campaign, with plasma temperature reaching 150 million degrees Celsius — approximately 10 times the sun's core temperature. Energy confinement time broke 3 seconds, setting a world record for medium-scale tokamak devices.

Nuclear fusion — merging light atomic nuclei into heavier ones while releasing enormous energy — is the sun's power source and humanity's ultimate clean energy goal. Fuel comes from deuterium in seawater, the product is non-radioactive helium, with no greenhouse gas emissions and virtually no long-lived radioactive waste.

From Seconds to Minutes

The HL-3's 500-second H-mode demonstrates successful management of multiple instabilities during extended operation, including edge localized modes (ELM), resistive wall modes (RWM), and impurity accumulation. Key innovations include advanced divertor configuration, real-time AI feedback control at 1,000Hz, and boron-coated wall treatment.

Global Fusion Race

HL-3's results come at a critical time for global fusion research. ITER in France targets Q=10 by 2035; America's Commonwealth Fusion Systems plans SPARC by 2030. China's roadmap includes the China Fusion Engineering Test Reactor (CFETR) targeting power demonstration by 2035.

How Far From Commercialization

Multiple experts estimate the first demonstration fusion power plant will connect to the grid around 2040, with commercial fusion power reaching scale by the 2050s.