South Korea's KSTAR fusion device sustains 100 million degree plasma for 102 seconds, a step toward clean energy

South Korea's KSTAR fusion reactor held plasma at 100 million degrees Celsius for 102 seconds, breaking its own 2024 record. The device uses a tungsten wall configuration that reduces tritium retention issues. While fusion power is still years from commercial use, each sustained run brings researchers closer to a carbon-free energy source that could eventually supply baseload electricity without emissions or long-lived radioactive waste. The Korea Institute of Fusion Energy achieved this by switching from carbon to tungsten plasma-facing tiles, improving stability. The next target is 300 seconds of sustained fusion temperatures. For now, KSTAR does not generate electricity, but the data helps engineers design future reactors. Fusion remains a long-term play for deep decarbonization, but milestones like this show measurable technical progress.