August 10, 2025

A colorful splash on the global ocean canvas! The Fukushima Daiichi Nuclear Power Plant, famous from the 2011 disaster, has been releasing treated radioactive wastewater into the Pacific slowly over years. But how far and how dangerous is this tritiated water? Until now, research focused only near Japan’s coasts. Exciting new research by University of Tokyo and Fukushima University scientists offers a dazzling full view. They created a powerful ocean model named COCO 4.9 that tracks how this radioactive tritium drifts through the vast, warming Pacific Ocean. Here’s the experiment: They first ‘injected’ a dose of tritium matching the 2011-2019 disaster spike at the ocean’s surface. Then they mimicked the future – a huge 480 terabecquerels released slowly from 2023 to 2051 just below the surface, the maximum expected from the Tokyo Electric Power Company. Next, they challenged their model with three wild scenarios: today’s ocean, a fiery hot future path called SSP5-8.5, and the twisting dance of small ocean whirlpools called eddies. What’s the verdict? Across the mighty Pacific, tritium levels never crossed the tiny detection threshold, except right next to Fukushima during the disaster spike. The routine releases remained 25 times lower than natural background radiation! The warming world seems to shift the important Kuroshio Current slightly north and speeds up eastward flow, making tritium reach mid-Pacific and Asian coasts about 3 years earlier. Yet, even then, tritium remains buried three orders under safety limits. Interestingly, tiny amounts might travel sooner to Western North America or the South China Sea, thanks to swirling eddies. But even this does not raise any health alarms. Remember, tritium’s half-life is about 12 years—it fades away naturally. Because its steady discharge is so gentle, natural radiation remains far stronger than Fukushima’s contribution. The researchers found that their model shows no detectable tritium in the wider Pacific through 2099, even under extreme warming or worst-case ocean mix-ups. These remarkable findings, shining light on ocean safety and nuclear waste, will be published in Marine Pollution Bulletin in November 2025. So, next time you hear about Fukushima’s water, remember: the Pacific Ocean’s vastness and currents are powerful allies in keeping us safe!

Read More at Thehindu →

Tags: Fukushima, Tritiated wastewater, Pacific ocean, Radiation, Ocean currents, Climate change,