Just a day before Christmas Eve—on December 23, 2025—workers at the decommissioning site of Japan’s Fugen advanced converter reactor in Fukui Prefecture noticed a tiny water leak containing tritium, a radioactive isotope of hydrogen ☢️💧.
According to the Japan Atomic Energy Agency (JAEA), the leak occurred shortly after 3 p.m. Three staff were on site, but thanks to quick response and safety gear, no one faced internal or external radiation exposure. There’s also no sign of impact on the surrounding environment 😌.
JAEA confirms that about 20 milliliters of tritium-contaminated water escaped from a pipe during dismantling work. The team immediately stopped the leak and notified the Nuclear Regulation Authority when tritium levels inside the demolition zone exceeded regulatory limits.
Monitoring posts around the site detected normal radiation levels, underscoring the effectiveness of ongoing safety measures. Even though decommissioning is a complex process, this incident shows Japan’s rigorous oversight remains in full swing 🔧✅.
The Fugen reactor served as a research facility for the government’s nuclear fuel recycling policy. It ceased operation in 2003 and has been undergoing decommissioning since 2008, part of Japan’s broader efforts to responsibly retire aging nuclear sites.
Reference(s):
Radioactive water leak at decommissioned nuclear reactor in Japan
cgtn.com
