One of the storage tanks from Japan's Fukushima nuclear power plant damaged by the 2011 earthquake and tsunami has leaked about 300 tons of radioactive water, officials report.
Investigation is ongoing, but Tokyo Electric Power Co. (TEPCO) said the leak may have occurred through a seam on the tank or valve on a surrounding gutter. The radiation is about five times the annual exposure limit for plant workers. TEPCO said seawater contamination is not an immediate concern, because the tank is 330 feet (100 meters) from the coast, but Japan's nuclear watchdog said the leaked water could enter the ocean by a drain gutter, The New York Times reported.
Four other tanks had similar leaks in 2012, but this leak is the worst one yet. Sandbags were piled around to soak up the flow, but radioactive water still soaked into the ground, TEPCO said. Workers are racing to pump the water out of the puddle and tank before the arrival of heavy rain predicted for later in the day.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.