Workers in Japan started releasing treated radioactive water from the Fukushima Daiichi nuclear power plant into the Pacific Ocean on Thursday. Reactors at the plant began melting down after a 2011 earthquake and tsunami that hit the area. To stop the meltdown, plant workers flooded the reactors with water. But even now, when the plant is offline, the reactors need to be cooled. All that water—about 350 million gallons—is being stored on-site in over 1,000 tanks. And now, these tanks are almost full. Today on the show, host Regina G. Barber talks to NPR reporters Geoff Brumfiel and Kat Lonsdorf about the official plan for the radioactive wastewater, the science behind the release and why some are unhappy about it. What science story do you want to hear next on Short Wave? Email us at shortwave@npr.org.