TOKYO (AP) — A nuclear watchdog has asked the operator of Japan’s wrecked Fukushima nuclear plant to assess possible risks resulting from damage that was found in a key supporting structure inside one of the three melted reactors. The damage, which was found by a robotic probe in March, triggered concerns about the reactor’s safety. It was the first time a robot was able to access the area and take pictures. The damage is believed to be from the initial earthquake in 2011, but might have happened more recently. The Fukushima Daiichi plant is preparing to release treated, but still slightly radioactive, water into the sea. The release has triggered protests from the local fishing community and neighboring countries.