If tsunamis and earthquakes aren't enough to give the Japanese pause about restarting their country's nuclear reactors, perhaps they should consider the islands' active volcanoes. Several of Japan's nuclear power plants are at "high risk" because they are situated in regions that could be affected by lava flows, Business Insurance reported. Hideyuki Ito, associate professor at Iwate Prefectural University, said several of Japan's nuclear power plants are at "high risk" because they are situated in regions that could be affected by lava flows. Although the chances of an eruption within the next several decades are considered remote, even volcano experts can't predict when one may erupt. Japan's 50 nuclear power plants have been offline following the March 2011 tsunami that crippled the Fukushima plant.