https://www.nytimes.com/2017/11/19/science/japan-fukushima-nuclear-meltdown-fuel.html Daisuke Hirose, a Tepco spokesman, inside the Unit 5 reactor at the Fukushima nuclear power plant. Tepco used underwater robots that finally found the melted uranium fuel inside Unit 3, another reactor that was destroyed.Credit...Ko Sasaki for The New York Times