Watch NHK Documentary Season 20 Episode 12 Online

Recently discovered data show that about a week after the March 2011 disaster at the Fukushima Daiichi Nuclear Power Plant began, emissions of highly radioactive substances suddenly picked up. Records show that the day before the increase began, the plant's operator, Tokyo Electric Power Company (TEPCO), significantly reduced the supply of water meant to cool the crippled reactors, a move that may triggered the surge in emissions. With help from experts and artificial intelligence, we set out to uncover the reason for the cutback, and to further clarify what happened as TEPCO and the Japanese government fought to control the crisis.