The big question answered: Who gave TEPCO permission to use plutonium at the Reactor #3, when was permission granted, and why? : Japan Subculture Research Center

Thanks to contributions from readers, and some hours of research, I found the answer to the question originally posed here (see original article below). The current governor of Fukushima Prefecture, Sato Yuhei, was the one who unilaterally gave TEPCO permission to use plutonium mixed fuel (MOX) in the Fukushima reactors in August of 2010. One of the conditions for granting permission was that the nuclear reactors be made more quake resistant. Obviously, that condition didn’t seem to have been met. Tsunamis (tidal waves) are often produced by earthquakes. It would seem logical that any plans to make sure that the reactors could withstand an earthquake would also factor in tsunami as well. But maybe I’m being nit-picky