This is not directly related to Kumamoto but to Japan in general and the use of nuclear power when operators go "Whoops!" The sarcophagus covering the Chernobyl disaster site has been moved into place. The article states, "Ukraine’s president, Petro Poroshenko, speaks at a ceremony celebrating the construction of the shelter" - though "celebrate" may be an inappropriate word here. The Sendai Nuclear Power Plant in Kagoshima, just south of Kuamamoto, is currently the only operative nuclear facility in Japan.
https://www.theguardian.com/world/2016/nov/29/chernobyl-nuclear-disaster-site-covered-with-shelter-prevent-radiation-leaks-ukraine
Chernobyl disaster site enclosed by shelter to prevent radiation leaks
Ukraine plant reactor, scene of worst nuclear accident in history in 1986, covered with airtight structure after years of work