Robuta

https://www.tepco.co.jp/en/press/corp-com/release/11070306-e.html

https://www.tepco.co.jp/en/press/corp-com/release/11080807-e.html

https://www.taylorfrancis.com/chapters/edit/10.1201/9781420041392-6/radioactive-materials-ionizing-radiation-sources-radioluminescent-light-sources-nuclear-batteries-kavetsky-nekhoroshkov-meleshkov-kaminski-akulov

https://www.tepco.co.jp/en/press/corp-com/release/11042810-e.html