More than 13 years after the catastrophic nuclear disaster at Fukushima, Tokyo Electric Power Co. (Tepco) has commenced the challenging task of removing melted nuclear fuel from the bottom of one of the damaged reactors.

Finnish utility Fortum announced on Monday that it has successfully begun using nuclear fuel from U.S.-based Westinghouse Electric, aiming to replace its previous supply from Russia.

Bulgaria's sole nuclear power plant on Monday began using atomic fuel produced by the U.S.-based Westinghouse Electric Corporation, a key step as the country shifts away from its reliance on Russian energy, News.Az reports citing AFP.

Bulgaria is going to stop purchasing Russian nuclear fuel, with the material needed for energy production to be supplied to them by either the U.S. or France, News.Az reports citing TVP World.