Russian leadership in many areas involving nuclear energy continues, Aleksandr Rumyantsev, who heads the Federal Atomic Energy Service, declared Saturday on Radio Mayak. Russia leads, he said, in production of enriched uranium and in the harvesting of isotopes. He also declared that Russian designs for nuclear generating stations now meet world standards. He also revealed that a design has been produced for the creation of an experimental thermonuclear reactor by an international consortium. 'Intense talks' are now underway, he said, on where it will be built-in Japan or in France.