CORFU, Greece -- The European Union has said it is ready to pump 500 million European currency units ($600 million) into an international nuclear-safety plan for Ukraine that would shut Chernobyl, site of the world's worst nuclear accident in 1986. EU leaders said Saturday they were willing to provide the money as part of a comprehensive scheme to be discussed at the summit of the Group of Seven leading industrialized nations in Naples on July 8-10. Under the EU plan, the union would raise 400 million ecus in European Atomic Energy Community loans and 100 million ecus in grants from the EU's technical assistance program for countries of the former Soviet Union.