southeastern ukraine is the largest in europe, one of the biggest in the world. officials stress that radiation levels have not been elevated, which is good news. ukraine's president, though, offering this condemnation of russia for the attack. >> translator: we contacted our partners, i talked to schulz, i talked to duda, i talked to president biden. we have contacted president rafael grassy, also prime minister johnson, and we warned everyone that no other country other than russia has ever fired on nuclear power units. this is the first time in our history, in the history of mankind the terrorist state now resorted to nuclear terror. >> i spoke earlier with mariana boudrin associated with harvard university's project on managing the atom. here is what she had to say