200 times normal background levels. u.s. officials suspect it was a prototype of a nuclear cruise missiles. you can see it in this video played by russian president vladimir putin at his state of the union last year. i m joined business an expert. jeffrey lewis is the director of the east asia nonproliferation project good to see you, what do you make of this the second explosion and the idea that radiation levels were elevated in russia? well, i think the evidence right now is pretty overwhelming that this was something nuclear in character, probably the nuclear-powered cruise missiles that vladimir putin showed off, as you said, during his state of the union address. it s not clear how much radiation was released, but this is a serious accident.