way that made them inherently unstable but the water boils away and the fuel is uncovered, the reactivity actually increases, so it leads to a runaway reaction and a potential for a larger explosion. that particular failure mode can't happen in this type of reactor here just based on the inherent physics of the design. >> so interesting. general, i think you were touching on this and i wanted to ask more about this. a senior defense official is now saying that the united states is quote unquote deeply concerned about russia's, what russia's intentions are regarding this nuclear power plant. and i heard a former state department official say earlier today calling this, in his view, nuclear blackmail. what does it tell you about putin's next moves? >> well, it is nuclear blackmail, kate, because that plant could be turned off, it could also be damaged in some way, it could be used as a sort of radioactive bomb that would permanently contaminate large forces of ukraine.