I think if some type of nuclear weapon had been found, it would have been pasted on the evening news by every alphabet channel in the country as verfication of terrorists possessing WMD.
I would take it with a grain of salt until some official type of corroboration appears, but we all know the Gov seems to reject labeling anything as terrorist related.
I think if they found a nuke they would try very hard to squelch that info and keep it from media release...I suspect there are certain possible news stories that have to be "cleared through channels" for national security reasons or an airwave sword of damocles will descend promptly. We will read of it first...and the webpage easily might vanish.
I dont know about the media. Considering the snippet said it found ONE, not ALL. It was on a timer and it was ticking already (according to the orginal brief).
That being said, if there are others in other cities, or the same city, the clock is still ticking on them.
By releasing info that we found one and not all and that the clocks are still going on the others would send that city or others into a panic. So I doubt they would release that information unless they were sure they got them all.