...let's first realize that San Diego is a MILITARY town, with lots and lots of [conventional and nuclear-powered] U.S. Naval ships and lots and lots of Naval and Marine aircraft all over the place.  So the likelihood that there are and have been nuclear-type materials stored there [or in the immediate area] for years is a fair guess.

http://theintelhub.com/2011/02/12/port-officer-says-nukes-have-been...

Second, if "unnamed sources" can't be named, then it's a foregone conclusion that the 'story' is just that - a story, and one probably designed to do nothing more than excite and distract for other gains.  This 'story' highly smacks of that.

And third - it would be completely logical (if I can use that word) to expect that in every major city of the world, there are already well-placed 'devices' as set there by each others governments as a 'mutual deterent' lest any one government ever think it's going to take over the world.  It's called MUTUALLY ASSURED DESTRUCTION - M.A.D. for short (and that's really a perfect acronym given the mindsets of the insane people who think they rule everybody else.)

So don't go frothing at the mouth and expecting to see mushroom clouds all over the U.S. anytime soon.

However...dispersement of chemical and/or biological weapons in major cities....well, that's a whole 'nuther matter and the format we should really be preparing ourselves for.  (And yes, gas masks could well become 'the thing' to wear this coming fashion season.)