You didn't specify what you mean by "Us"...
But judging by your location, India.. I'd say no, it's not really a threat to anyone else but japan at the moment... And also the wind direction is the other way.. towards america, but by the time the wind that is in japan reaches america, there will not be any radiation in the atmosphere left.
If you're talking about nuclear powerplants in general.. no, they are not a danger, as long as they are built correctly and the engineers dont **** up.
When the ones in japan were built, the japanese government was warned that the powerplants could fail if a big earthquake hit japan (Now I don't know if this is true, but thats what they said in the papers). Now that is the engineers fault, they didn't make it safe enough.
Nuclear power is the most efficient and cleanest way of getting energy.
So when building a powerplant, it is very important that they build it safe so that the same thing doesn't happen anywhere else in the world.