Greg's right on that.
Having repaired and rebuilt breakers all the way up the 15kV ones I can confirm that a circuit breaker is basically just a knife switch with tons of stuff to make it move quickly and a fair amount of stuff to snuff out the arc that is created at the moment that the breaker opens. Once it has opened, it's dead and harmless (unless there are charged springs in it waiting to break an unwary finger).
