Not sure what the actual danger would have been if it the practice bomb (I presume inert and the range does not allow live munitions) had hit the plant - or even if the F16 or any aircraft hit it..
Doing some research the plant is built to exceed nuclear reactor containment levels. The building walls are all 1.5 to 2m thick and the waste cells are additionally buried under up to 9m of earth and aggregate. That thickness of wall is designed to absorb the impact of a crashing jet, it should somfortably handle such an impact.
Doubtless some elements of the press will pick up the story and make a near disaster out of it, and the safety design will be ignored.