A similar test was staged in June, shortly after the plant's parent company had replaced all 42 emergency warning sirens in the 10-mile radius around the Lacey Township plant. Oyster Creek went online Dec. 1, 1969, the same day as the Nine Mile Point Nuclear Generating Station near Oswego, N.Y. But Oyster Creek's original license was granted first, making it the oldest of the nation's 104 commercial nuclear reactors that are still operating.