The reactor would have been critical at 23 inches ( 58.4 cm ) .
It took approximately 100 ms for the rod to travel the final 3.25 inches ( 8.3 cm ) .
The reactor would have been critical at 23 inches ( 58.4 cm ) , and it took approximately 100 ms for the rod to travel the final 3.25 inches ( 8.3 cm ) .