There are times when it takes longer, such as when Fukushima had a meltdown. The thirty-second answer only starts to explain how it happened, the thirty-minute one makes you start to realize that a good part of it is because people fucked up, and the full answer, which requires going over reports since the construction of the plant shows you just how comprehensive the fuck-ups were and why it was only a matter of time for something that catastrophic to happen.
But yes, usually these things can be figured out pretty quickly. It doesn’t take nuclear science to figure out why they can’t do their job.