I don't think there's much of a practical difference. With the exception of withholding public knowledge, as in the case of Chernobyl. If anything nuclear warn

I don't think there's much of a practical difference. With the exception of withholding public knowledge, as in the case of Chernobyl. If anything nuclear warning systems (in the us, at least) are extensive within the ~30 mile zone (sirens everywhere), and have published plans for a ~60 mile zone, while I've never heard of warning systems for dams. Which isn't too say they're not-existant. Also, dam failures tend to happen during bad weather where evacuation is greatly hindered. This was an issue with the Oroville dam partial failure in 2017. Whereas in Fukushima, the warning and evacuation was effective even in the midst of the tsunami aftermath.