"The moment the recorded radiations are too high is already too late, especially if you have kids, that's why we need to know about this type of things before t

"The moment the recorded radiations are too high is already too late, especially if you have kids, that's why we need to know about this type of things before the instrumental devices might show us that the radiation levels have crept up." This is incorrect. Radiation can be managed even after a nuclear strike and largely depends on proximity and subsequent weather patterns. The half-life is short enough that sheltering indoors (preferably in a basement with taped windows) suffices for most scenarios.