Nuclear weapons detonations gives completely another curve in radiation level change.

Radiation level does not rise day before nuclear detonation, and fall at the moment of detonation, it rises seriously at exact moment of detonation and then decline, fast initially, when short-living isotopes decay, slowly later, leaving some noticeably rised background.

Pavlograd and Ternopol sensors show nothing suspicious at all, only Khmelnitsky sensor data looks suspicious. You could check that by yourself.