Another submission listed https://www.saveecobot.com/en/radiation-maps#11/51.3463/30.1... and there you can click on the map markers for recent history. But that website has no help page and I can't read/understand the sources linked.
Also, they claim to have "1 million users", and yet only have 22 Twitter followers: https://twitter.com/SaveEcoBot
It smells of a misinformation campaign to me.