Rumours are Russia has mined the Zaporizhzhia nuclear power plant. I don't know if it's actually true or not, but I wouldn't put it past them.
1: If there is any possibility to this, I think NATO should make a declaration that if a single isotope reached NATO clay, it's article 5 time which means
A: No NATO troops cross the border into pre 2014 Russia as long as they don't do the same
B: Anything Russian Navy in international waters gets sunk. Russian subs are noisy as fuck and the 'Mericans keep a close eye on things. I am givin to understand that they are all being shadowed and could be sunk before you say Bob's your uncle.
C: Troops on the border with Belurus
D: Ukraine can haz all we can give ASAP
E: NATO anti air assets with NATO experiences crew on Ukraine clay
F: Missiles take out every air base and supply hub within range.
G: More pressure not to deal with Russia on Third parties
H:If Needed NATO troops on Ukraine clay pre 2014 borders
G: No vote in Donuts, Loserchance or Crymea, it goes back to Ukraine because fuck you, that's why
Easy way to avoid that. Don't set off a SECOND FUCKING Chernobyl. If this is true and this does happen and anyone defends this... for fucks sake.
And if not a single Isotope reached NATO clay, wouldn't have a problem with the US and the more robust allies do the above anyway.
2: If there is any hard core evidence that this is the case, I would have no issues with sending in some SEAL/Delta Force/SAS style love to take over. If it can be done safely which it probably can't.