[MichaelCollins]

> If putin keeps the radiation from spilling into nato territory

That is virtually impossible. You can count on at least some detectable level of radioactive fallout reaching a NATO country. That could be enough to trigger Article 5 IF the political leaders of NATO willed it.

To really simulate this sort of scenario properly, you need political wargaming (e.g. matrix games.) And the best way to do that is with politicians themselves, or at the very least members of their staff, participating in the wargames. This isn't the sort of thing you can simulate properly with computers or college students.