Any information coming out of the Soviet Union - real state-controlled media - is suspect. The Soviets routinely encouraged reports of UFOs, etc., to cover up missile testing and other military activity.
These skiers probably ran afoul of some military operation (if the radiation angle is true) or fell victim to the natural dangers of being out in the wild in the winter.
I say this as someone who has been interested in Forteana for most of my life: Most “reporting” before WWII is suspect, especially old small-town newspapers with blank pages to fill. As much as we say journalists make stuff up now, back then they really did.
I love Fortean Times, I’ve been a subscriber since about Issue #32.
I am on board with everything you wrote.