Firstly, Chernobyl's death-count has to include all the deaths from penumonia and **** that resulted from the radiation destroying people's immune systems.
Secondly, it's got nothing to do with 'killing radiation-vulnerable cells'. Animals whose genetics were normal all got cancer and ****ing died. It's completely different. It's implying low-level exposure increased the resistance in those animals, when

all it did was kill everything else off and leave only those with a natural, pre-existing resistance without any competition.
It operates across the species, not the individual animal.
This will never be of any real benefit to humans as it only acts to restore balance in a radiation-saturated environment, and as soon as the radiation is gone the genes will begin to weaken as non-resistant gene mutations occur and aren't wiped out by the radiation.