Immediate silent death is grossly over exaggerating. Even in Chernobyl which was absolute worst case scenario that can’t happen with modern designs, the “immediate death” area was directly around the plant.

The concern is cancer in 30 years, not immediate death. Not that trying to downplay cancer, but it really only makes it uninhabitable for humans who live much longer than 30 years. A lot of wildlife basically doesn’t notice since their lives are shorter. It doesn’t mean we should be cavalier about irradiating the environment, but there is no need to go around calling it immediate death.