I shone it toward Alice’s face. Her pupils dilated in the sudden light.... Now, unless the three-year-old Alice was a neurosyphilitic manifesting Argyll Robertson pupils, her pupils should have done exactly the opposite. They should have contracted in the sudden light.
This is not such a clear-cut case, but it suggests that the author thinks Chernobyl was a nuclear explosion, like Hiroshima or Nagasaki. Burnt-out buildings, blackened tree stumps, charred teddy bears — all point to that interpretation. I also don’t know whether there were any grainy documentaries of Chernobyl that might have plausibly made it to the West for the character to have watched them.