I kind of doubt this story. What kind of radiation would you have from Chernobyl?

My understanding is that bit flips (SEEs) are typically caused by energetic particles like cosmic rays. To simulate upset damage on Earth, you typically need to decap the IC and go to a testing facility that directly hits the wafer with particles. It seems unlikely that somewhere near Chernobyl that there would be particles energetic enough that didn't get stopped by the IC packaging.

Gamma radiation gives total ionizing dose effects that degrade chips until the point they no longer work. Those shoot right through the chip packaging. But I don't think it typically causes upsets.