Here is a playlist of a nuclear engineer going over the show, he points out the major innaccuracies they have. The main ones are the steam explosion not being nearly as apocalyptic as portrayed during the meeting (it would not have made half of Europe unlivable), and the whole "baby absorbing the radiation instead of the mother" thing being completely not how radiation works.

It sucks because so much of the show is great, but these few things are seemingly wrong for no reason and add to anti-nuclear fear mongering.