Stellan Skarsgaard is amazing. His acting this episode was emmy worthy. The dawning realization of how bad it was, personaly and globally, the use of his authority to get the scientists' words across when it mattered. I loved him in River, too. He tore my heart out, stomped on it, and brought it back to life in the last episode of that. Saw him recently in The Man Who Killed Don Quixote and he was fantastic there too. The man is a chameleon.
The horror of that hospital and the evacuation. I'm old enough to remember this vividly along with three mile island, which wasn't anywhere this bad.