Sinister cargo

Waiting for the train down to Englandshire this morning and I saw this train trundeling past. Doesn't take a genius to work out what's in the concrete box on the back given the proximity to Torness Power Station.

I'm just surprised that hey transport this stuff at what would be considered peak travel times.

Just me but I would have thought that there would be less chance of an accident or something through the night when there's less trains on the line?