it downplays the negative impacts of dams. dams prevent sediment from flowing to the ocean which leads to sand loss and erosion
One affects the entire environment with air pollution, and the other affects a localized area by modifying terrain.
I say might, because there is no way of knowing how many deaths will occur (or even statistically should be expected to occur) simply because we don't know what will happen to the nuclear waste.
I favor nuclear, but I'd love to see hard numbers on the 'headroom' nuclear has on deaths/GWH compared to dams, with some argument about whether long-term nuclear waste storage is likely to be less deadly than that headroom.