[coryrc]

Manhattan is an island. It's surrounded by cooling fluid.

> Sometimes people don't want heating, but you still need to cool down the plant.

You can turn it down or off.

> Remind me why power lines aren't an option?

It's more economical not to waste half the plant's power output. 1 GW of heat comes out the reactor, 50% becomes electricity (with heat pumps you can make that 2x heating) and 50% is low-grade heat sufficient for space heating. You get 1/3 more heating for the same cost.