‘lost energy’, is misleading.
a typical nuclear power station puts
60 percent of the reactors-heat-output
into the air/water.
unavoidable.
so what
This is where some kind of nuclear cogeneration would be helpful. That was going to be the case with the Midland nuclear plant, with some of the “waste heat” going to produce process steam for a paper mill (or some other industrial facility). But the anti-nukes killed that one.