Fact 1: Physics says it should be cheaper, because of massive energy density, as you need less stuff, and so less human effort to juice the energy source. Even

Fact 1: Physics says it should be cheaper, because of massive energy density, as you need less stuff, and so less human effort to juice the energy source. Event history: 1. lots of reactors in the 60s and 70s 2. reactors are water cooled and designed essentially like normal power reactors, meaning they are similar size and operate with little margin 3. accidents happen - accidents that were conceivable though beyond the design basis 4. environmental and mass resistance heats up in response to 3 - rightfully so 5. 3. also leads to pressure to make current reactors safer by adding safety systems 6. reactors turn into giant jumble of safety systems with massive man power and maintenance costs, costs that similar sized coal or natural gas do not have. The increase in safety systems enhances safety superficially, and costs increase until the plant is barely break even. The key is that the accidents created a new and higher demand for safety that could not be economically met by the previous designs. But those previous designs were in place and had to operate, so they back-engineered a bunch of crap to make them "safe" at huge cost - a cost that basically annihilates all of nuclear's energy density benefits. At the same time, resistance was too high to build new reactor design concepts that could match the new safety paradigm, and so gen IV was not achieved. What you say is true - "it is not economically viable." But you shouldn't bundle all of nuclear into that category. The crap from the past was not economically viable with safety standards we have today. What's coming is.