Nuclear isn't out only option. Solar and wind are economically much more viable, and are safer (as in: they don't produce population displacing disasters, even if they might kill more people on average). Grid scale storage is becoming cheaper as well.
Of course the belief that nuclear will be replaced by solar and wind is a bit naive: in the short term it's replaced by coal and gas, and only in the medium term can we hope for better
An exclusive solar and wind power grid is not more economical viable than an exclusive nuclear power grid, as is daily proven be the absent of such grids being developed. A power grid that combines solar, wind and fossil fuels are more economical viable than a power grid made by nuclear plants, and thus this combination is today out competing nuclear by a wide margin. Grid scale storage technology may in the future make solar, wind and storage a more economical viable solution than nuclear but no such power grid exist to date.
The economic viability of any energy source is depending on how the composition of the energy grid. Economic comparison between two sources is generally meaningless without the context of the grid, especially supply and demand.
Of course the belief that nuclear will be replaced by solar and wind is a bit naive: in the short term it's replaced by coal and gas, and only in the medium term can we hope for better