The U.S. has an increase in energy demand, and if we consider phasing out fossil fuels then the demand for new power plants is huge.

Arkansas nuclear one which started construction in 1968 and finished in 1974 had a total construction cost of 2.522B (2007 dollars) and produces 13555 GWh a year with a 66 year license giving it a $2.81//MWh in general initial construction represents 60-80% of total nuclear power costs so if we use the conservative value that’s still under $5/MWh using 2007 dollars and if we scale to today that’s $8/MWh. So not sure what you mean by it didn’t drop costs.

It was expensive compared to fossil fuels that had little to no safety systems