The lifetime cost of of nuclear (build, running + clean-up) divided by the amount of electricity created is incredibly high. This report from csiro doesn't include large scale nuclear but does include projected costs for small modular reactors +solar and wind. Generally large reactors come out behind smr especially in future projections.

https://www.csiro.au/en/research/technology-space/energy/energy-data-modelling/gencost

Note the "wind and solar pv combined" "variable with integration costs" which is the cost accounting for storage, transmission etc. It's not that high (at least up to the 90% of the grid modelled for 2030). The best end of the nuclear estimate is double the cost of that. The reasons that the storage costs etc. Are not as high as you may intuitively expect are explained in that report.

Maybe there is a place for nuclear in that last 10%, but not in less than that. Also as far as rolling it out quickly, look at how long this last nuclear plant took to build from planning to construction being complete.

I think that it is possible to manage the cleanup of nuclear and to make it safe, but it's all just very expensive. To make everyone happy with the transition off fossil fuels it needs to be cost competitive and renewables are, nuclear isn't.