Its not cost effective. The US's latest nuclear plant took 15 years to build and cost $35 billion. The 15 years part alone is enough reason to focus on other energy sources
https://www.construction-physics.com/p/why-are-nuclear-power...
The latter is largely due to the anti nuclear movement, as sponsored by the petroleum industry. This will go down in history as one of the biggest self-owns in trying to protect the environment.
https://www.forbes.com/sites/kensilverstein/2016/07/13/are-f...