Construction costs are only part of the picture and utility operators are well aware that they need to look at lifecycle costs. This includes everything from costs of fuel rods (look at the historically volatile uranium market), availability of large volumes of cooling water (see more frequent droughts), maintenance costs (maintenance being a major factor in the retirement of California's nuclear power plants), security costs, the cost of storing fuel rods onsite for decades, and finally, decommissioning costs (as reactors themselves become contaminated with in-situ activation products, i.e. radioactive cobalt/iron/carbon/nickel isotopes).

It's basically a huge long-term liability that just doesn't exist with solar/wind/storage, hydropower, or geothermal.