I think Palo Verde in AZ should build a forth but i don't think it will happen.
APS has never made a submission to build another one there. Duke may or may not commit to building a new one in Lee Co, SC. Comanche Peak 3/4 are on slo-mo. My contacts there still say it will get built. Crystal River has put their two new units in hibernation, They have bigger fish to fry with the cracked containment buiding on Unit 1 there. There are still rumors that Turkey Point might still commit, but I can’t see that happening until Florida’s economy heats back up.