As posted by Fred Hayek, Westinghouse is a subsidiary of Toshiba. Toshiba is far far underwater after Fukashima melt down. The financial collapse of Toshiba took down any capacity they had to manage and upgrade Westinghouse into a functional business, let alone a profitable one. Westinghouse wasn't anywhere close to budget, causing huge cost overruns, and pulling out of the construction process has required replacing them as prime contractor, which heaps on the overhead and costs. What a mess.
The most efficient way to re-start the US commercial nuclear plant program would be to standardize the designs. If you look at the plants that built multiple reactors of the same design, the first one took the longest because of multiple design conflicts with its systems. The second plant takes about a 25% to 40% less time because they incorporated the needed design changes and if they built a third plant the time savings is approaching 50% or higher. That is what doomed WPPSS. 5 different reactor designs in 3 separate locations. And when they shut down plants 4&5 ( 1&4 we’re twins and 3&5 we’re twins) those two plants were only several months from the same phase of construction as their twins in less than half the time.