Vogtle 3 and 4 didn't turn out seven years late because of regulation, other than an insistence that they be built to spec. All permits were issued in a timely fashion. The reactors were late because of construction screw-ups. The reinforcing rod structure was built badly out of spec; most of a year was lost to an engineering study to find a work-around. When the concrete floor was poured, it was supposed to be level; there was an almost six inch slope. Again, large amounts of time lost to engineering a work-around. Welds on the large forgings were improperly done in the factory and had to be redone in the field (including moving in the necessary x-ray inspection gear). Special-alloy piping that couldn't be exposed to outside weather sat outside for 18 months while no one noticed, so things sat still while replacements were obtained. A year was lost when cost overruns put Westinghouse in bankruptcy and the courts had to sort out who was paid, how, and the organization under which the project would move forward.
The UAMPS small modular reactor project was permitted in record time. It was canceled after some years because the projected cost of the electricity kept increasing, and reached the point where it was too expensive for the utilities who were to be the customers to justify.