A 1975 Washington Post article reveals that the then North Anna owners, and ultimately, the NRC, knew that the reactors were built on known fault lines, but construction on two reactors was completed anyway.
Some excerpts from the article headlined: Vepco Fined $60,000 for A-Plant Fault, By Hal Willard. Washington Post, September 12, 1975 -The strongest penalties ever imposed on the nuclear power industry were levied yesterday against the Virginia Electric and Power Company for violations in connection with construction of its four-reactor plant over a geologic fault in Louisa County . . .
The Atomic Safety and Licensing Board fined Vepco $60,000, the maximum allowed by law, and set up stringent conditions that the company must meet to maintain a nuclear license for its North Anna plant...
Vepco was convicted of making 12 “material false statements” to the NRC in reference to the geologic fault. In essence, they were that Vepco said there were no faults at the North Anna site and none were suspected. All parties, including Vepco, now agree the fault exists . . .
The geological conditions at the North Anna site were investigated by Vepco consultants in 1968 and 1969. They said they found no fault. An outside geologist found the fault in 1970 and Vepco’s consultants confirmed the fault in May, 1973.