In a May 2011 New York Times report, NRC Chairman Gregory B. Jaczko said the shield building's design numbers seemed off. Jaczko, who stepped down as chairman in July, said the company had not tested the buildings under enough possible seismic activity situations.
However, the five-member NRC voted in favor of the licenses four to one, with Jaczko being the lone vote against it. Jaczko said he wouldn't speak on record to CNN, but he told CNNMoney on February 9 that the new licenses don't go far enough in requiring the builders to incorporate lessons learned from Fukushima.
Hannah explained there were many versions of the AP1000 design that raised questions among critics during its creation. The shield building was a major area of concern but was fixed before the final design was approved, he said.
A total of 19 changes have been submitted since the design began in 2002, the last of which came in June 2011, according to the NRC website.
Asked about Lyman's assertion that the Vogtle plants would incur problems if they went 10 days without power, as did the reactors at Fukushima, Hannah said all plants have some sort of backup generator that allows power to be generated in an emergency -- even one as big Fukushima.
"We have a task force specifically designed to find out what kind of backup generators will work best in these situations," he said.
Along with the safety concerns, critics have other questions about the reactors.
For one: Why build new reactors when there are cheaper energy sources, namely natural gas?
Lyman is one of those critics, and he points to the $14 billion price tag for the two reactors, which some estimates indicate may be $1 billion short of the actual cost.
"The enormous price tag of new nuclear power projects, such as Vogtle 3 and 4, means that nuclear power is not cost-effective, especially given the low price of natural gas," Lyman said.
According to the Energy Information Administration website, new low-cost drilling technologies, growing production and an increase in reserves have made natural gas a primary source for energy, rivaling coal for the first time in April.
Before the U.S. approved plans for 13 nuclear reactors this year, the last nuclear reactor was built in 1990.
Collins downplayed the natural gas argument during the France-Atlanta conference.
While it is "the right choice of energy in terms of cost" right now, she said it has been volatile lately and that using nuclear energy is a better option as a long-lasting energy source.
The EIA states that prices for 1,000 cubic feet of natural gas, a standard measure, have fluctuated greatly of late, from $9.84 in December 2011 to $15.94 in August.
Plant Vogtle has had two nuclear reactors in operation since 1989. Unit 3 is scheduled to be in operation by 2016, and Unit 4 is scheduled to be operational a year later.
Vogtle's were the first reactors to be approved since 1978, the year before America witnessed its most serious nuclear plant meltdown.
On March 28, 1979, a unit at the Three Mile Island nuclear power plant experienced a combination of equipment malfunctions, design-related problems and worker errors that led to a partial meltdown of the unit's reactor core. It took nearly 15 years to clean up the damage.
Though no deaths or injuries occurred to plant workers or people in the nearby community of Middletown, Pennsylvania, the Three Mile accident brought about numerous safety changes in the nuclear plant industry that still resonate today.
Likewise, other countries haven't taken the events at Fukushima lightly either, and much like Three Mile Island gave the world pause in its nuclear ambitions, Fukushima is prompting changes around the globe.