How small modular reactors could expand nuclear power in the U.S.

Nuclear plants could become smaller, simpler and easier to build in the future, potentially revolutionizing a power source that is increasingly viewed as critical to the transition away from fossil fuels.

New designs called small modular reactors, or SMR in shorthand, promise to speed deployment of new plants as demand for clean electricity is rising from artificial intelligence, manufacturing and electric vehicles.

At the same time, utilities across the country are retiring coal plants as part of the energy transition, raising worries about a looming electricity supply gap. Nuclear power is viewed as a potential solution because it is the most reliable power source available and does not emit carbon dioxide.

Building large plants is very costly and time-consuming. In Georgia, Southern Co. built the first new nuclear reactors in decades, but the project finished seven years behind schedule at a cost of more than $30 billion.

Small modular reactors, with a power capacity of 300 megawatts or less, are about a third the size of the average reactors in the current U.S. fleet. The goal is to build them in a process similar to an assembly line, with plants rolling out of factories in just a handful of pieces that are then put together at the site.

“They’re a smaller bite from a capital perspective,” Doug True, chief nuclear officer at the Nuclear Energy Institute, told CNBC. “They’re a perfect fit for things like replacing a retired coal plant, because the size of coal plants typically is more than that of the small modular reactor design space.”

The challenge is getting the first small modular reactor built in the U.S.

Only three SMRs are operational in the world, according to the Nuclear Energy Agency. Two are in China and Russia, the central geopolitical adversaries of the U.S. A test reactor is also operational in Japan.

Executives in the nuclear industry generally agree that small modular reactors won’t reach a commercial stage until the 2030s. An ambitious effort by NuScale to deploy SMRs at a site in Idaho was canceled last year, as the project’s price tag ballooned from $5 billion to $9 billion due to inflation and high interest rates.

Eric Carr, president of nuclear operations at Dominion Energy, said the biggest challenge to commercializing the technology right now is managing the costs of a first-of-a-kind project.

“Nobody exactly wants to be first, but somebody has to be,” Carr told CNBC. “Once it gets going, it’s going to be a great, reliable source of energy for the entire nation’s grid.”

Dominion is currently evaluating whether it makes sense to build a small modular reactor at its North Anna nuclear station in Louisa County, Virginia, northwest of Richmond. The utility’s service area includes the largest data center market in the world in Loudoun County, less than 100 miles north of the plant.

Electricity demand from these computer server warehouses is expected to surge because artificial intelligence consumes more energy. In…