As an Ohio uranium enrichment plant opened this month, yet another study questioned whether nuclear power from small modular reactors can compete with other types of electricity generation.Â
Centrus Energy’s new plant in Piketon produces high-assay, low-enriched uranium, or HALEU. The fuel will contain between 5% and 20% fissile uranium, or U-235, which is the range needed for various types of small modular reactors, or SMRs. The current fleet of large nuclear reactors uses fuel with up to 5% U-235.
Large nuclear plants have had problems competing with other types of electricity generation in recent years. Ohio’s House Bill 6 would have mandated ratepayer spending of more than $1 billion to subsidize the 894-megawatt Davis-Besse plant and 3,758-megawatt Perry plant in Ohio, for example. Lawmakers repealed that law’s nuclear subsidies after alleged corruption came to light.
Now the question is whether small modular reactors designed to produce up to 300 MW of electricity can compete better.
Huge gigawatt-scale nuclear plants can have economies of scale because their power output grows faster than increases in capital and operating expenditures.
“However, the extensive customization of many of the currently deployed reactors undercuts much of that economy,” said William Madia, a nuclear chemist and emeritus professor at Stanford University who is now a member of Centrus’ board of directors.
The lack of a standard design also makes it harder for large reactors to get replacement parts when needed. “Things like large-scale forgings are in short supply globally,” Madia noted.
In contrast, small modular reactors can be built in indoor factories and then sent to where they’ll be used. That avoids site-by-site mobilization costs, as well as weather problems that might interrupt construction.Â
“But the real driver is standardized design,” Madia said. So eventually, production can take place on assembly lines. And that should produce its own economies.
All in all, “the capital cost for SMRs is much lower than GW-scale machines,” Madia said. Also, if the choice is between lower-cost modular reactors and huge ones, “many, many more utilities can afford a few billion dollars on their balance sheets. Very few can handle $10-plus billion.”
Facing competition
No small modular reactors are operating commercially in the United States yet. Â