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U.S. Nuclear Power: The Vanishing Low-Carbon Wedge

Could nuclear power make a significant contribution to decarbonizing the U.S. energy system over the next three or four decades? The answer: probably not and that’s cause for major concern for anyone who cares about climate change, according to a recently published paper in the Proceedings of the National Academy of Science (PNAS).

Authored by researchers from Carnegie Mellon University’s Department of Engineering and Public Policy (EPP) and Ahmed Abdulla, fellow at the University of California San Diego School of Global Policy and Strategy, the “U.S. nuclear power: The vanishing low-carbon wedge,” paper examined the current U.S. nuclear fleet, which is made up of large light water nuclear reactors (LWRs). While for three decades, approximately 20 percent of U.S. power generation has come from these LWRs, these plants are ageing, and the cost of maintaining and updating them along with competition from low cost natural gas, makes them less and less competitive in today’s power markets. 

In place of these LWRs, the team asked whether advanced reactor designs might play a significant role in U.S. energy markets in the next few decades. They concluded that they probably would not. Then, the team examined the viability of developing and deploying a fleet of factory manufactured smaller light water reactors, known as small modular reactors (SMRs). The team examined several ways in which a large enough market might be developed to support such an SMR industry, including using them to back up wind and solar and desalinate water, produce heat for industrial processes, or serve military bases. Again, given the current market and policy environments, they concluded that the prospects for this occurrence do not look good.

In the article’s conclusion, the team writes, “It should be a source of profound concern for all who care about climate change that, for entirely predictable and resolvable reasons, the United States appears set to virtually lose nuclear power, and thus a wedge of reliable and low-carbon energy, over the next few decades.” 

Lead author on the paper was M Granger Morgan, Hamerschlag University Professor of Engineering at Carnegie Mellon. He was joined by Ahmed Abdulla, Adjunct Assistant Professor in EPP and Research Scientist at the University of California San Diego School of Global Policy and Strategy; along with recent EPP Ph.D. graduate Michael J. Ford (U.S. Navy Retired), now a Postdoctoral Researcher at Harvard; and current EPP Ph.D. student Michael Rath.

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