The collapse of a plan to build a nuclear power plant with small modular reactors raises concerns about the feasibility of advanced reactors. The project, backed by the U.S. Department of Energy, faced rising costs and lack of buyers. NuScale’s conventional design was the closest to construction. Small reactors offer simplicity and cost reduction, but larger reactors are more fuel efficient. NuScale’s design, using water and low-enriched uranium, won approval from the Nuclear Regulatory Commission. However, the cost of the project continued to rise, making the power significantly more expensive than wind or solar.