The Definition and Characteristics of SMRs
Small modular reactors (SMRs) are nuclear reactors that can generate up to 300 megawatts of electricity per unit. Unlike traditional large-scale nuclear reactors, SMRs are designed to be modular, flexible, and deployable, making them an attractive option for energy production. The International Atomic Energy Agency (IAEA) defines SMRs as nuclear reactors that can generate electricity at a scale of 1-300 megawatts.
Advantages of SMRs
The advantages of SMRs include:
- Modularity and flexibility of deployment
- Lower costs and reduced environmental impact
- Improved safety features and reduced risk of accidents
- Potential to provide baseload power and reduce greenhouse gas emissions
Economic and Environmental Viability
In 2018, the U.S. Department of Energy allocated $900 million to fund domestic SMRs as part of their commitment to clean energy. The U.S. Secretary of Energy, Jennifer M. Granholm, emphasized that this investment “advances environmental protection and community benefits, creates new, good-paying, high-quality jobs, and reinforces America’s leadership in the nuclear industry”.
Figure 1: Economically Viable Deployment of SMRs
Figure 1 shows the economically viable deployment of SMRs at industrial facility processes in SPP (left) and ERCOT (right) when providing process heat only across avoided natural gas costs.
Recent Designs and Their Modularity and Safety
NuScale Power Corporation, an American SMR marketing company based in Oregon, is the first company to have their SMR design approved by the U.S. Nuclear Regulatory Commission (NRC) in 2022. Their NuScale US600 SMR prioritizes in-house production and modular designs, powering planes with up to twelve reactors that output 50 MWe each.
Figure 2: NuScale US600 SMR Diagram
Figure 2 shows the NuScale US600 SMR diagram, U.S. NRC, 2022.
Hybrid Systems
SMRs are often considered as modular parts in systems with renewable energy grids. The versatility of thermal energy SMRs produce can address shortfalls where wind and solar resources are unpredictable. In 2023, Masotti et al. studied the simulation of iPWR SMRs in hybrid energy systems.
Figure 7: Energy Grid Diagram
Figure 7 shows the energy grid diagram, including SMRs as an additional power source to produce hydrogen when electrical energy is insufficient.
Conclusion
SMRs represent a significant step towards the pursuit of clean and sustainable energy. Their modularity, advanced safety systems, and innovative fuel sources make them a compelling and versatile tool in modern energy grids. However, many of these technologies face challenges such as high initial costs, regulatory hurdles, and fuel optimization, which remain significant roadblocks.
About the Authors
Dr. Raj Shah is a Director at Koehler Instrument Company in New York, where he has worked for over 25 years. He is an elected Fellow by his peers at IChemE, ASTM, AOCS, CMI, STLE, AIC, NLGI, INSTMC, Institute of Physics, The Energy Institute, and The Royal Society of Chemistry. Mr. Bradford Leung is part of a thriving internship program at Koehler Instrument company in Holtsville, and is a student of Chemical Engineering at Stony Brook University, Long Island, NY, where Dr. Shah is the chair of the external advisory board of directors.
Works Cited
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