Small modular nuclear reactors (SMRs) could play a key role in Washington State’s mandated transition to a clean energy economy, according to a new report by researchers at the Pacific Northwest National Laboratory (PNNL) and the Massachusetts Institute of Technology.
Washington’s Clean Energy Transformation Act, enacted in 2019, calls for the elimination of coal-fired generation by 2025, aims to reach carbon dioxide (CO2) neutrality by 2030, and requires that the state’s power sources must generate electricity without emitting greenhouse gases by 2045.
The phasing out of coal- and natural gas-fired generation, which supplied about 17 percent of the state’s fuel mix in 2018, will leave a roughly 5-gigawatt (GW) gap in generation capacity that SMRs could help fill, according to the report, “Techno-economic Assessment for Generation III+ Small Modular Reactor Deployments in the Pacific Northwest.”
The report analyzed five case studies combining two SMR technologies and three potential sites. The study evaluated deployment of NuScale-designed plants, each containing 12 SMR units delivering roughly 600 megawatts (MW) to 700 MW at three different sites, and deployment of GE-Hitachi (GEH)-designed SMR plants delivering roughly 300 MW at two different sites.
The first case analyzed deployment of NuScale SMRs at the Idaho National Laboratory in Idaho Falls, Idaho, as a potential site for the Utah Association of Municipal Power Systems’ (UAMPS) Carbon Free Power Project. In January, UAMPS and NuScale signed an agreement to facilitate the development of a nuclear plant at the site.
In May, the Grant County Public Utility District signed a memorandum of understanding with NuScale to evaluate the deployment of the company’s SMR technology in central Washington.
The second case looked at using NuScale SMRs at a site near Energy Northwest’s Columbia nuclear plant in eastern Washington.
The third case studied placing a GE-Hitachi SMR at the Idaho National Laboratory site using the same cost reductions as the NuScale plant. The fourth and fifth cases evaluated using NuScale and GE-Hitachi designs, respectively, at the Big Hanaford coal-fired plant in Centralia in western Washington that is scheduled to close its coal-fired units in 2025.
The analysis indicated that in a future CO2 free electricity sector deployment of advanced SMRs would be competitive with Levelized Costs of Electricity (LCOEs) in the range of $51 per megawatt hour (MWh) to $54/MWh for the NuScale design and in a range of $44–$51/MWh for the GE-Hitachi design.
Each of the three sites also provides additional advantages, according to the report. There is already existing infrastructure and a workforce trained in the operation of conventional and nuclear plants in place in eastern Washington, and the Centralia site has existing grid connections that could be tapped, as well as a workforce that could be shifted from the closing coal-fired units.
The authors noted that they used two different means of calculating LCOE. For NuScale, they used the company’s current design. For GE-Hitachi, they used that company’s design-to-cost methodology with target pricing that is being confirmed as the design matures.
The findings “show that advanced small modular reactors could be economically competitive in a future carbon-free electricity sector,” Ali Zbib, PNNL’s manager for nuclear power systems and a co-author of the report, said in a statement. “They’re well-suited to play an important role in an energy market that requires more flexibility.”
The report noted that advanced SMRs can operate continuously at full power to provide baseload energy or can follow power swings on the grid. The report also found that electricity demand in Washington can fluctuate significantly on a monthly, daily and even five-minute basis, noting that average daily demand in February 2019 varied by more than 2,100 MW.
The report also noted, however, that near-firm renewable resources, such as wind power coupled with energy storage, “may provide competition to SMR generation.” The report cited a 1-MW, 150-MWh storage system developed by Form Energy in Minnesota that will provide Great River Energy with dispatchable wind power.
And, given the relatively short development time for such projects “and their relatively inexpensive power, they may provide stiff competition to the longer permitting to generation time paths for SMRs.”
At current prices, the cost of long-term storage “is prohibitively high to keep the lights on using only variable renewable energy,” the report found.
Lithium ion batteries cost approximately $200 per kilowatt hour (kWh) for approximately 4 hours of storage, the authors noted. They cited a MIT study indicating that storage costs could need to be as low as $20/kWh for long-term storage to be feasible.
Nonetheless, renewable energy still suffers from its variability and, even with its comparably low cost compared with firm power alternatives, “it fails to provide the flexibility required to meet long duration periods when wind and sun are not providing adequate electricity,” the report said.
While wind and solar will play a critical role, phasing out carbon-emitting resources sparks the need for flexible, non-carbon-emitting sources, and “nuclear energy can be an integral part of a clean energy portfolio that will allow the state of Washington to meet its clean energy objectives,” Zbib said.
The report is available here.