ⓘ This report and its underlying modeling were completed in 2022. The scenarios reflect the analytical assumptions and policy landscape at that time and should be interpreted in that context.
This interactive map visualizes results from the Advancing Nuclear Energy report (2022) by The Breakthrough Institute, which uses high-resolution nationwide modeling to evaluate how advanced nuclear reactors could play a major role in a least-cost plan to transition the US power grid entirely to clean energy by 2050.
The modeling was performed using the WIS:dom-P (Weather-Informed energy Systems: for design, operations and markets) optimization model developed by Vibrant Clean Energy (VCE). The model designs a future net-zero CO₂ power sector that meets electricity demand at minimal cost, deploying generation capacity across the continental US at county-level resolution.
Each circle on the map represents a power plant location. Circle size corresponds to installed capacity (MW), and color indicates the dominant generation technology. Use the year slider to see how the power grid evolves from 2020 to 2050, and switch between scenarios to compare outcomes under different assumptions.
Conversion sites (shown as teal diamond markers) represent existing fossil fuel plant sites that the model converts to advanced nuclear reactors. This conversion reuses existing transmission, cooling, and balance-of-plant infrastructure, supporting cost savings and a just transition for local communities. The model deploys advanced reactors at 146 to 254 existing plant sites nationwide across scenarios.
Hover over any state to see a summary of advanced nuclear reactor counts, capital investment, and jobs. Double-click any state on the map to jump to the Dashboard with that state's full profile, including combined advanced nuclear statistics on reactors, jobs, revenue, and ROI.
The study uses a bounding analysis with four scenarios that vary two key uncertainties about advanced nuclear technology:
Across all four scenarios, the model independently chooses to deploy large amounts of advanced nuclear, indicating these technologies provide high value to the electricity system even under conservative assumptions.
Next-generation light-water fission reactors with a template capacity of ~150 MWe per unit. SMRs are designed for factory manufacturing and modular deployment, reducing construction time and enabling flexible siting. Their smaller size facilitates passive safety cooling and standardized production in a "hub and spoke" model.
Advanced reactors that use gas (typically helium) as a coolant and can produce very high outlet temperatures (~80 MWe per unit). HTGRs can supply high-quality industrial heat for applications like hydrogen production, petrochemical manufacturing, and desalination, making them uniquely versatile beyond electricity generation.
Reactors with characteristics similar to liquid-metal or molten-salt fast reactors, coupled with integrated thermal energy storage (~345 MWe base capacity, can ramp to 500 MWe for ~5.6 hours). ARTES can store energy as heat and dispatch it later, enabling effective load-following to balance variable wind and solar generation while maintaining very high reactor capacity factors.
The Dashboard tab provides two sections:
Two optional overlays provide policy and market context for each state:
Policy Climate indicates whether a state has active legislation restricting new nuclear construction:
Electricity Market Structure indicates how power generators recover their costs:
The map displays the top 2,000 largest power plant sites per year (from 8,000–35,000 total grid points in the model). Each data point represents installed generation capacity at a geographic location, with technology breakdowns available by clicking on any circle. Coal conversion sites include the original plant name, capacity, and conversion year.
State-level data (reactor counts, capital investment, jobs, revenue, and ROI) are drawn from the WIS:dom-P full model run spreadsheets and supplementary financial CSVs. The dispatch profile shows one week of hourly generation in a simulated 2050 summer.
The underlying WIS:dom-P model optimizes at 3km spatial resolution with 5-minute temporal resolution, incorporating weather data, transmission constraints, land use, and county-level demand projections.
Post-publication adjustments to conventional nuclear fleet: Several plants have been corrected or added on top of the original 2022 report data to better reflect operating reality. Palisades (Michigan), Three Mile Island Unit 1 / Crane Clean Energy Center (Pennsylvania), and Duane Arnold (Iowa) were shut down after the model was finalized and are shown as restarting; they are not reflected in the scenario projections. Three plants were retired early or omitted by the WIS:dom-P economic optimization and have been reinstated: Ginna (New York, fully merchant since 2017, absent from model), Limerick (Pennsylvania, model retired early 2025; license runs to ~2049), and Davis-Besse (Ohio, model retired early 2025; license runs to 2037). Restart status for all plants follows NRC reactor status records and publicly announced restart timelines.
Citation: Stein, A., Messinger, J., Wang, S., Lloyd, J., McBride, J., Franovich, R. (2022). Advancing Nuclear Energy: Evaluating Deployment, Investment, and Impact in America's Clean Energy Future. The Breakthrough Institute.
Modeling by Vibrant Clean Energy (VCE) using WIS:dom-P.
Regulatory climate data: National Conference of State Legislatures (NCSL).
Electricity market structure: Electric Choice.
Nuclear uprate data: FAI State Permitting Playbook (Nov 2025); INL/EXT-24-78810 (June 2024); NRC approved uprate applications.
Nuclear Share of Total Energy chart — capacity factor assumptions: The WIS:dom-P model reports installed capacity (MW) rather than annual generation (GWh). Energy shares are estimated as capacity × capacity factor × 8,760 hr/yr. Assumed capacity factors: Nuclear / SMR / ARTES / HTGR 90%; Natural Gas CC 50%; CCS 50%; Coal 40%; Hydro 40%; Geo/Bio 80%; Offshore Wind 45%; Onshore Wind 35%; Utility-Scale Solar 22%; Rooftop Solar 15%; Storage 0% (storage is excluded as it does not represent net generation).