A screening tool should be tested against what developers actually do. So we wrote down a rule, applied it before looking at a single score, and report every result, good or bad.
The rule
We included every U.S. commercial nuclear power-reactor project, new plants and restarts of permanently shut-down reactors, for which an application filed with the Nuclear Regulatory Commission since January 1, 2020 was pending or approved as of October 16, 2026: a construction permit, combined license, operating license, early site permit (new or renewed), or the exemption and license amendments needed to restart a shut-down reactor. Each site is the one named in the NRC docket or the applicant's filing. We excluded research and test reactors, isotope production, reactors authorized by the Department of Energy rather than licensed by the NRC, license renewals and uprates, and withdrawn or denied applications. Projects in formal pre-application talks with the NRC for a named site are listed separately.
Excluded, and why: Vogtle Units 3 and 4 (licensed long before the cut-off), Oklo's Aurora application at Idaho National Laboratory (denied in 2022; its successor is authorized by DOE), Kairos Hermes and other research or test reactors, isotope-production facilities, reactors in DOE's pilot program, and older licenses with no new filing.
That gives 12 projects, plus 5 in pre-application. A project matches a Voltane candidate when its site is within 3 miles of one (using coordinates from the NRC filing or the applicant's environmental report), or when the docket names an existing plant as the site. We never placed a site by estimate.
| Project | Site | In Voltane | Micro | SMR | Large |
|---|---|---|---|---|---|
| Kemmerer Power Station Unit 1 | Kemmerer Unit 1 Site, Lincoln County, Wyoming | Not a candidate; nearest: Kennecott Power Plant, 106 mi | not scored | not scored | not scored |
| Long Mott Generating Station | Long Mott (Dow Seadrift site), Calhoun County, Texas | Not a candidate; nearest: South Texas Project, 47 mi | not scored | not scored | not scored |
| Clinch River Nuclear Site, Unit 1 | Clinch River Nuclear Site, Roane County, Tennessee | Candidate: Clinch River Nuclear Site (Early site permit, DOE / federal site) | 76.6 | 69.8 | 64.6 |
| Pioneer Units 1 and 2 (Palisades SMR-300) | Palisades Energy Center, Covert, Michigan | Candidate: Palisades Nuclear Plant (Existing nuclear site) | 80.7 | 82.3 | 74.3 |
| Belews Creek Early Site Permit | Belews Creek site, Stokes County, North Carolina (next to Belews Creek Steam Station) | Not a candidate; nearest: R J Reynolds Tobaccoville Utility Plant, 15 mi | not scored | not scored | not scored |
| Project Matador Nuclear Units 1-4 | Project Matador campus, Carson County, Texas (next to DOE Pantex) | Candidate: Pantex Plant (DOE / federal site) | 72.5 | 72.5 | 62.9 |
| Blue Energy Center-Port of Victoria Nuclear Unit 1 | Blue Energy Center, Victoria, Texas | Location not retrieved from a primary source | not scored | not scored | not scored |
| Palisades Nuclear Plant restart | Palisades Nuclear Plant, Covert Township, Michigan | Candidate: Palisades Nuclear Plant (Existing nuclear site) | 80.7 | 82.3 | 74.3 |
| Crane Clean Energy Center restart (Three Mile Island Unit 1) | Three Mile Island, Dauphin County, Pennsylvania | Candidate: Three Mile Island / Crane Clean Energy Center (Shut-down nuclear site) | 65.8 | 74.5 | 73.3 |
| Duane Arnold Energy Center restart | Duane Arnold Energy Center, Linn County, Iowa | Candidate: Duane Arnold Energy Center (Shut-down nuclear site) | 87.5 | 84.4 | 72.4 |
| Grand Gulf ESP Site (renewal) | Grand Gulf ESP Site, next to Grand Gulf Nuclear Station | Candidate: Grand Gulf Nuclear Station (Existing nuclear site, Early site permit) | 81.0 | 93.3 | 91.4 |
| North Anna ESP Site (renewal) | North Anna ESP Site, Louisa County, Virginia | Candidate: North Anna Power Station (Existing nuclear site, Early site permit) | 80.7 | 85.1 | 81.2 |
| Cascade Advanced Energy Facility | Next to Columbia Generating Station, Hanford, Washington | Candidate: Columbia Generating Station (Existing nuclear site) | 79.9 | 85.3 | 75.8 |
| Joshua Falls Early Site Permit | Joshua Falls property, Campbell County, Virginia | Location not retrieved from a primary source | not scored | not scored | not scored |
| Last Energy Haskell site | Haskell, Texas | Location not retrieved from a primary source | not scored | not scored | not scored |
| RELLIS Campus ESP | Texas A&M RELLIS Campus, Bryan, Texas | Location not retrieved from a primary source | not scored | not scored | not scored |
| Kewaunee New Nuclear Initiative | Kewaunee Power Station site, Kewaunee County, Wisconsin | Candidate: Kewaunee Power Station (Shut-down nuclear site) | 74.5 | 84.2 | 78.4 |
Scores out of 100 at each class's default weights; "not scored" means the site is not a Voltane candidate. Ranks and sources are in the data file. Data (JSON)
Screening only — not a site suitability determination.
The hits
Of the 12 projects, 8 sit on a Voltane candidate site, and 5 of those score in the top quarter of all 504 candidates for SMRs.
- Grand Gulf (early site permit renewal, Mississippi) scores 93.3 for SMRs, rank 3 of 504, and 91.4 for large reactors (rank 8). It loses most on load proximity (data centers).
- North Anna (early site permit renewal, Virginia): 85.1 for SMRs (rank 67). Its weakest criterion is seismic hazard.
- Duane Arnold (restart, Iowa): 84.4 for SMRs (rank 73) and 87.5 for microreactors (rank 20), helped by data centers nearby. It loses most on population exposure.
- Palisades (restart) and Pioneer Units 1 and 2 (Holtec SMR-300, same site, Michigan): 82.3 for SMRs (rank 96). Its weakest criterion is flood hazard: Voltane's flood data does not model Great Lakes shorelines, so the site earns no points there. That is "unknown", not a finding of flood risk.
The middle
- Crane, the Three Mile Island restart (Pennsylvania): 74.5 for SMRs (rank 214) and 65.8 for microreactors (rank 372). It loses on population exposure and distance to a population center: many people live nearby. A restart does not need a new site, so this is a case where screening and a real decision use different questions.
- Clinch River (TVA, BWRX-300, Tennessee): 69.8 for SMRs, rank 300. It loses most on existing interconnection at the site, because no plant ever ran there, and on seismic hazard in East Tennessee. It holds an early site permit and now a construction permit.
- Project Matador (Fermi America, AP1000, Texas) matches the Department of Energy's Pantex site next door and scores 72.5 for SMRs (rank 244). It loses on existing interconnection at the site and major surface water nearby.
The misses
3 projects are not on Voltane's candidate list at all, and one we could not place:
- Kemmerer (TerraPower Natrium, Wyoming), which received its NRC construction permit in March 2026. The site is a few miles from the Naughton coal plant, but EIA-860M lists Naughton's coal units as operating with no planned retirement date, so Voltane never counted it as a coal candidate. The nearest candidate is 106 miles away.
- Long Mott (Dow and X-energy, Xe-100, Texas): a reactor built for industrial heat at a chemical plant. Voltane has no family for industrial hosts. Nearest candidate: 47 miles.
- Belews Creek (Duke Energy early site permit, North Carolina): next to an operating plant that EIA-860M now records as burning natural gas, with no retirement date. Nearest candidate: 15 miles.
- Blue Energy, Port of Victoria (Texas): filed in September 2026; we could not retrieve the site's coordinates from a primary source, so it is unplaced.
What the misses teach
- Operating coal and coal-to-gas plants are invisible until they file a retirement date. Kemmerer and Belews Creek both sit next to such plants. Adding them as candidates is the clearest fix.
- Industrial hosts are a real category. Long Mott is about process heat for a chemical plant, not grid power. Voltane screens for grid power; it should at least list large industrial heat users.
- Greenfield sites score low on interconnection by design. Clinch River earns nothing for generation at the site because none exists. The weight is a product assumption, and this backtest is evidence for revisiting it.
- Missing data shows up. Palisades and Pioneer lose points for flood data that does not exist on the Great Lakes shore, not for a known risk.
In pre-application, 2 of the 5 named sites are Voltane candidates; the others, greenfield or campus sites, have no primary-source coordinates we could retrieve yet.
Screening only — not a site suitability determination.