Background: Small modular reactors, explained: who is building them worldwide · Every Nuclear Plant Under Construction in the US in 2026
Current state
| Status | Planned |
| Design | SMR-300 (PWR, SMR) |
| Net capacity | 340 MWe |
| Country | United States |
| Vendor | Holtec International |
| Owner / operator | Holtec International (Palisades SMR, LLC) |
| Construction start | — |
| Original COD target | — |
| Current COD estimate | — |
| Schedule slippage | — |
Notes
Second of two SMR-300 units planned beside the restarting Palisades plant. Capacity is the 340 MWe per unit reported by ANS, consistent with Holtec's 680 MWe for the pair; Holtec's 2025 launch release and WNN describe the SMR-300 as about 300 MWe. Holtec now targets commissioning in the early 2030s (no year given), and the original 2030 target applied to the first unit, so both COD fields are left empty. Early site work is under way under an NRC exemption; nuclear construction awaits a limited work authorization and construction permit. Holtec names Hyundai E&C and Mitsubishi Electric as partners without a published EPC designation. Selected in December 2025 for up to $400 million in DOE cost-shared funding, effective once a funding agreement is executed.
Milestone log
- 2025-02-25 — Holtec launched "Mission 2030" to build two SMR-300s at Palisades, targeting 2030 for first commercial operation (source)
- 2025-12-31 — Holtec subsidiary SMR, LLC filed Part 1 of a phased construction permit application (limited work authorization request and environmental report) for Pioneer Units 1 and 2 (source)
- 2026-02-13 — NRC found Part 1 acceptable for docketing (Docket 50-617 for Pioneer Unit 2) (source)
- 2026-08-28 — NRC granted an exemption allowing installation of permanent support-of-excavation and cutoff-wall systems before a limited work authorization; it does not commit the NRC to an LWA or construction permit (source)
- 2026-09-30 — Holtec submitted the Preliminary Safety Analysis Report, completing the second phase of the construction permit application; NRC draft safety evaluation for the LWA anticipated December 2026 (source)
The milestone log is append-only: corrections are recorded as new entries, never rewrites. Full history via /api/v1/changes.
NNN coverage
At Palisades Nuclear Plant
- The 7 nuclear stories that mattered this week 2026-10-03
- Holtec files Palisades SMR safety report with NRC 2026-10-03
- Fuel assembly incident pauses Palisades loading 2026-09-26
- The 8 nuclear stories that mattered this week 2026-09-05
- NRC finds two Green radiation-safety lapses during Palisades restart 2026-09-05
- Palisades fuel loading: Holtec restart timeline and what comes next 2026-09-01
On the SMR-300 design
- Nuclear power for data centers, explained: every deal tracked 2026-10-01
- Analysts size Africa's SMR market at $105B, 15 GW by 2035 2026-09-07
- Top SMR developers in 2026, ranked by what they've actually built 2026-08-05
- The nuclear decommissioning market in 2026: size, players, pipeline 2026-07-14
- Small modular reactors, explained: who is building them worldwide 2026-07-09
- NRC opens environmental review of Holtec's Palisades new-build 2026-06-17
Sources
- https://www.govinfo.gov/content/pkg/FR-2026-02-27/html/2026-03943.htm
- https://www.ans.org/news/2026-01-14/article-7673/holtec-submits-partial-construction-permit-application-for-smrs-at-palisades/
- https://holtecinternational.com/hh-41-20/
- https://holtecinternational.com/hh-41-23/
- https://holtecinternational.com/hh-41-03/
- https://world-nuclear-news.org/articles/holtec-smr-project-gets-regulatory-nod-for-early-site-work
- https://www.ans.org/news/2026-04-02/article-7901/holtec-hits-milestones-in-palisades-restart-new-reactor-projects/