# Data Center On-Site Nuclear & SMR

Canonical URL: https://menfem.com/kb/electrification/concepts/datacenter-onsite-nuclear-smr
Knowledge base topic: [Electrification](https://menfem.com/kb/electrification)
Frontier status: active
Tags: nuclear, smr, datacenter-power, onsite-generation, hyperscaler, behind-the-meter

---

This is the first coverage this KB has of on-site nuclear or small modular reactor (SMR) power for AI data centers — before this cycle, the electrification KB had zero prior sources on the topic despite it being a live, fast-moving hyperscaler capital-deployment story since 2024-2025. A continuously-updated industry-intelligence tracker puts committed hyperscaler nuclear/SMR capacity at **9.8 GW across 13 deals and 7 buyers** as of the May 2026 aggregate cut (1 project under construction, 12 in planning; underlying dataset last verified 2026-07-06).

The tracker's central finding is a clean split between two nuclear pathways with very different speed-to-power profiles: **restarting an existing, previously-licensed reactor is structurally faster than building a new SMR fleet.** Microsoft's Crane Clean Energy Center — the restart of Three Mile Island Unit 1, contracted with Constellation Energy for 835 MW under a 20-year, $16B power purchase agreement — is the fastest deal in the tracker, targeting full commercial power by **2027** after a FERC transmission-waiver approval cleared June 1, 2026. By contrast, **Meta's up-to-6.6 GW multi-developer portfolio** (spanning TerraPower's Natrium fleet, Oklo's Aurora SFR Power Campus, and PPAs with Vistra and Constellation) is the largest single commitment in the tracker but has the longest horizon, **2032-2035** — new-build SMR construction, even at hyperscaler capital scale, does not compress to a 2020s timeline.

This matters directly for how nuclear/SMR should be read against the near-term power-constraint story in [AI Data Center Grid Interconnection](./ai-datacenter-grid-interconnection.md): **nuclear is not, and will not soon be, an answer to the interconnection-queue and time-to-power problem through 2028.** Bloom Energy's concurrent industry survey (same discovery cycle) shows fuel cells (47%) and reciprocating engines/turbines (38%/33%) leading current onsite-technology evaluation, with nuclear barely registering as a near-term option — consistent with the deal tracker showing only one restart-class deal (Microsoft/TMI) landing before 2028, and every new-build SMR fleet (Meta/TerraPower, Meta/Oklo, Amazon/X-energy, Google/Kairos) clustering in the 2030s.

## Deal Table (as of May 2026 aggregate cut; tracker updates weekly beyond this cut)

| Buyer | Developer | Project | Reactor type | Capacity | Cost/value | Target date | Status |
|---|---|---|---|---|---|---|---|
| Microsoft | Constellation Energy | Crane Clean Energy Center (TMI-1 restart) | Large reactor restart | 835 MW | $16B PPA (20-yr) | 2027 | Under construction |
| Google | Kairos Power | 500 MW fleet | KP-FHR (fluoride-salt-cooled) | 500 MW | Undisclosed | 2030 | Planned |
| Amazon | X-energy / Energy Northwest | Cascade Advanced Energy Facility | Xe-100 HTGR | 960 MW (12 units) | $700M investment | 2030s | Planned |
| Amazon | Talen Energy | Susquehanna AI campus | Existing nuclear | Undisclosed | $20B+ | Undisclosed | Planned |
| Amazon | Dominion Energy | Virginia SMR development | SMR (type TBD) | Undisclosed | Undisclosed | Undisclosed | Planned |
| Meta | TerraPower | Natrium fleet (8 plants) | Natrium SFR | 4.0 GW | Undisclosed | 2032-2035 | Planned |
| Meta | Oklo Inc. | Power Campus (Pike County, OH) | Aurora SFR | 1.2 GW | Undisclosed | Undisclosed | Planned |
| Meta | Vistra | Nuclear PPA | Existing fleet | Undisclosed | Undisclosed | Undisclosed | Planned |
| Meta | Constellation Energy | Nuclear PPA | Existing fleet | Undisclosed | Undisclosed | Undisclosed | Planned |
| **Meta total** | — | — | — | **Up to 6.6 GW** | — | — | — |
| Equinix | Radiant Industries | Microreactor deployment | Kaleidos (1 MWe each) | 20 MW | Undisclosed | 2028+ | Planned |
| Data center operators (EU) | Last Energy | European fleet | PWR-20 microreactor | 1.6 GW | £300M (UK portion) | 2030+ | Planned |
| Data center operators (TX) | Last Energy | Texas fleet (Haskell County) | PWR-20 microreactor | 600 MW | Undisclosed | 2030+ | Planned |
| TBD AI data center | Aalo Atomics | Aalo Pod (INL area, Idaho) | PWR (50 MWe) | 50 MW | TBD | 2027 | Planned |

*Source: [Nuclear/SMR Data Center Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md), SMR.INTEL.*

## Key Claims

- **9.8 GW of nuclear/SMR capacity committed across 13 deals and 7 hyperscaler buyers**, as of the May 2026 aggregate cut. *Evidence: moderate* — single industry-intelligence tracker (analysis-grade, not peer-reviewed or regulatory-filed); treat as a snapshot, not a current total ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- **Restart-of-existing-reactor deals deliver power fastest**: Microsoft/Constellation's Three Mile Island Unit 1 restart targets 2027, the fastest date in the tracker, following a FERC transmission-waiver approval (cleared June 1, 2026). *Evidence: moderate* ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- **New-build SMR fleets cluster in 2030-2035**, regardless of buyer capital scale — Meta's TerraPower Natrium fleet, Oklo Aurora Power Campus, Amazon/X-energy Cascade facility, and Google/Kairos Power's 500 MW fleet all land in this window. *Evidence: moderate* ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- **Meta's up-to-6.6 GW multi-developer portfolio is the largest single commitment but has the longest timeline (2032-2035)** — illustrating the tracker's core trade-off: existing-reactor restarts deliver power fastest, new-build SMRs offer scale but not speed. *Evidence: moderate* ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- **Nuclear/SMR is not a near-term (pre-2028) answer to the AI-datacenter power constraint** — only one deal (Microsoft/TMI) lands before 2028; this is corroborated by Bloom Energy's concurrent survey, where nuclear barely registers against fuel cells (47%), reciprocating engines (38%), and mobile turbines (33%) in near-term onsite-technology evaluation. *Evidence: moderate*, cross-source corroboration between an analysis-grade deal tracker and a survey-grade industry report ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md); [Bloom Energy 2026 Report](../../raw/bloom-energy-2026-data-center-power-report.md))

## Benchmarks & Data

- Aggregate committed capacity: **9.8 GW** across **13 deals**, **7 buyers** (as of May 2026 cut) ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- Fastest deal: Microsoft/Constellation Crane Clean Energy Center (TMI-1 restart), **835 MW**, **$16B** 20-year PPA, target **2027** ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- Largest single-buyer commitment: Meta, **up to 6.6 GW** across 4 developers/structures, target **2032-2035** ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- Amazon/X-energy Cascade Advanced Energy Facility: **960 MW** (12 Xe-100 HTGR units), **$700M** investment ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- Projects under construction vs. planning: **1 vs. 12** ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))
- Tracker last verified: **2026-07-06**; aggregate totals as of **May 2026** ([Deal Tracker](../../raw/smr-nuclear-data-center-deals-tracker-2026.md))

## Open Questions

- **HALEU (high-assay low-enriched uranium) fuel-supply-chain risk is not quantified in this source.** Earlier (2025) industry writing flags Russian-supply linkage for HALEU enrichment; this cycle's tracker does not address it. This is a named knowledge gap (see [frontier.md](../frontier.md)).
- Many capacity, cost, and timeline fields in the deal table are marked "Undisclosed" (most of Meta's individual sub-deals, Amazon's Talen and Dominion deals) — true committed capacity and cost may be understated.
- The tracker is an industry-intelligence blog, not a peer-reviewed or regulatory-filed source — deal terms should be cross-checked against primary company disclosures (10-Ks, PPA filings) before use in any published report.
- Will any 2026-2027 restart or new-build slip past its target date? The Microsoft/TMI restart (2027) is the first real near-term test of nuclear's credibility as an AI-power source on the timeline hyperscalers are claiming.
- The tracker's "as of May 2026" aggregate will already be stale relative to its live (weekly-updated) state by the time this KB topic is next refreshed.

## Related Concepts

- [AI Data Center Grid Interconnection](./ai-datacenter-grid-interconnection.md) — The near-term (through ~2028) power constraint that nuclear/SMR does *not* solve; behind-the-meter gas and fuel cells are the technologies actually moving at AI-industry speed in this window, per Bloom Energy's survey. Nuclear/SMR is the 2030s-and-later generation-side answer to the same structural problem.

## Backlinks

*Pages that reference this concept:*
- [AI Data Center Grid Interconnection](./ai-datacenter-grid-interconnection.md) — cross-links here as the generation-side, multi-year-lagged counterpart to interconnection/curtailment mechanisms

## Changelog

- **2026-07-23** — New concept, first KB coverage of on-site nuclear/SMR for data centers. Compiled from 1 source (SMR.INTEL deal tracker, analysis-grade, snapshot as of May 2026, last verified 2026-07-06). Full 13-deal table reproduced; headline distinction is restart-of-existing-reactor (fast, 2027-2028) vs. new-build SMR fleet (scale, 2030-2035). Cross-linked to the new [AI Data Center Grid Interconnection](./ai-datacenter-grid-interconnection.md) concept as the near-term counterpart this concept does not address.

## Sources

- smr-nuclear-data-center-deals-tracker-2026

---

Cite as: MenFem Knowledge Base — https://menfem.com/kb/electrification/concepts/datacenter-onsite-nuclear-smr