In this analysis
New, restored, incremental and preserved generation are different contribution categories; a capacity figure needs its baseline and expected date.
Preserved output and newly added nuclear output are different quantities. A new reactor, a dormant-plant restart and an operating-plant uprate start from different baselines. Counting their announced megawatts as though each were newly built generation would obscure what the agreements seek to change.
New construction has one baseline
The October 14, 2024 Kairos agreement concerned new nuclear development. Its baseline is the absence of operating generation from the proposed new project. This is a contribution category, not a statement that future output already exists.
The category matters before timing or price enters the comparison. A plan for a new asset differs from keeping an existing asset available. Similar firm-power objectives do not make the physical changes identical.
Restart has another baseline
The October 27, 2025 Duane Arnold announcement described an agreement aimed at reopening a dormant plant. The intended change is restored operation, not an entirely new reactor. The announcement does not establish a completed restart.
A restart can add supply relative to a dormant state while retaining a different project history from new construction. “Additional” therefore needs a named comparison. Additional relative to present nonoperation and newly constructed are not synonyms.
Uprates concern marginal output
The October 6, 2026 Constellation agreement supports operating-plant upgrades, with 890 MW of additional capacity expected by the end of 2032. The intended change is an increase above an existing operating baseline.
The source does not justify counting the whole preexisting plant as newly added capacity. Nor does the target mean the incremental output is already online. Quantity, baseline and expected date need to remain attached to one another.
A baseline ledger before aggregation
| Project class | Baseline | Intended contribution |
|---|---|---|
| New construction | No operating project output | New generation |
| Restart | Dormant output | Restored generation |
| Uprate | Existing operating output | Incremental generation |
| Life extension | Future retirement counterfactual | Preserved generation |
The last row is a comparison category, not another project claimed in the Constellation event. It shows why portfolio accounting needs a counterfactual as well as a headline capacity figure. Otherwise preservation can be mislabeled as construction, or whole-plant output mistaken for an incremental increase.
The causal conclusion
The chronology demonstrates several ways a buyer can support firm supply. Their contributions can all matter without being summed under an undefined “new nuclear” label. Transparent accounting states which baseline changes and when that change is expected.
Corporate inventory accounting illustrates identity discipline. Inference economics illustrates unit discipline. Applied here, those principles preserve the difference between existing assets, restored operation and incremental capacity. The result is a clearer portfolio argument without an invented realized total or a claim that every announced megawatt represents new construction.