Nine Mile Point Nuclear Station
Constellation Energy - Oswego County - NYISO
Two-unit nuclear generating station located at 348 Lake Road in Oswego, New York, on the shores of Lake Ontario. Unit 1 (613 MW, GE BWR-2) entered commercial operation on December 1, 1969. Unit 2 (1,277 MW, GE BWR-5) entered commercial operation on March 11, 1988. Constellation Energy owns Unit 1 (100%) and 82% of Unit 2; Long Island Power Authority owns the remaining 18% of Unit 2. Constellation operates the plant. The facility interconnects to the New York State Transmission System at the Scriba Substation at 345 kV. Unit 1 is currently licensed through August 22, 2029 and has a pending subsequent license renewal application; Unit 2 is licensed through 2046.
Overview
Key fields
- Nameplate capacity
- 1,901.1 MW
Canonical EIA plant baseline.
- Registry anchor
- Plant 2589
plant-2589
Structured profile
- Technology
- Nuclear
- Operator
- Constellation Energy
Units and generators
Operating generator records and technology attributes reported through EIA-860.
| Generator | Capacity | Technology | Operation | Status |
|---|---|---|---|---|
| 1 | 641.8 MW 621.4 MW summer | Nuclear Nuclear · ST | Dec 1969 | Operating |
| 2 | 1,259.3 MW 1,274.7 MW summer | Nuclear Nuclear · ST | Jul 1987 | Operating |
Performance
Monthly EIA generation history and recent market-resource behavior where linked telemetry is available.
Peer context
- Technology capacity
- 1,901.1 MW
- National rank
- #26
- NY rank
- #1
Monthly generation
Download CSVMonthly generation is reported through EIA-923. Capacity factor uses the current EIA nameplate capacity and is shown only for complete calendar years.
Grid and market context
Deterministic links to ERCOT market resources, price records, outage disclosures, queue records, and nearby infrastructure. Candidate joins remain labeled until corroborated.
Nearby substations
HIFLD infrastructure inventoryCommercial, land, and environmental record
Source-backed project transactions, agreements, land records, permits, and environmental disclosures. Portfolio and adjacent-project facts remain explicitly scoped.
Transactions and agreements
Related parties and identifiers
Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.
Relationship graph
Drag organizations to explore the network. Select a node to pin its details and available page link.
Parties and identifiers
| Relationship | Entity | Basis |
|---|---|---|
| Owner / operator | Owner and operator | |
| Owner | Long Island Power Authority | Co-owner of Unit 2 |
| Former owner | Niagara Mohawk Power Corporation | Former owner (41% of Unit 2) |
| Former owner | New York State Electric & Gas Corporation | Former co-owner (18% of Unit 2) |
| Former owner | Rochester Gas & Electric Corporation | Former co-owner (14% of Unit 2) |
| Former owner | Central Hudson Gas & Electric Corporation | Former co-owner (9% of Unit 2) |
| Operator | Exelon Generation Company, LLC | Operator of Unit 2 |
| Regulator | Licensing and regulatory authority | |
| Balancing authority / market operator | Market operator and balancing authority | |
| Transmission owner | Niagara Mohawk Power Corporation d/b/a National Grid | Connecting transmission owner |
| Transmission owner | New York State Electric & Gas Corporation | Connecting transmission owner |
| Equipment supplier | Equipment manufacturer | |
| Grid selection | plant:plant-2589 | Canonical asset page /nyiso/assets/plant/nine-mile-point-nuclear-station. |
Reporting portfolio
| Largest reported plants | Capacity | State | |
|---|---|---|---|
| Peach Bottom | 2,876.4 MW | PA | |
| Braidwood Generation Station | 2,449.8 MW | IL | |
| Byron Generating Station | 2,449.8 MW | IL | |
| LaSalle Generating Station | 2,340 MW | IL | |
| Limerick | 2,277 MW | PA | |
| Quad Cities Generating Station | 2,018.6 MW | IL | |
| Dresden Generating Station | 2,018.6 MW | IL | |
| Nine Mile Point Nuclear StationCurrent | 1,901.1 MW | NY |
Portfolio membership follows the latest EIA-860 reporting entity. It does not imply ultimate ownership.
View full reporting portfolioTimeline and sources
Project milestones and public references behind the asset profile.
Project timeline
- Unit 1 construction beganen.wikipedi...
Construction began for Nine Mile Point Unit 1
- Generator enters operationEIA-860
EIA-860 lists generator 1 with this operating date.
- Unit 1 commercial operationen.wikipedi...
Unit 1 entered commercial operation
- Unit 2 construction beganen.wikipedi...
Construction began for Nine Mile Point Unit 2
- Generator enters operationEIA-860
EIA-860 lists generator 2 with this operating date.
- Unit 2 commercial operationen.wikipedi...
Unit 2 entered commercial operation
- Constellation Acquisitionnucnet.org
Constellation Nuclear finalized the purchase of the two-unit Nine Mile Point plant for $815 million including fuel
- Unit 2 power upratepoweronline...
The NRC approved a 15% Unit 2 uprate, approximately 521 MW thermal and approximately 158 MW electric
- Operating responsibility assigned to Exelon Generationlipower.org
Operating responsibility for Unit 2 was assigned to Exelon Generation, while PSEG Long Island managed LIPA's interest
- Constellation Energy Corporation separationnrc.gov
Constellation Energy Corporation separated from Exelon and became the stand-alone owner of Nine Mile Point Unit 1 and Unit 2
- Unit 1 subsequent license renewal applicationnrc.gov
Constellation Energy Generation submitted an application seeking an additional 20 years of Unit 1 operation
- NRC accepted Unit 1 renewal application for docketingfederalregi...
The NRC published notice that the Unit 1 subsequent-license-renewal application was acceptable for docketing; docketing was not approval of the renewed license
Sources
Common questions about Nine Mile Point Nuclear Station
Answered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.
How big is Nine Mile Point Nuclear Station?
Nine Mile Point Nuclear Station has a reported capacity of 1,901.1 MW. Source: EIA Form 860M.
What kind of plant is Nine Mile Point Nuclear Station?
Nine Mile Point Nuclear Station is a nuclear facility in Oswego County, NY, participating in the NYISO market.
Where is Nine Mile Point Nuclear Station located?
Nine Mile Point Nuclear Station is in Oswego County, NY, inside the NYISO balancing area.
Who operates Nine Mile Point Nuclear Station?
Nine Mile Point Nuclear Station is operated by Constellation Nuclear according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.
How much electricity does Nine Mile Point Nuclear Station generate?
Nine Mile Point Nuclear Station reported 15,566.5 GWh over the twelve months to 2026-04. Figures are net generation as filed to EIA-923.
How does Nine Mile Point Nuclear Station compare to other plants?
By capacity, Nine Mile Point Nuclear Station ranks #26 of 54 operating plants of the same technology nationally. It ranks #1 of 3 in NY.
Co-located assets
Plants within 25 km, nearest first, regardless of technology. Proximity is straight-line distance between mapped plant coordinates; it does not by itself establish a shared point of interconnection.
Related assets
Similar plants ranked by technology, capacity, and distance.