Three Mile Island nuclear power plant 1
Retired United States
Gross capacity
880MW
Three Mile Island nuclear power plant 1 is a pressurised water reactor unit at Three Mile Island nuclear power plant in United States rated at 880 MW gross. It is retired. Commercial operation began 2 Sep 1974.
Specification
| Reactor type | Pressurised water reactor (PWR) |
|---|---|
| Model | B&W LLP (DRYAMB) |
| Size class | Large |
| Coolant | Light water |
| Moderator | Light water |
| Gross capacity | 880MW |
| Net capacity (reference) | 819MW |
| Net capacity (design) | 819MW |
| Thermal output | 2,568MWt |
| Typical enrichment | 3–5% U-235 |
Ownership & location
| Site | Three Mile Island nuclear power plant |
|---|---|
| Unit | 1 |
| Country | United States |
| Owner | Exelon Corp100% |
| Operator | Exelon Generation |
| Coordinates | 40.1539, -76.7248 |
Fuel chain for this unit
Fuel form
Uranium dioxide pellets in zirconium-alloy cladding
Enrichment
3–5% U-235
Who makes this assembly
- China National Nuclear Corporation PWR fuel assemblies
- ENUSA Industrias Avanzadas PWR and BWR fuel assemblies
- Framatome PWR fuel assemblies
- KEPCO Nuclear Fuel PWR fuel assemblies
- Mitsubishi Heavy Industries PWR fuel assemblies
- Westinghouse Electric Company PWR fuel assemblies
Upstream
Enriched fuel means this unit sits downstream of five conversion plants and four enrichment operators holding 88% of world capacity between the top three.
Fabricator capability is recorded against reactor type and model line, not against named units —
utilities do not publish fuel contracts. See the fuel chain.
Timeline
- 18 May 1968Construction start
- 5 Jun 1974First criticality
- 19 Jun 1974Grid connection
- 2 Sep 1974Commercial operation
- 20 Sep 2019Permanent shutdown
Other units at Three Mile Island nuclear power plant
| Unit | Status | Gross MW |
|---|---|---|
| Three Mile Island nuclear power plant 2 | Retired | 959 |
| Three Mile Island nuclear power plant Unit 1 Repower | Pre-construction | 880 |
Other B&W LLP (DRYAMB) units
7 units worldwide share this model designation.
| Unit | Country | Status | Gross MW |
|---|---|---|---|
| Arkansas Nuclear One nuclear power plant 1 | United States | 903 | |
| Oconee nuclear power plant 1 | United States | 891 | |
| Oconee nuclear power plant 2 | United States | 891 | |
| Oconee nuclear power plant 3 | United States | 900 | |
| Crystal River nuclear power plant 3 | United States | Retired | 890 |
| Three Mile Island nuclear power plant Unit 1 Repower | United States | Pre-construction | 880 |
Sources
- Global Nuclear Power Tracker, Global Energy Monitor, August 2026 release — CC BY 4.0 · retrieved 2026-09-06 · this unit last researched by GEM on 2024-05-29
- GEM.wiki entry (further reading) — CC BY-SA 4.0 — linked, not quoted