Fleet by NRC Region · updated daily
Regions
The U.S. nuclear fleet across the NRC's four regulatory regions. As of Sep 15, 2026 · Updated every morning from the NRC Daily Power Reactor Status Report.
Online Now
11,362 MW
99.0% of 11,478 MW installed
Fleet Availability
99.0%
nuclear generating ÷ installed
Units in Outage
0
at a full outage (0% power)
Units Derated
1
running below 98% power
Region I
Northeast
King of Prussia, PA
100.0%
availability
3,352 MW
online of 3,352
0 MW
offline
3 units:
3 at power
Top markets
ISO-NE 3,352 MW
Region IV
West / South-Central
Arlington, TX
98.6%
availability
8,009 MW
online of 8,125
116 MW
offline
7 units:
6 at power
1 derated
Top markets
SRP 3,937 MW
CAISO 2,240 MW
SPP 1,948 MW
Region Summary
| Region | Coverage | Units | Capacity | Online | Availability | MW Offline | Offline / Derated | Top markets |
|---|---|---|---|---|---|---|---|---|
| Region I | Northeast | 3 | 3,352 | 3,352 | 100.0% | — | 0 / 0 | ISO-NE |
| Region IV | West / South-Central | 7 | 8,125 | 8,009 | 98.6% | 116 | 0 / 1 | SRPCAISOSPP |
NRC regions are administrative areas of the U.S. Nuclear Regulatory Commission, derived here from each plant's state. Availability = generating MW ÷ installed MW.
Fleet by Region
Every reporting unit, grouped by region, biggest supply loss first| Unit | Market | State | Power | Capacity | MW offline | Status |
|---|---|---|---|---|---|---|
| Region I · Northeast (3 units, 3,352 MW online) | ||||||
| Seabrook 1 | ISO-NE | NH | 100.0% | 1,246 | — | At power |
| Millstone 3 | ISO-NE | CT | 100.0% | 1,243 | — | At power |
| Millstone 2 | ISO-NE | CT | 100.0% | 863 | — | At power |
| Region IV · West / South-Central (7 units, 8,009 MW online) | ||||||
| Cooper | SPP | NE | 85.0% | 772 | 116 | Derated |
| Palo Verde 2 | SRP | AZ | 100.0% | 1,314 | — | At power |
| Palo Verde 3 | SRP | AZ | 100.0% | 1,312 | — | At power |
| Palo Verde 1 | SRP | AZ | 100.0% | 1,311 | — | At power |
| Wolf Creek 1 | SPP | KS | 100.0% | 1,177 | — | At power |
| Diablo Canyon 1 | CAISO | CA | 100.0% | 1,122 | — | At power |
| Diablo Canyon 2 | CAISO | CA | 100.0% | 1,118 | — | At power |
Ontario (IESO) separate fleet
Ontario detailMW Offline
3,632 MW
29.9% of the Ontario fleet
Units Offline
4 of 16
Bruce, Darlington, Pickering
Delivering
8,528 MW
of 12,160 MW installed
Resolution
1 hour
vs. once-daily for the U.S. fleet
Ontario is not an NRC region, so it sits outside the table above. Ontario is reported as a separate fleet and is never added into the U.S. national figures above. IESO grid-operator market data (MW delivered), not NRC percent-power.