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.

West / South-Central

Arlington, TX

98.7%

availability

9,058 MW

online of 9,174

116 MW

offline

8 units: 7 at power 1 derated

Top markets

ERCOT 4,986 MW CAISO 2,240 MW SPP 1,948 MW

Region Summary

Region	Coverage	Units	Capacity	Online	Availability	MW Offline	Offline / Derated	Top markets
Region IV	West / South-Central	8	9,174	9,058	98.7%	116	0 / 1	ERCOTCAISOSPP

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 IV · West / South-Central (8 units, 9,058 MW online)
Cooper	SPP	NE	85.0%	772	116	Derated
South Texas 1	ERCOT	TX	100.0%	1,300	—	At power
South Texas 2	ERCOT	TX	100.0%	1,280	—	At power
Comanche Peak 1	ERCOT	TX	100.0%	1,209	—	At power
Comanche Peak 2	ERCOT	TX	100.0%	1,197	—	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 detail

MW 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.