Cleanview

Nuclear power plants in ISO-NE

ISO-NE has 2 operating nuclear power plants with 3.5 GW of capacity.

  • Operating2

Under 250 MW250–999 MW1 GW and up

Updated monthly. Last updated November 2026.

The largest nuclear power plants in ISO-NE

Operating, by capacity

#Nuclear power plantYear onlineCapacity
1Millstone19862,260 MW
2Seabrook19901,242 MW

Nuclear power plants that came online most recently in ISO-NE

Newest first

#Nuclear power plantYear onlineCapacity
1Seabrook19901,242 MW
2Millstone19862,260 MW
The developer behind each project is on paid plans. See plans

How Cleanview tracks nuclear power plants

Operating nuclear power plants come from the EIA's monthly survey of power plants. Planned projects come from the grid operators' interconnection queues. We research who is developing each one, since a queue lists a project company, not its owner.

Questions about nuclear power plants in ISO-NE

How many nuclear power plants are in ISO-NE?
ISO-NE has 2 operating utility-scale nuclear power plants with 3.5 GW of capacity, according to the EIA's monthly survey of power plants.
What is the largest nuclear power plant in ISO-NE?
Millstone in New London County, Connecticut is the largest, at 2,260 MW. It came online in 1986.
How many nuclear power plants were built in ISO-NE in 2025?
0 nuclear power plants came online in ISO-NE in 2025, with 0 MW of capacity.
Who is developing nuclear power plants in ISO-NE?
Interconnection queues list each project under a project company, not the developer behind it. Cleanview researches the developer of every project and has them on paid plans.

More energy trackers for ISO-NE

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