Seabrook

Nuclear power plant · Rockingham County, New Hampshire

Nameplate capacity
1,242 MW
Rank in New Hampshire
#1
of 61 plants
In service since
1990
August 1990

Details

Primary fuel
Nuclear
Technology
Nuclear
Operator
NextEra Energy Seabrook LLC
County
Rockingham County
Generating units
1
Share of state capacity
27.10%
Rank among nuclear plants in New Hampshire
#1 of 1
EIA plant code
6115

Generating units

Individual generating units at Seabrook
UnitTechnologyNameplateSummerOnlineStatus
1Nuclear1,242 MW1,247 MW1990Operating

Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.

Similarly sized plants in New Hampshire

Granite RidgeNatural gas790 MW
Newington Energy CenterNatural gas606 MW

About this data

From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 1,242 MW solar plant and a 1,242 MW nuclear plant have the same entry here and produce very different amounts of electricity.

“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All New Hampshire power plants · What New Hampshire actually generates