Nuclear power plant in Missouri, United States of America. Approximate location 38.7589, -91.7788.
NuclearMissouriUnited States of America
Callaway is a 1,275 MW nuclear power station in Missouri, United States of America. It is operated by Union Electric Co - (MO). Based on reported annual generation of 9,190 GWh, it can supply roughly 2.6 million homes. It ranks #480 of 10,938 United States of America power plants by installed capacity. Commissioned in 1985, it is around 41 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, nuclear supplies about 17.4% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0006153.
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
The capacity and/or fuel fields on this page include a source-backed provenance label from GEM, an official registry, Wikidata, OSM, or a cross-source match.
capacity: GEM tracker 2026 operating-unit sum (location L100000500053); fuel: WRI source-record fuel
At 1,275 MW, Callaway is below the median nuclear plant in United States of America (1,917 MW). Nuclear plants split uranium to raise steam with no direct CO₂; they run as steady baseload with very high capacity factors and the longest operating lifetimes of any thermal plant.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Operated by Union Electric Co - (MO). All plants by this company →
This nuclear plant uses heat from nuclear fission to raise steam for a turbine-generator. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 38.8°N — which shapes how much energy it can produce and how its output varies through the year.
Monthly mean temperature
Heating degree-days here run 7% above the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.
Climate heat-demand index: 53/100 — this site sits in the mid third of the power plants we cover by heating degree-days.
Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.
For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with humidity / wetness the leading environmental stress.
Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.
Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.
The #147 largest nuclear power plant of 230 in United States of America by capacity.
United States of America has 230 nuclear power plants in this dataset, together about 427,888 MW of capacity.
Coordinates 38.7589, -91.7788 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Callaway is a 1,275 MW source-record nuclear power plant in Missouri, United States of America, commissioned in 1985.
Callaway generates about 9,190 GWh of electricity per year.
Its output is enough to supply roughly 2,625,685 homes.
Callaway is operated by Union Electric Co - (MO).
