AP1000

The AP1000 (Advanced Passive 1000) is a nuclear power plant designed and sold by Westinghouse Electric Company. The plant is a pressurized water reactor with improved use of passive nuclear safety and many design features intended to lower its capital cost and improve its economics. The design traces its history to the Westinghouse 4-loop SNUPPS design, which was produced in various locations around the world. (Note: System 80 was a similar vintage nuclear steam supply system made by Combustion Engineering.) Further development of the 4-loop reactor and the passively cooled containment initially led to the AP600 concept, with a smaller 600 to 700 MWe output, but this saw limited interest. In order to compete with other designs that were scaling up in size in order to improve capital costs, the design re-emerged as the AP1000 and found a number of design wins at this larger size. Seventeen AP1000s are currently in operation or under construction. Four are in operation at two sites in China, two at Sanmen Nuclear Power Station and two at Haiyang Nuclear Power Plant. As of 2019, all four Chinese reactors were completed and connected to the grid, and as of 2026, eleven more are under construction. Two are in operation at the Vogtle Electric Generating Plant near Augusta, Georgia, in the United States, with Vogtle 3 having come online in July 2023, and Vogtle 4 in April 2024. Construction at Vogtle suffered numerous delays and cost overruns. Construction of two additional reactors at Virgil C. Summer Nuclear Generating Station near Columbia, South Carolina, led to Westinghouse's bankruptcy in 2017 and the cancellation of construction at that site. It was reported in January 2025 by The Wall Street Journal and The State that Santee Cooper, the sole owner of the stored parts and unfinished construction, is exploring...