The AP1000TM is a two-loop pressurized water reactor (PWR) that uses a simplified, innovative and effective approach to safety. With a gross power rating of 3,415 megawatt thermal (MWt) and a nominal net electrical output of 1,117 megawatt electric (MWe), the AP1000, with a 157-fuel-assembly core, is ideal for new baseload generation. The standardized reactor design complies with the Advanced Light Water Reactor Utility Requirements Document (URD).
Simplification was a major design objective of the AP1000. Simplifications in overall safety systems, normal operating systems, the control room, construction techniques, and instrumentation and control systems provide a plant that is easier and less expensive to build, operate, and maintain. Plant simplifications yield fewer components, cable, and seismic building volume, all of which contribute to considerable savings in capital investment, and lower operation and maintenance costs. At the same time, the safety margins for AP1000 have been increased dramatically over currently operating plants.
The AP1000 is comprised of components that incorporate many design improvements distilled from 50 years of successful operating nuclear power plant experience. The reactor vessel and internals, steam generator, fuel, and pressurizer designs are improved versions of those found in currently operating Westinghouse-designed PWRs. The reactor coolant pumps are canned- motor pumps, the type used in many other industrial applications where reliability and long life are paramount requirements.
The unique feature of the AP1000 is its use of natural forces - natural circulation, gravity, convection and compressed gas - to operate in the highly unlikely event of an accident, rather than relying on operator actions and ac power. Even with no operator action and a complete loss of all on-site and off-site ac power, the AP1000 will safely shut down and remain cool. Because natural forces are well understood and have worked as intended in large-scale testing, no demonstration plant is required. The Westinghouse advanced passive reactor design underwent the most thorough pre-construction licensing review ever conducted by the U.S. NRC.
Simplified Plant Arrangement