Palo Verde Nuclear Generating Station

Palo Verde Nuclear Generating Station
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Name	Palo Verde Nuclear Generating Station
Country	United States
Location	Wintersburg, Arizona
Coordinates	33, 23, 21, N...
Owner	Arizona Public Service (lead operator)
Operator	Arizona Public Service
Construction began	1976
Commissioned	1986 (Unit 1)
Reactor type	Pressurized water reactor
Reactor supplier	Combustion Engineering
Turbine manufacturer	General Electric
Ps units operational	3 × 1,243 MWe
Ps electrical capacity	3,729
Ps annual generation	~31,000 GWh (2022)
Website	https://www.aps.com/en/About/Our-Company/Generation/Palo-Verde

Palo Verde Nuclear Generating Station is the largest nuclear power plant in the United States by net generation. Located in Wintersburg, Arizona, on a 4,000-acre site approximately 50 miles west of Phoenix, it is the only major nuclear facility in the world not situated adjacent to a large body of water. Owned by a consortium of utilities and operated by Arizona Public Service, the station's three identical pressurized water reactors provide critical baseload power to the Southwestern United States.

History and construction

The project was initiated in the mid-1970s by a partnership led by Arizona Public Service in response to growing electricity demand in the Arizona and Southern California regions. Construction began in 1976 under the prime architect-engineer Bechtel, with Combustion Engineering supplying the nuclear steam supply systems. The project faced significant challenges, including the 1979 energy crisis, the Three Mile Island accident, and subsequent tightening of Nuclear Regulatory Commission regulations, which contributed to delays and cost escalations. Unit 1 achieved criticality in 1985 and entered commercial operation in 1986, followed by Unit 2 in 1986 and Unit 3 in 1988. The station's unique wastewater reclamation system, developed in cooperation with the city of Phoenix, was a pioneering solution for its arid location.

Design and technology

Each of the three units utilizes a four-loop pressurized water reactor design from Combustion Engineering, with a rated thermal output of approximately 3,990 MWt. The reactor coolant system circulates water through the reactor core to the steam generators, which produce steam to drive General Electric-manufactured turbine generators. A defining technological feature is its use of treated effluent from several municipal wastewater treatment plants in the Phoenix metropolitan area, which is piped over 30 miles to the site for all cooling needs. The plant's containment buildings are of a large, dry sub-atmospheric design, and the facility includes extensive safety systems and robust spent fuel pool storage.

Operations and performance

As the nation's largest power producer of any kind since 1992, Palo Verde consistently achieves high capacity factors, often exceeding 90%, and generates over 30 million megawatt-hours annually. The electricity is distributed across the Western Interconnection grid, serving millions of customers in states including Arizona, California, New Mexico, and Texas. Operations are supported by a workforce of over 2,500 employees and long-term fuel supply contracts. The plant undergoes regular refueling and maintenance outages, typically on an 18-to-24-month cycle for each unit, which are coordinated with other generators in the Southwest Power Pool.

Safety and environmental impact

The station is regulated by the Nuclear Regulatory Commission, which conducts continuous oversight and detailed systematic assessment of licensee performance inspections. It has implemented numerous safety enhancements following events like the Fukushima Daiichi nuclear disaster, including the addition of FLEX mitigation strategy equipment and hardened ventilation systems. Its use of reclaimed water conserves billions of gallons of potable water annually in the Sonoran Desert. The plant maintains a comprehensive radiological protection program and its offsite consequence analysis emergency plans are coordinated with Maricopa County and the Arizona Division of Emergency Management.

Economic and community role

Palo Verde is a cornerstone of the regional economy, providing high-skilled employment, significant tax revenue to state and local governments, and stable, carbon-free electricity. Its output is critical for powering major population centers, data centers for companies like Google, and infrastructure across the Southwestern United States. The plant supports STEM education through partnerships with Arizona State University and local school districts, and its operators are active in community organizations like the United Way. As a low-carbon energy source, it plays a vital role in meeting the climate goals of owners like Salt River Project and the state of California.

Category:Nuclear power stations in Arizona Category:Buildings and structures in Maricopa County, Arizona Category:Pressurized water reactors