There are three reactors in Wintersburg, Ariz.: Palo Verde 1, 2, and 3. Wintersburg, which is about 50 miles west of Phoenix, has the only nuclear reactors in the state and is the largest nuclear site in the US. The first two reactors began operating at the plant in 1986, and the third began operating in 1988. “For years we’ve been looking at ‘what-if’ scenarios,” Randy Edington, the plant's chief nuclear officer, told Arizona's ABC15 TV in the wake of Japan's nuclear disaster. “I think the biggest thing is to go back and look at our emergency powers."