Palo Verde nuclear power plant continues to defy desert
TONOPAH – Many scientists and engineers consider the Palo Verde Nuclear Generating Station to be a feat of engineering because it’s not near a large body of water – unlike other nuclear power plants around the world.
Mike McLaughlin, general manager at Palo Verde, has worked at the plant for four years. He said the plant, in commercial operation since 1986, produces power for about 4.1 million people across regions in New Mexico, Texas, California and Arizona.
The plant’s three nuclear reactors each require 20,000 gallons of water per minute.
But much of the Southwest faces a drought. So where does the water come from?
The vast majority comes from wastewater. The power plant’s wastewater comes from Phoenix’s 91st Avenue wastewater treatment facility and Tolleson’s facility. The water moves through about 36 miles of pipe before it reaches the plant in Tonopah.
The nuclear fission process creates incredible amounts of heat, so when the reaction takes place under water, a heavy mass of vapor rises to generate turbines and therefore, electricity.
“If we bring a drop of water to Palo Verde, it either evaporates off or it stays here forever,” McLaughlin said. “We’re a zero-discharge station, which is a little bit unusual since most stations are near the ocean or a river, and they’re pumping water into and out of the station.”
He said he likes to watch the vapor stream out like giant chimneys.
“(The) higher the humidity and lower the temperature, the bigger the plume coming from the cooling towers,” McLaughlin said.
McLaughlin said each of the turbines within the reactors generate 1,400 megawatts of power, or about 1.7 million horsepower.
“That can get a little confusing. I mean, a high-performance sports car only generates just a few hundred horsepower,” he said.
Seven southwestern companies own the plant, but APS owns the largest share – with about 30 percent – so it takes the most responsibility for the oversight and upkeep of resources.
Although the plant relies mostly on effluent, about 3 percent came from groundwater in 2013, according to APS.
Robert Lotts, water resource manager for APS, said his company carefully monitors water levels throughout the state so they can reimburse municipalities for water APS purchases.
“They have dams where they measure the depth,” Lotts said. “We have actual flow measuring technology, too, so we can see how fast water is moving.”
Lotts said the company is concerned about the state’s drought, but he thinks the current system saves potable water while making the most of treated wastewater.
At peak operating capacity, Lotts said the plant uses about 80 million gallons of water to generate power during a typical hot day in July or August. According to APS records, at 5 p.m. on Aug. 5, about 1.2 million APS customers used more electricity than at any other time in 2015.
“The summer is when people need power most,” McLaughlin said.