One of the Comanche Peak nuclear power plant’s two units has been offline for more than a week following a June 7 fire in the main transformer, putting pressure on the Texas power grid and contributing to this week’s plea for statewide conservation.
The plant’s shutdown worsened the power grid-capacity crunch that triggered the Electric Reliability Council of Texas to call for energy-saving measures through Friday. ERCOT recommends raising thermostats to 78 degrees or above and avoiding the use of large electronics like ovens and washing machines.
The cause of the fire at the plant near Glen Rose remained under investigation Tuesday, said Victor Dricks, senior public affairs officer for the U.S. Nuclear Regulatory Commission. Unit one is at full capacity while unit 2 is shut down.
Each unit of the plant, owned by Irving-based company Vistra Corp. and located 60 miles southwest of Dallas, can put out about 1,150 megawatts when operating at full capacity, according to NRC data. That’s enough electricity to power 1.15 million homes during normal conditions and up to 460,000 additional households during peaks.
The fire, which began around 3:30 p.m. on June 7, was extinguished within 20 minutes and without major injuries, according to an NRC event report. It took place in the plant’s main transformer, which is located outside of the buildings that house the pressurized water reactors
“The reason the plant is still shut down is because [Vistra] ... is still investigating exactly what happened and what they need to do to repair that transformer,” Dricks said. “This plant has not had an unusual number of shutdowns.”
The 2.3-gigawatt Comanche Peak plant, one of the nation’s newest, began supplying power to the state’s grid in August 1990. It’s one of two nuclear power plants in the state that supply a combined 11% of ERCOT’s electricity annually.
“We are working diligently to repair the transformer in order to bring the unit back online — there are no issues with the unit itself,” said Meranda Cohn, senior director of communications and media relations at Vistra.
Nuclear plant fires can result in extensive damage and lead to prolonged shutdowns.
“Depending on the extent of the damage, it could be a fairly long time,” said Edwin Lyman, director for nuclear power safety at the Union of Concerned Scientists, a nuclear safety watchdog group. “We just don’t know.”
On Monday, ERCOT said it set a new June record for electricity demand. Based on preliminary data, demand totaled 69,943 megawatts, topping a previous record set in June 2018. Demand had dropped to 67,383 megawatts by 6 p.m. Tuesday, according to real-time data on ERCOT’s website.
ERCOT reported forced outages Monday of about 12,000 megawatts at generating plants, enough to power more than 2 million homes. About 9,000 of those megawatts come from thermal power sources fueled by natural gas, coal or nuclear power.
About 1,200 megawatts of power was regained Monday night when repairs to some plants were completed. ERCOT said Tuesday that the grid is operating as it was designed and urged Texans to continue conserving electricity during the peak hours of 3 to 7 p.m. through Friday.
Fears of widespread power outages are high among Texans following the February winter storm that left millions without electricity and led to at least 133 deaths. It’s now the second time since that storm that ERCOT has asked state residents to conserve.
As months of more summer heat loom, the grid’s ability to sustain Texans’ energy needs is becoming increasingly important.
“This is a priority to ensure that generators can perform as we head into summer months,” ERCOT spokeswoman Leslie Sopko said Monday. “We are immediately working to mitigate this risk.”