HAYWARD — Last year’s explosion at a power plant that started a fire and sent debris flying hundreds of feet was caused by too much water under pressure and high temperatures, combined with power plant operators not detecting the problem in time, investigators have determined.
The accumulation of water was the result of a gearbox failure that led to a valve not closing as it should, according to a letter from Calpine Corporation of Houston, which operates the site.
The Russell City Energy Center was shut down after the steam turbine explosion, but was allowed to resume partial operation on July 15 over the objections of local officials and residents. The state energy commission said the power generated by the plant (up to 350 megawatts) could be needed during expected heat waves last summer and fall as a backup. From Aug. 10 to Sept. 23, the center was called upon on 11 occasions to help meet energy demands.
The natural gas power plant is still not running at full capacity, though Calpine is hoping to make a return by summer.
“I know I speak on behalf of all of the commissioners that we were just appalled about the situation, and no lives were lost, but they could’ve been,” Commissioner Patty Monahan said at a California Energy Commission meeting Wednesday. “We recognize that, and so ensuring that we’re doing all we can to make communities safe as we provide power, is just sort of a core value of all of us.”
The steam turbine blew up just before midnight May 27, igniting a fire at the energy plant at 3862 Depot Road near the Hayward shoreline.
Although no one was injured, the explosion was so powerful it hurled a 15-pound metal piece through the roof of an unoccupied trailer at the city’s Housing Navigation Center at Whitesell Street and Depot Road, about 1,200 feet away. The center provides transitional shelter for homeless people.
Another piece of metal weighing 51 pounds landed at the city’s Water Pollution Control Facility at 3700 Enterprise Ave.
The cause of the explosion was determined through a joint investigation by the California Energy Commission and the California Public Utilities Commission. In October, representatives of the two agencies began meeting weekly to review the power plant situation. Investigators reviewed 100 documents, interviewed 12 witnesses and inspected the plant nine times. There also were three commissioner tours of the site and an audit.
“We have heard and we acknowledge the concerns raised by the joint agencies and the local community,” Michael Del Casale, senior vice president of operations for Calpine, wrote in a letter to the energy commission. “Calpine understands the need to take action to ensure that an event such as this never occurs again at Russell City or any other Calpine facility, and has developed a thorough plan to address the design issues that led to this event.”
After receiving approval to operate in a limited capacity, the power plant operators were ordered to meet with the energy commission staff and Hayward’s fire department to review and improve Calpine’s response to emergencies. Russell City will now coordinate with the Hayward Fire Department to have at least two general emergency drills and one mock rescue drill annually. In addition, the power plant staff will hold roundtable discussions with Hayward fire officials following the drills.
After the May explosion and fire was reported, every Hayward firefighter on duty was sent to the power plant while Oakland and Alameda County firefighters were called in for mutual aid to handle other calls.
In February, the joint agency team and independent consultants will do another inspection of the power plant. They will focus on equipment that was involved in the accident, the heat recovery steam generator system and any facility operations, maintenance and management practices that may have contributed to the explosion and fire.