The South Texas power plant today.
Tomorrow (Saturday, March 8) will mark a unique milestone for the Texas power industry — the twenty year anniversary of the first sustained reaction of a nuclear power reactor in the state.
At 5:08 a.m. on March 8, 1988 Unit 1 at the South Texas Project near Bay City (called the South Texas Nuclear Project back then) “went critical … after a long night of gentle nudging by control room operators,” wrote the Houston Post’s environmental writer Harold Scarlett in a March 9 article. “Criticality occurs when a reactor reaches a self-sustaining chain reaction.”
“The STNP operators finally “tickled the dragon’s tail,” as some physicists call a reactor startup, after numerous delays and diversions. These included an erroneous temperature reading 10 days ago that halted an earlier startup attempt and a wildcat work stoppage by construction crews last week.”
Five of the ten control room engineers at the time still work at the plant, STP said in a release it put out this week:
“It was exhilarating,” said Tim Bowman, who was the night shift technical advisor in the control room 20 years ago and one of the witnesses of Unit 1’s initial criticality. “That’s what we got into the business to do -build a nuclear reactor and watch it work.”
Reactor operator Greg Chitwood had the responsibility of making the official call for when Unit 1 was producing a sustained nuclear reaction, but from his work station he couldn’t see a set of controls that actually gave an earlier indication of the reacton, Bowman said.
“So we’re back there and watching and going, ‘Yup, it looks like the reactor is critical, it looks like the reactor is critical,’ but Chitwood has to be the official one to call it.”
Current workers who were there in 1988: From left, Tim Bowman, general manager of oversight; Roland Dunn, Jr., supervisor of configuration control and analysis; Greg Chitwood, senior reactor operator license training instructor; Jesse Wells, work control manager; and Bernie Neurohr, senior reactor operator license training instructor. (Photo courtesy of STP).
More from the Post’s description of the process:
To activate the Unit l reactor, operators first injected a heavy dose of boron in the cooling water circulating around the reactor’s 193 uranium fuel assemblies. Boron slows the atom-splitting fission process and controls the nuclear reaction.
With the pressurized reactor water at the designed operating temperature of 567 degrees, the operators then slowly began withdrawing the reactor’s control rods about 10:30 p.m. Monday. At about 12:15 a.m. Tuesday, they slowly began diluting the boron with pure water to speed up the reaction.
A set of 29 special control rods, used for “fine-tuning” the nuclear reaction, can be withdrawn from the reactor in 5/8-inch steps through a total of 259 stops.
At 5:08 a.m., the number of neutrons being released in the nuclear reaction exactly equaled the number being absorbed by the boron, the partially removed control rods and other neutron absorbers. A self-sustaining chain reaction was achieved.
Today, the plant’s two reactors generate about 7.5 percent of the state’s power. Operators have applied to add two more reactors to the plant.