COLUMBIA, SC — Utility engineers are working to seal cracks at a Fairfield County atomic power plant before the fractures widen and make the plant more vulnerable to a nuclear accident.
The SCE&G plant doesn’t present any current threat to the public, but cracks in the reactor head at the nuclear plant are a concern that must be addressed, according to the U.S. Nuclear Regulatory Commission.
Without repairs, the small cracks could widen and allow water that keeps the reactor cool to escape. In a nuclear plant, it is important to keep cool water circulating through the reactor to avoid a meltdown of atomic fuel and possible release of radiation.
In documents filed with the federal Nuclear Regulatory Commission, SCE&G says it plans to make repairs that will satisfy concerns about the recently discovered flaws at the V.C. Summer reactor. The repairs should be good for at least 40 years, the power company said in an Oct. 30 report to the NRC. The repairs have begun, a spokeswoman for SCE&G said.
But while nuclear industry watchdogs said they’re glad SCE&G found the flaws, they expressed worries about long-term safety.
Instead of sealing cracks in the aging reactor head, SCE&G should install a new head, as some other power plants have done, Columbia anti-nuclear activist Tom Clements said.
“The situation ... indicates to me that the best and safest fix is for the old, cracked vessel head to be taken out of service and replaced,” Clements said.
Both he and David Lochbaum, a national expert on nuclear plant safety, said the containment roof eventually could have other cracks. New reactor vessel heads could cost $40 million to $60 million, he estimated.
“At some point in the not-too-distant future, it seems like the company will want to replace the head with one that is a little more resistant to this kind of cracking,” said Lochbaum, who is with the Union of Concerned Scientists.
SCE&G’s nuclear plant, located about 25 miles northwest of Columbia, began operating in the early 1980s. The Midlands-headquartered power company is building two new reactors adjacent to the existing reactor. The new reactors are among only a handful approved for construction in the United States – the first to be built in 30 years.
At issue is a steel dome that sits atop a room surrounding the core of the nuclear plant, where atomic reactions occur to produce power. The reactor head is a smaller dome underneath the larger containment dome. SCE&G recently discovered flaws in four welded holes where nuclear fuel rods are inserted to control the atomic reactions.
Company spokeswoman Rhonda O’Banion said in an email Wednesday that SCE&G’s repairs are “preemptive to assure we have no issues in the future.” Repairs are occurring while the Summer plant is off line for refueling, something that happens about every 18 months. She characterized the reactor dome flaws as “minor defects.”
O’Banion did not say whether the company had long-term plans to replace the reactor vessel head, but NRC spokesman Roger Hannah said he believes the company will do so eventually.
Nationally, cracks in the domes of reactor vessels have occurred at other power plants, including Duke Energy’s atomic station in Oconee County near Seneca, said Lochbaum, who was in South Carolina this week to discuss flooding issues at the Oconee plant. The 2001 Oconee cracks were more serious than at Fairfield, he said. The discovery of the Oconee cracks prompted the NRC to require utilities to take a closer look for fractures at pressurized reactors like the ones at Oconee and Fairfield, Lochbaum said.
Lochbaum said, however, that SCE&G’s Summer plant never made the NRC’s list of plants most vulnerable to cracked reactor heads.