Long-delayed projects designed to protect the Oconee Nuclear Station from catastrophic flood are on schedule, and plans for new “major modifications” will come forward in the coming months, the station’s owner said Wednesday.
For the first time, Duke Energy publicly shared new proposals to divert rushing waters away from the three reactors in case the 385-foot-high Jocassee Dam were to ever fail upstream. Oconee nuclear is on Lake Keowee near Seneca, SC.
The fixes — some of which the company said might prove too costly — would occur not to the Jocassee Dam but to the Keowee Dam and areas of the station, Duke officials told Nuclear Regulatory Commission (NRC) regulators Wednesday in Atlanta.
Duke will formally submit the proposals in December, company officials said.
Meanwhile, other ongoing safety projects — including one designed to provide backup power in case of flood — will meet their newly revised deadlines, the company said.
Earlier this year, the NRC warned Duke the agency could impose civil fines for the company’s delays in completing safety projects.
The agency ruled against imposing fines so Duke could complete the backup power system, known as the “protected service water system,” originally scheduled to wrap up in 2010.
Over the summer, the NRC extended the deadline to 2016 for the backup power system and alterations to the station’s fire-protection plans.
In its presentation, Oconee site vice president Preston Gillespie assured regulators they “won’t be before them asking for forgiveness” in 2016 for not completing the projects and the company has had a new sense of accountability in the first part of this year.
Eric Leeds, director of the NRC’s Office of Nuclear Reactor Regulation, said the agency hopes the company can follow through.
“At this point we are very encouraged by what Duke is doing and very positive about how they’re attacking this issue,” Leeds said. “However, the devil is in the details.”
After the protected service system wraps up, Duke will work on new safety measures to protect against flood, Oconee licensing manager Dean Hubbard said.
The proposals include a discharge diversion wall at the west end of the Keowee Dam and an isolation drain structure in the station’s turbine building to prevent water from infiltrating.
The company also proposed “armoring” the east bank power block and the intake dike to the south of the station. The armoring would involve installing interlocking concrete blocks braced with cable anchors.
Duke ruled out an expensive “hardening” of the bulk of the Keowee Dam, which would involve applying roller compacted concrete.
The final determination on what fixes to implement will come after the company completes its flood hazard analysis required by the federal government in response to the 2011 tsunami-spawned Fukushima nuclear disaster in Japan.