SCE&G forced to revise Summer schedule

South Carolina Electric & Gas (SCE&G) hopes to reach agreement by the end of this year on a revised schedule and cost estimate for a project to build two AP1000 units at its VC Summer nuclear power plant in Fairfield County, South Carolina.

SCE&G - which owns 55% of the project, while state-owned utility Santee Cooper holds 45% - will then file a request with the South Carolina Public Service Commission to approve the changes.

The Summer nuclear power plant currently consists of one unit - a Westinghouse-built 966 MWe 3-loop pressurized water reactor that was commissioned in 1984 and is licensed to operate until 2042. A Westinghouse/CB&I consortium is building two 1117 MWe AP1000 reactors at the plant.

The consortium recently informed SCE&G that the project faces delay of at least one year for each unit. The "substantial completion" of unit 2 is now expected in late 2018 or the first half of 2019, while that of unit 3 may be about 12 months later, SCE&G's parent company, Scana, said in a statement on 11 August.

Steve Byrne, SGE&G's chief operating officer, said in a conference call with analysts later the same day that "substantial completion" meant the point at which a unit is "up and operating" and the consortium "turns it over to its owners".

Cayce, South Carolina-headquartered Scana published a transcript of the conference call yesterday.

"It's important to understand that this information is preliminary and this range of dates does not reflect all the possible mitigation efforts, nor have we accepted this new timeline," Byrne said.

"The Base Load Review Act, or BLRA, provides that the Public Service Commission would grant the petition as long as it is determined that the change is not the result of imprudence on our part," he said.

Cause of delay

The "culprit" behind the delay, he said, is the fabrication and delivery of structural modules from the CB&I facility in Lake Charles, Louisiana.

One hundred out of the 146 construction milestones associated with the project have been completed, but many are being delayed because CB&I has yet to deliver a large structural module called a CA01, Byrne said.

As many as half of the construction milestones could fall outside the 18-month construction window allowed by state regulators under the existing guidelines for the project, he said.

CA01 will go inside the containment vessel and form cubicles for reactor internals such as steam generators, the refuelling cavity and the pressurizer, he said. Setting of CA01 is not a BLRA milestone, he added, but its delay is constraining other stages in the project that are BLRA milestones.

For instance, the CA03 module, effectively a large water tank that goes inside the containment vessel, cannot be installed before CA01, he said.

"I also have to get CA01 lifted and into the containment vessel. I can lift it over the first ring section, but I cannot lift it over two rings. So I'm constrained from putting the second ring section on the containment vessel," he said.

Other suppliers of modules have been contracted, Byrne said, including Oregon Iron Works in Oregon and Newport News Industries in Virginia as well as Toshiba Corp and IHI Corp in Japan.

Lake Charles will still be involved in the Summer project for some non-structural modules, but SG&E will otherwise be "de-scoping" the facility, Byrne said.

Scana stressed that the information received from the consortium did not include any revised cost estimates, which Byrne said the company expected to receive during this quarter.

Westinghouse/CB&I are also building two AP1000 units at the Vogtle nuclear power plant for Georgia Power Co, a subsidiary of Southern Company. Construction work on that is "neck and neck" with the Summer project, Byrne said.

There may be a "natural decoupling" of progress on those projects, he said, since they will use different cooling towers and they have different surfaces – Summer and Vogtle are hard rock and soft soil sites, respectively.

Researched and written
by World Nuclear News