The nearly $5.7 billion project to expand the V.C. Summer nuclear plant in South Carolina may continue to have problems with its modules, raising the possibility of more delays for the new reactors that are among the first to be constructed in the country in decades, according to a report from the South Carolina Office of Regulatory Staff.
The report, publicly released by state regulators April 7, came a few days after Summer majority owner and SCANA Corp. subsidiary South Carolina Electric & Gas Co. said that a key date for the installation of a module for Summer unit 2, the first of the two new reactors, has been pushed back.
Unexpected problems with fabricating the modules used to form much of the infrastructure for the reactors, such as failing to use the correct type of welding, have already delayed the other major nuclear project using the same Westinghouse Electric Co. LLC AP1000 reactor design, the Vogtle plant in Georgia. The delays also have played a role in a $900 million legal dispute between Southern Co. and the contractors building the modules for Vogtle.
These modules can weigh millions of pounds and are some of the largest components in the reactors.
According to the regulatory staff's report, the "critical path" to completing Summer unit 2 runs through two modules: CA20, which will serve as the auxiliary building next to the reactor's containment vessel, and CA01, the steam generator and refueling canal module. Project contractor Chicago Bridge & Iron Co. NV, or CB&I, has been putting together these modules, but delays in fabricating and delivering sub-modules have already pushed back the estimated completion of the reactors, increasing project costs by about $200 million, according to the report.
SCE&G has told regulators that CB&I will be transferring responsibilities to other vendors, a move the Office of Regulatory Staff said is a "positive step."
But the report still had reservations over whether the module difficulties have been resolved. "Although some progress has been demonstrated, fabrication of modules CA20 and CA01 remains the most significant challenge to meeting the project construction schedule," the report said.
For example, while the fabrication of the reactor's shield building module has been reassigned to Newport News Industrial, the new vendor's "sustained reliable performance has not yet been demonstrated" and a delivery schedule was not provided by the end of 2013.
In addition, also as of Dec. 31, 2013, no CA01 sub-modules have been delivered to the Summer site, meaning that meeting CA01's third-quarter 2014 "on-hook date," the date by which the CA01 module will be placed on the hook of a heavy lift derrick to be lowered onto the site, "will continue to be a challenge," the report said.
For CA20, "considerable progress" has been made toward meeting an on-hook date for the end of March 2014, the report said. But according to an April 1 update from SCANA, this date has been moved to May. SCANA said "various factors contributed to this modification, including inclement winter weather from two storms which closed the site for approximately a week, the incorporation of lessons learned from setting the same module at the Vogtle site a few weeks earlier, and CB&I performance and production related delays in aligning & welding of sub-modules."
It is unclear how the later installation of CA20 will affect Summer 2's schedule. SCANA spokeswoman Rhonda O'Banion said the schedule still indicates that, as previously announced, unit 2's completion could range from the fourth quarter of 2017 to the first quarter of 2018, with unit 3 to follow a year later. But the contractor consortium of Westinghouse and CB&I is currently "re-baselining" the schedule to come up with a more precise estimate, she said.
SCANA believes the delay will be less than 18 months, which is the amount of contingency time given to the project by the Public Service Commission of South Carolina when it originally approved the project in 2009, according to O'Banion. In its original order, the PSC said that SCE&G would have to go back to the commission and get new approval for any delays of 18 months beyond the project's substantial completion dates. In a 2012 order the PSC moved those completion dates to March 15, 2017, for unit 2 and May 15, 2018, for unit 3.
One piece of testimony the commission cited in its order touted the "modular" approach to building the reactors as a reason why they will be simpler and easier to build than past nuclear plants. "By designing the AP1000 as a 'modular' system of components and as a result of the passive nuclear safety features, the plant itself will require significantly less valves, piping, cabling, pumps and seismic designed buildings," according to 2008 testimony provided by Mark Crisp, an independent consultant serving the Office of Regulatory Staff at the time.
Despite the delays, the Summer project is actually slightly under budget. The gross construction cost, as approved by the commission, is $5.75 billion, but the current forecast is for $5.68 billion, according to the report.
SCE&G shares ownership of V.C. Summer with Santee Cooper, also known as the South Carolina Public Service Authority. The owners of the Vogtle plant are Southern subsidiary Georgia Power Co., Oglethorpe Power Corp., the Municipal Electric Authority of Georgia and the city of Dalton, Ga.