A special inspection is underway after there was damage to a nuclear reactor that Chicago Bridge & Iron is building in South Carolina, federal regulators said Monday.

The damage to the reactor is another blow to CBI, which got into the nuclear project after acquiring The Shaw Group Inc., of Baton Rouge, in February 2013.

Last year, CBI agreed in a settlement with the U.S. Nuclear Regulatory Commission to better train employees at a Lake Charles factory making parts for nuclear plants after investigators accused three workers of cheating on a qualification test there. At the time of the infractions, the Lake Charles plant was owned by The Shaw Group.

In a news release Monday, the NRC said its representatives are launching a special inspection this week at the V.C. Summer Nuclear Station near Jenkinsville, about 25 miles northwest of Columbia.

Earlier this month, the NRC says, CBI workers cut rebar and damaged a containment vessel while drilling into concrete. Officials think the damage was minor but are concerned that it took the contractor a week to report it to SCANA Corp., which owns a 55 percent stake in the new reactors.

The NRC said inspectors will spend about a week at the site, and their report will be available within about 45 days. A SCANA spokeswoman said the company had already begun to address the issue and that the public was never at risk.

“With a construction project of this size and scope, we expect that there will be issues along the way,” Rhonda O’Banion said. “We will continue to address the issues with a firm focus on quality and safety.”

One reactor is already in use at the site, and Santee Cooper and SCANA are partnering to build two more. The new reactors have been estimated to cost nearly $10 billion and are among the first of their kind to be built in the United States in more than 30 years, slated to come online in 2019 and 2020.

The agency previously criticized the Lake Charles factory for discouraging workers from openly reporting problems and safety issues. NRC officials dropped a fine after CBI took steps to improve performance.

CBI’s factory was making parts for V.C. Summer and a nuclear plant under construction in Georgia. The firms building and designing those plants shifted production work away from the Lake Charles facility because utility executives and analysts said it struggled to meet NRC quality rules and produce key components on time.

NRC officials said the cheating did not cause any defective parts to leave the factory.

Before its acquisition by CBI, Shaw was building prefabricated submodules at the Lake Charles plant. Those subcomponents, including some that weigh many tons, were then shipped to South Carolina and Georgia and welded together. Utility officials said the process would increase quality and speed up construction.

But outside engineers monitoring the work said the construction of modules slipped because of design, fabrication and quality assurance problems. Officials said the company “clearly lacked experience in the nuclear power industry and was not prepared for the rigor and attention to detail required to successfully manufacture nuclear components.”