The United States nuclear industry has started building its first new plants in decades using prefabricated Lego-like blocks meant to save time and money and revive the once promising energy source.
So far, it's not working.
Quality and cost problems have cropped up again, raising questions about whether nuclear power will ever be able to compete with other electricity sources. The first two reactors built after a 16-year lull, Southern Company's Vogtle plant in Georgia and Scana Corp's Summer plant in South Carolina, are being assembled in large modules.
Large chunks of the modules are built off-site, in an effort to improve quality and avoid the chronic cost overruns that nearly killed the nuclear industry when the first plants were built in the 1960s and 1970s.
Analysts say engineers created designs that were hard or impossible to make. The factory in Louisiana that constructed the prefabricated sections struggled to meet strict quality rules.
Utility companies got early warnings but proved unable to avoid the problems. Now the firms leading the project are phasing out the Louisiana factory on the biggest modules and contracting new manufacturers.
Few power companies are building new nuclear plants now in the US because gas-fired plants are so cheap by comparison. But if construction costs can be controlled, the nuclear industry might have a long-term chance. Future gas prices are always uncertain, and stricter US pollution rules could make nuclear plants more attractive since they produce no greenhouse gases.
The first of the two new reactors at each site in Georgia and South Carolina were supposed to be operating in 2016, but that has now been pushed out to 2017 or early 2018. In Georgia, Southern Co expects to spend US$646 million ($755 million) more than the budgeted US$6.1 billion on its share of the project.
Joseph "Buzz" Miller, a Southern Co executive tasked with building the nuclear plant in Georgia, thinks building in modules can still work, despite the recent trouble. "Has it for the first units resulted in a lot of time savings? No," he said. "But does it have promise? Yes."
Years ago, large workforces built nuclear power plants part by part. Using so much labour was expensive and difficult to manage. It increased the odds a work crew might make a mistake or fall behind schedule.
This time, the industry settled on a different technique. The utilities in Georgia and South Carolina purchased power plants that use the AP1000 reactor designed by Westinghouse Electric. Its modules can weigh hundreds of tonnes and dwarf buildings.
The Shaw Modular Solutions factory in Lake Charles, Louisiana, was to produce large, prefabricated chunks of the plants. The large sections are shipped to Plant Vogtle in eastern Georgia and the Summer generation station in South Carolina, where workers inspect them, weld them into large modules, then hoist them into place.
A nuclear engineer working for Georgia's utility regulators, William Jacobs jnr, warned in December 2010 that the Louisiana factory had experienced delays due to quality assurance, design and fabrication problems. He called it a "significant concern".
Inspectors for the US Nuclear Regulatory Commission halted their first review of the plant the following month, saying it was not ready for in-depth scrutiny. Follow-up inspections found more issues with the plant's quality assurance programmes.
NRC officials proposed a US$36,400 fine against The Shaw Group for firing a quality insurance supervisor who warned that a potentially faulty part may have been shipped to a project in New Mexico. The fine was dropped after the company agreed to changes. The agency also said workers at the Lake Charles facility feared raising safety and quality concerns to their supervisors.
The NRC concluded that a welder at the factory took a qualification test for another worker in 2010, and that a supervisor knew but did not report it.
"I think the Lake Charles facility is just on a learning curve that they can't seem to get on top of," said Anthony James, who monitors the South Carolina nuclear project for the South Carolina Office of Regulatory Staff, which oversees utilities.
Chicago Bridge & Iron Co acquired The Shaw Group in February 2013. It replaced top managers at the factory, adopted a less antagonistic stance toward inspectors and allowed Southern Co and Scana Corp to conduct more oversight.
The factory is now sending partially completed modules to the construction site to be inspected and repaired under the careful watch of the utility companies.
Westinghouse and CB&I are phasing out the Lake Charles factory and hiring firms in Oregon, Florida and Virginia to build the largest modules, Southern Co spokesman Brian Green said.