In a major blow to the future of nuclear power in the United States, two South Carolina utilities said on Monday that they would abandon two unfinished nuclear reactors in the state, putting an end to a project that was once expected to showcase advanced nuclear technology but has since been plagued by delays and cost overruns.
The two reactors, which have cost the utilities roughly $9 billion, remain less than 40 percent built. The cancellation means there are just two new nuclear units being built in the country — both in Georgia — while more than a dozen older nuclear plants are being retired in the face of low natural gas prices.
The South Carolina utilities selected an advanced reactor design from Westinghouse Electric Company, the AP1000, reported to have more safety features than earlier models. The utilities planned to build the two reactors next to an existing nuclear unit at the V.C. Summer plant in Fairfield County.
But pitfalls soon followed. Construction began before Westinghouse, a subsidiary of Toshiba of Japan, had finalized its AP1000 design, and several safety changes had to be made midway through the process. Engineers struggled with the complicated, novel project, as various components needed to be reworked.
In 2015, Westinghouse took over as lead contractor on the South Carolina project after buying out its partners, but analysts say the company did not have sufficient expertise in handling large construction projects.
In March, faced with mounting losses at its nuclear endeavors in South Carolina and Georgia, Westinghouse filed for bankruptcy. Toshiba agreed to pay $2.2 billion in exchange for being released from the South Carolina project, but utility officials said that was unlikely to be sufficient to finish the reactors.
Under South Carolina law, the utilities were allowed to charge ratepayers for construction costs before the reactors were finished. The nuclear project now accounts for 18 percent of the electric bills of South Carolina Electric & Gas’s residential customers. Santee Cooper, a state-owned utility, has increased rates five times to pay for the reactors.
Some environmental groups are now urging state regulators to refund those charges, arguing that the companies misled their customers.
“It was evident from the start that cost overruns, schedule delays and problems with an untested construction method” would doom the project, said Tom Clements, a senior adviser at Friends of the Earth. State regulators have set a hearing on the issue for October.
The two nuclear reactors still being built in Georgia are both AP1000s at the existing Vogtle nuclear power plant. Southern Company has agreed to take over construction of the Vogtle reactors in the aftermath of Westinghouse’s bankruptcy, but that project is also facing delays and overruns. The reactors will have to come online before 2021 to qualify for federal tax credits, although Congress is working on a bill to extend that deadline.