Duke Energy Carolinas is asking North Carolina regulators for permission to shelve a proposed nuclear expansion project and approve a $647 million rate hike, equal to a 13.6 percent increase across all customer groups.

Duke cited the March bankruptcy of Westinghouse Electric Co., a unit of Toshiba Corp., and other market activity in its decision to scrap the proposed two-unit nuclear project.

"Most notably, risks and uncertainties to initiating construction on the Lee Nuclear project have become too great and cancellation of the project is the best option for customers," a company statement says. Duke Energy says it will maintain the license to build new nuclear at this site in the future "if it is in the best interest of customers."

The William States Lee III Nuclear Station was a planned two-unit nuclear power plant with a combined generating capacity of around 2,234 megawatts. Duke Energy filed the Combined Construction and Operating License (COL) application for the plant in December 2007 with the Nuclear Regulatory Commission (NRC). In December 2016, the NRC issued two combined licenses authorizing Duke to build and operate two AP1000 reactors at the site. The development could have cost around $11 billion, sources said.

Duke Energy Carolinas serves two million households and businesses in central and western North Carolina. Duke Energy Progress, which serves electric customers in parts of central and eastern North Carolina and in the Asheville region, filed a similar request to adjust rates June 1.