Jacksonville, Fla.'s municipal electric utility has agreed to pay $7.5 million for an option to become part owner of Duke Energy's proposed Lee nuclear power plant near Gaffney, S.C.

A filing with the N.C. Utilities Commission says the utility, JEA, will have the option to buy a 5 percent to 20 percent interest in the plant. JEA will have 90 days after Duke receives a federal construction and operating license for the plant to decide whether to exercise the option.

The plant, which would be Duke's first nuclear plant since the mid-1980s, is scheduled to start operating in about 2020.

In written testimony filed this week with the utilities commission, Duke CEO Jim Rogers called the option "a strong step forward" for the plant. Rogers said it is a first step toward bringing in partners to share the massive expense and risks of building new nuclear plants.

Duke has twice pushed back the start-up date of the Lee plant, which was first projected to launch in 2016. Duke has estimated costs of the two-reactor plant at $11 billion, based on industry estimates.

"In addition to the benefits of risk sharing, additional partners on the project will increase the financial flexibility the company needs to meet customer demands in the face of tremendous uncertainty relating to future environmental constraints that will impact its current fleet," Rogers said in the filing.

Duke itself will need all the output of the Lee plant, Rogers said, and could become a partner in other regional nuclear plants to fill its needs.

Raleigh-based Progress Energy, with which Duke announced a merger last month, has also planned to build new nuclear plants near Raleigh and in Florida.

JEA serves more than 417,000 electric customers in Jacksonville and parts of three adjacent counties. It operates three power plants.