A power plant supplier looking to build components for small nuclear reactors is expected to announce Monday whether it will select Charleston or New Jersey, as the manufacturing site with nearly 400 workers.

The New Jersey site appears to be the frontrunner after the state's Economic Development Authority on Thursday approved $260 million in tax credits for Garden State-based Holtec International to build a 600,000-square-foot plant in Camden, across the Delaware River from Philadelphia.

The energy firm's founder, Krishna P. Singh, told the authority that without the tax credits, the company would build in Charleston. A filing with New Jersey officials calls Charleston "a lower cost option."

In a statement, Holtec called the deal "a great opportunity to make Camden a prominent industrial center in the Northeast." A Holtec official did not return calls for further remarks Friday.

The S.C. Commerce Department declined to comment.

The development of small reactors would put Holtec on a new path. It makes heat exchangers and condensers for power plants, equipment used to store spent nuclear fuel.

Holtec's tax-credit application with New Jersey says the new Camden facility could manufacture some of "its current line of nuclear products, heat exchange equipment, and other weldments for delivery to the company's customers worldwide." Nuclear fuel would not be stored on site.

The deal for Holtec International, said to be one of the largest tax-credit awards ever granted by the state, is expected to create 235 jobs and retain 160, according to the N.J. Economic Development Authority.

The retained jobs would be relocated from Evesham, N.J., where the company has its headquarters, according to New Jersey officials. Holtec also has a base in Jupiter, Fla.

Workers will earn a median wage of $86,265, according to the project summary. It is not known if the same wages would apply in South Carolina.

The Holtec deal, if it goes to New Jersey, is projected to net the state $155,520 over the course of 35 years - a time span set up by New Jersey law for tax credits in Camden, according to the project summary.

The company has to build the facility and hire employees before it can receive credits.

Singh, whose family has roots in the same part of India as Gov. Nikki Haley's father, has ties to the Palmetto State. In 2011, he contributed $3,500 to Haley's campaign and once, with business partners, considered building a smaller-model nuclear power plant at the federal Savannah River Site near Aiken, according to The Philadelphia Inquirer.

Haley supported Singh's proposal and called herself a family friend last fall as she attended dedication ceremonies for the $80 million Krishna P. Singh Center for Nanotechnology at the University of Pennsylvania, where Singh studied engineering.

Federal officials eventually turned down Singh's request to fund the model reactor.

Haley's office did not respond to a request for comment Friday.

Reach Warren L. Wise at 937-5524 or twitter.com/warrenlancewise.