Coronavirus Outbreak (copy) (copy)

This undated electron microscope image made available by the U.S. National Institutes of Health in February 2020 shows the novel coronavirus SARS-CoV-2.

The Savannah River Site, a sprawling nuclear reserve near Aiken, on Thursday reported 13 cumulative cases of COVID-19.

The 12th and 13th cases of the disease caused by the novel coronavirus were confirmed Wednesday, a U.S. Department of Energy spokesperson said. The 11th case was logged Tuesday.

The first case of COVID-19 at the Savannah River Site was recorded and disclosed in late March.

Nine Savannah River Site employees have recovered from coronavirus infection, the spokesperson continued, and have since returned to work. Whether that's in person or remotely – teleworking, for example – is unclear.

Roughly 10,000 people are employed at the Savannah River Site, which neighbors New Ellenton, Jackson and the Georgia state line. Fewer than 2,500 are currently reporting to work at the site, as SRS operates under an essential mission-critical condition amid the coronavirus crisis.

"Due to the nature of what we do, we cannot just walk away and turn off the lights," Savannah River Nuclear Solutions President and CEO Stuart MacVean wrote in a memo to employees earlier this year. "Please remember that many employees cannot just go home."

More than 5,800 cases of COVID-19 have been confirmed in South Carolina. Ninety-seven cases were confirmed in Aiken County as of Wednesday afternoon. 

Colin Demarest covers the Savannah River Site, the U.S. Department of Energy, the National Nuclear Security Administration and government in general. Follow him on Twitter: @demarest_colin