Exelon Generation said Wednesday that three nuclear plant workers have been diagnosed with COVID-19 since it took the Limerick Generating Station out of service for refueling March 27 — two since Friday — but the giant power plant is still on track to complete its maintenance turnaround early next week.

Of more than 1,000 workers involved with the refueling outage at Limerick’s Unit 1 reactor, 44 were quarantined because they may have come into contact with one of the infected workers or with infected people outside the plant, the company said in a statement Wednesday.

About 23 of the quarantined workers show symptoms, said Val Arkoosh, the chair of the Montgomery County Commissioners. Of the three people who have tested positive since the project began, one was a regular employee and two were contractors, she said.

“As the outage winds down, the number of workers onsite will continue to decrease significantly and we will remain overly cautious in our criteria for quarantining, including all workers — symptomatic or not — who have had potential exposure at work or at home,” Exelon said in a statement.

The company announced on Friday that one worker had tested positive, and said that two more were flagged this week. The workers were sent home to recover. Since the illness takes several days to incubate before a patient displays symptoms, it’s uncertain if the workers were infected on site or had come into contact with somebody before the outage began.

Two other Limerick staff members were diagnosed with coronavirus before the outage began but have not been on site since March 20.

About half the contracted workers are local and half come from out of state; specialists typically move like nomads among plants during the spring and autumn nuclear refueling seasons. Limerick is one of more than 30 reactors nationwide that are scheduled for refueling and maintenance outages this spring, according to the Nuclear Energy Institute.

Antinuclear activists have protested the influx of so many workers during a public health crisis, and Montgomery County officials have raised concerns about Exelon’s decision to proceed with the refueling.

Exelon characterized the number of infections as low, and said they have not impaired plans to refuel Unit 1′s nuclear fuel, an annual maintenance event at the twin-unit site. Because of the pandemic, Exelon had pared back planned Unit 1 maintenance to only essential tasks to reduce people on site during the outage.

“Maintenance activities remain on track, the fuel has been loaded, and we have a full complement of highly skilled workers on site to reassemble the reactor and complete the necessary tests and inspections safely and effectively,” the company said.

Staff writer Allison Steele contributed to this article