NASHVILLE (AP) — A federal judge has limited the ability for now for the nonprofit running Oak Ridge National Laboratory to place employees on unpaid leave who receive exemptions to a COVID-19 vaccine requirement.

U.S. District Judge Charles Atchley in Knoxville issued the temporary restraining order Friday barring UT-Battelle from placing employees on indefinite unpaid leave or firing them after they receive a religious or medical accommodation to the vaccine.

The six workers who sued have argued they were told the unpaid leave would be indefinite. Their employer said in a court filing that the leave will last 60 days — with health benefits intact — and then will be reevaluated. Those with security clearances will maintain them for 90 days, the filing states.

Oak Ridge National Laboratory spokesperson Morgan McCorkle said Sunday that officials there "remain confident our policy is legal, in taxpayers' interest, and necessary for the well-being of our workforce."

The judge wrote that he will decide by Oct. 29 whether to let the order expire or keep it while the case plays out. He reasoned that "preventing their (employees') placement on unpaid leave for a matter of two weeks simply will not harm" the organization, while the unpaid leave presents a "functional loss of employment" and other damages for the workers at the lab, which is about 25 miles west of Knoxville.

The judge wrote that the order shouldn't be interpreted that he is inclined to block the order permanently, and instead was put in place to avoid the "risk of irreparable harm" until a full hearing can be held.

The employees sued earlier this month, saying they requested religious exemptions to the COVID-19 vaccine and two of them also asked for a medical exemption. The lawsuit also seeks class action status, arguing the unpaid leave policy breaches civil rights and disability discrimination protections.

The lawsuit says the workers were not offered alternatives, such as working remotely or periodic testing. All employees currently face a mask mandate at the lab.

The laboratory, which falls under the U.S. Department of Energy, announced on Aug. 26 that all staff needed to be vaccinated by Oct. 15, with a request that those who were seeking accommodations for religious or medical reasons to submit them by Sept. 15.

UT-Battelle had 145 employees request for accommodations for religious beliefs, and in 24 cases had in-person discussions with the workers. UT-Battelle received 75 requests for medical exemptions, granting 47 of them, denying 25, with three pending, a filing states.

According to the Oak Ridge National Laboratory website, there are 5,700 staff workers at the facility.

The organization discontinued the interviews after an employee on the interview list tested positive for COVID-19 on each of the two days, including one employee who was interviewed before receiving test results, "potentially exposing panel members to the virus," UT-Battelle wrote.

The nonprofit also said "the experience of late summer and early fall shows that testing does not adequately diminish the risk of onsite transmission," and that employees working from home were "not as effective as in person work" during the pandemic. The organization also noted that as a federal contractor, it falls under vaccination requirements in place through President Joe Biden's executive orders.

"The risk posed by unvaccinated staff members was exemplified by the employees who tested positive on the day they were being interviewed about their religious accommodation requests," UT-Battelle wrote.