Management of the Chernobyl nuclear power plant, site of the world’s worst nuclear accident in 1986, said that 50 staff members who had been on the job since the plant was seized by Russian forces on February 24 have been rotated out and replaced.

Officials had repeatedly expressed alarm that the staff were suffering from exhaustion after weeks of forced, unrelieved work.

This endangered the decommissioned plant’s safety, officials added.

The authority that manages the plant did not give specifics on how agreement was reached to let the workers leave and others come in to replace them.