The Times of India, quoting the director of the Kakrapur Atomic Power Station in eastern Gujarat state, said the labourers were working on a spent fuel duct when radioactive material was accidentally released into it.
"They were sent home as they were within our radiation limits," said director K.P. Dutta, who added that the men had been examined at the plant's hospital.
Their radiation exposure was 90 millisieverts, he said, which is only slightly higher than the 60 millisieverts sustained during a full-body medical scan.
Two workers in the control room responsible for the accident have been removed from their positions, Dutta said.