Construction at Medupi had been suspended since January 17.
She said the power utility continued to engage with contractors to restore normal operations and emphasised that any labour disruption posed a serious threat to the project's tight schedule and could impact on Medupi's ability to meet its power generation deadline.
Meanwhile, Sapa reported on Friday morning that 46 people had been arrested for public violence at the Medupi site.
Workers initially embarked on illegal protest action on January 16, resulting in the injury of 25 workers and causing the subsequent lock-out of all employees owing to safety concerns.
The protest primarily involved workers affiliated to the metals industries and the National Union of Metalworkers of South Africa who were employed by Hitachi and Murray & Roberts Projects.