"South Africa boasts a nuclear research reactor facility at Pelindaba that produces nuclear medicine, which gets injected into a patient on average every three seconds in more than 60 countries," Zuma said at the Energy Indaba in Midrand on Thursday.

On Wednesday, South African Nuclear Energy Corporation (Necsa) spokesperson Nikelwa Tengimfene told News24 that, since the production line of radioisotope cancer treatment at the Pelindaba nuclear plant was halted in November, the corporation has been losing about R3.5m every day.

Necsa produces radioactive atoms for medical purposes, and cancer patients in 60 countries depend on its products.

Local facilities that receive isotopes include the Steve Biko and Charlotte Maxeke hospitals in Gauteng.

Tengimfene said at the time that, although production at NTP Radioisotopes - a Necsa unit - remained closed, Necsa had made contingency plans for cancer patients to receive medication.

She said safety concerns after the machine malfunctioned caused the stop in production.

The matter was reported to the National Nuclear Regulator (NNR), which advised Necsa to stop all operations immediately.

Since the incident, three Necsa senior executives have been placed on special leave.

Necsa would make an announcement on production resumption in due time, Tengimfene said on Wednesday.

At Thursday's Energy Indaba, Necsa CEO Kelvin Kemm sang the praises of the reactor itself, saying that the facility ran 24-hours a day, seven days a week.

"We are extremely proud of this and the people who operate it," Kemm added.

Tengimfene and presidency spokesperson Bongani Ngqulunga could not be reached for comment.

*Additional reporting by Yolandi Groenewald

News24