Mining giant Rio Tinto is still trying to find out what caused a toxic spill at its Rossing Uranium mine in Namibia - the company's second major radioactive incident this month.
One of 12 leach tanks in the processing plant at Rossing in the Namib desert failed on December 3.
Rio said there was no environmental impact from the incident, with spilled slimes channeled in trenches and contained in a holding tank.
While the spill caused the milling operation to stop, it was expected to restart once the failed tank was isolated from the production process.
The company said some people received first aid at the scene, but no employees were seriously injured and production in other areas of the mine was not affected.
Rio's open pit Rossing mine opened 37 years ago and now produces four per cent of the world's uranium.
The Australian government has suspended processing operations at the Ranger mine in the Northern Territory after a leach tank with a 1.5 million-litre capacity burst and spilled out a radioactive and acidic slurry on Saturday.
Ranger is operated by Rio Tinto subsidiary Energy Resources of Australia.
Rio Tinto, a major shareholder in Rossing, said the operators of both facilities were offering "full support" as investigations into the incidents continue.
"Each company has commissioned a full investigation into these incidents to determine the cause and contributing factors," Rio Tinto said in a statement.
The company hopes the investigations will identify what caused or contributed to the Rossing incident.
Greens Senator Scott Ludlam said the Rossing acid spill was identical in nature to the Ranger spill.
"Rossing opened in 1976, Ranger in 1981 - both of these mines are ageing and failing," he said.
"Rio is now on the world's radioactive radar. In Namibia worker and environmental safety standards are much lower than at Ranger."
He said the industry was failing and it was time to shut down old mines.
The uranium price has been trading at record lows due to continued weak demand.
