Radiation scare stories around the use of the Scannex low-dose X-ray scanner, which is used by many mining companies and was invented by diamond miner De Beers, were debunked during a media tour of De Beers’ Venetia mine, in Limpopo, last month. The system detects diamonds concealed in or on a person.
Botswana’s Debswana mines, which include Orapa, Jwaneng, Letlhakane and Damtshaa, are preparing to install ten Scannex machines at their operations.
The Scannex scanner produces a high-resolution digital image of any hidden hard material, such as a diamond, but not the soft tissue of a person in less than ten seconds. The scanning takes place in a safe and noninvasive manner. This method will replace invasive and time- consuming strip searches that are carried out daily in the high-security sections (diamond recovery plants) at Debswana’s operations.
The introduction of the Scannex machines has to date been approved by Botswana and the authorities implementing international standards but has been hindered by opposition from the Botswana Mine Workers Union (BMWU). There are also concerns linked to the possible effects that low doses of radiation could have on employees, especially pregnant women working in the mines.
Debswana received conditional approval from the Botswana Radiation Protection Board in June 2012 to implement the scanner and submitted an environmental impact assessment report to the Department of Environmental Affairs (DEA) in August last year.
“The DEA formed a review panel that is reviewing the submitted report,” Debsawana Mines senior project manager Eunice Mpoloko said during the Botswana media tour.
She added that Botswana’s Department of Health, the University of Botswana’s physics department, Botswana’s Radiation Protection Inspectorate and Botswana’s Department of Mines had written formal letters to the DEA in support of the R40-million project.
“However, unions have not given positive feedback regarding the implementation [of the Scannex machines], owing, we are told, to their concerns about harmful and excessive exposure to radiation,” Mpoloko noted.
Mpoloko told Mining Weekly that Botswana had become a global diamond hub for mining and trading and the cutting of rough diamonds, and since De Beers moved its aggregation of its worldwide production from London to Gaborone in 2012, there had been an increased need to improve security at its mines.
Independent consultant John Johnston said during the media tour that exposure to radiation through the Scannex machines posed no health risk to employees.
“The required limit of the ionising radiation dosage is 1 milli sievert (mSv) for members of the public and 20 mSv for employees who work with radiation. One Scannex scan is measured at 0.006 mSv, which is less than the radiation dosage used at airports and at medical facilities,” he said.
Johnson also commented that thousands of pregnant women were exposed to ionising radiation each year for medical and diagnostic purposes and that lack of knowledge was responsible for much of the anxiety regarding the safety of pregnant women.
“For most patients, radiation exposure is medically appropriate and the radiation risk to the foetus is minimal,” he said.
Johnson added that De Beers-owned mines had been using the Scannex machines for 20 years and that five-million scans had been recorded to date, with no incidents of overexposure to radiation.
“In terms of health, there is absolutely nothing whatsoever attributable to Scannex,” he said.
The process of implementing the scanner was a consultative matter between management and its stakeholders, which include the BMWU, and discussions were ongoing, Mpoloko concluded.