The International Atomic Energy Agency (IAEA) has published its Safety Standard “Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries”.
According to the IAEA, the radiation risks to workers, the public and the environment that may arise from radioactive applications - such power generation, medicine, industry and agriculture - have to be assessed and, if necessary, controlled.
The agency said that a radioactive source that is not under regulatory control, either because it has never been under regulatory control or because it has been abandoned, lost, misplaced, stolen or otherwise transferred without proper authorization, is referred to as an orphan source.
The IAEA explained that such orphan sources have led to accidents with serious, even fatal, consequences as a result of the human exposure to radiation. The melting of an orphan source with scrap metal or its rupturing when mixed with scrap metal has also resulted in contaminated recycled metal and wastes.
If the contaminated material is not detected at the metal recycling and production facility, workers may be exposed to radiation and radionuclides may become incorporated into various finished products and wastes, which, in turn, may lead to the exposure of users of these products, the agency said.
In developing a new Safety Standard to address this issue, the IAEA said that it has assisted the United Nations Economic Commission for Europe (UNECE) in its efforts towards unifying and harmonizing both monitoring strategies for the detection of radioactive material in scrap metal and procedures to be used following the discovery of such radioactive material.
The IAEA safety standards reflect an international consensus on what constitutes a high level of safety for protecting people and the environment from harmful effects of ionizing radiation.
According to the Bureau of International Recycling (BIR), in addition to assigning responsibilities to governments and their regulatory bodies, the Safety Standard sets out certain responsibilities of operators in the metal recycling and production industries,
BIR said that for some time it has recognised the importance of addressing this issue and has been providing radioactivity advice on posters in ten languages (Arabic, Chinese, English, Finnish, French, German, Hindi, Japanese, Russian, Spanish) that fulfil certain responsibilities put by the Safety Guide on metal recyclers.
Recommendations
The Safety Guide recommends to apply a graded approach on the basis of the size of the individual metal recycling and production facility and on the radioactive material that it might reasonably be expected to encounter.
BIR said that in practice this means that small and medium sized facilities should have some awareness of the problem and be able to visually recognise suspect material and know who to contact in the event of a discovery.
However, the Bureau added that large facilities should be equipped with radiation detectors and should have sufficient radiation protection expertise available to undertake an initial response and to isolate suspect material.
According to the Safety Guide, irrespective of the regulations within any state, radioactive material may become mixed with scrap metal destined for recycling. However, scrap metal collectors, sorters and processors and the consuming metal works definitely do not want radioactive contamination entering their facilities.
BIR said that when operators find and isolate radioactive materials, they not only protect their workers and their facilities, but provide a service to society by protecting the public and the environment.
For international shipments of scrap metal, the Safety Guide requires that metal recyclers should provide a statement indicating whether the scrap metal has been subjected to radiation monitoring and the results of this monitoring.
In addition, operators of large facilities should conduct appropriate radiation monitoring to determine whether the scrap metal being processed and any resulting products such as ingots and metal bars etc. and wastes are safe.
Finally, BIR said that the Safety Guide resolves a contentious issue between sellers and buyers of scrap metal with the following statement:
“A statement from a supplier giving the results of radiation monitoring that has been conducted does not provide an absolute guarantee that the scrap metal does not contain radioactive material, in view of the difficulties of using monitoring equipment to detect and measure radioactivity in scrap metal. Therefore, monitoring of scrap metal entering a facility will still be necessary.”
