Industrial Irradiation for a Better World

Q: Is there a shift from irradiation using a radioactive source towards accelerator-based technologies?

A: There is a drive for this, and it mainly concerns the sterilization of medical devices where the demand for medical devices and hence sterilization is rapidly increasing. Irradiation is the preferred method for a little under half of the global volume of devices requiring sterilization, with gamma sterilization accounting for more than 80 per cent of these volumes. Various circumstances, some of which might be temporary, have recently prevented the cobalt-60 supply from keeping pace with the increase in demand. Medical device manufacturers usually have no preference for one method over another, they simply want their products properly sterilized. Gamma sterilization from cobalt-60 sources has two great virtues: simplicity and reliability. Accelerators also have advantages: the fact that only electricity is needed to power them and the possibility to pause the emission of ionizing radiation. The forces of the market will decide which of these technologies will be dominant in the future, but, for the moment, it is important that they all remain available because they are all needed to meet sterilization demand. It should be noted that, in terms of treatment capability, anything that can be treated by electron accelerators can be treated by gamma radiation, but the converse is not true. However, some accelerators can be fitted with a metal target that will convert the electron beam into X-rays which have characteristics similar to gamma radiation.

Q: Demand for accelerator-based industrial applications is growing, particularly in developing countries. What challenges do these technologies need to overcome to become more accessible?

A: It is likely that much of the growth of the traditional gamma irradiation market will go to accelerators in the future. The number of accelerator suppliers exceeds the number of cobalt-60 suppliers, but remains limited to a dozen or so for high-energy and high-power machines, and much less for accelerators with X-ray capability. The development of X-ray systems remains limited but is growing rapidly from a low base.

Accelerators have not yet been significantly adopted in many developing countries. The high investment required, the complexity of the machines compared to gamma irradiators, and the unavailability of an abundant and stable electricity supply are among the main reasons. Human resources, financial constraints, and fulfilling safety requirements are obstacles that could probably be overcome more easily than infrastructure and market size issues. For the moment, accelerator-based technology does not appear to be well-suited for all developing countries.

Q: The iia and the IAEA work together on different initiatives, such us international conferences and workshops for young researchers. How does this benefit the increased use of accelerator technology?

A: The objectives of the association align with some of the IAEA’s objectives. The iia is technology neutral in promoting the safe and beneficial uses of radiation technologies. While the counterparts of the IAEA are governments and their agencies, the iia mainly represents the industrial irradiation market. The iia collaborates with the IAEA in a growing number of initiatives.

Q: What accelerator-based industrial irradiation development are you most excited about? Would it be a ’game changer’?

A: In-line irradiation with low energy electrons and low energy X-rays is a very promising new approach. Based on the use of miniaturized accelerators or emitter lamps, this innovation could bring irradiation within the reach of manufacturers in many sectors. The penetration of low energy rays into materials limits potential applications, but the emitters have the advantage of being compact and can be integrated into manufacturing lines. Initial applications include the sterilization of syringes before filling in the pharmaceutical industry and the sterilization of materials at high speed on aseptic packaging lines for milk or soft drinks. Just to give you an example, a Swiss company has developed a machine for decontaminating food ingredients that is about the size of a large cabinet. Such systems are also used in pest control using the sterile insect technique, of which the IAEA is a champion, and for research in radiation biology. More efforts are required to expand the field of potential applications, especially using compact low energy X-ray systems, but there is little doubt that this might be a game changer.