X-ray sterilization with accelerators is viable in US

David Kramer’s piece on gamma irradiators (Physics Today, August 2016, page 27 ) discusses the tricky position governments are in with respect to product sterilization facilities based on cobalt-60. Making current facilities safer and more secure directly addresses the threat of a radiological dispersion device based on ⁶⁰Co but might be seen as subsidizing the status quo. From the US industry perspective, however, practical steps taken today are not at odds with the demonstrated long-term commitment by the Department of Energy to curtail the commercial use of materials suitable for a dirty bomb.

Our group at Niowave Inc is an example of a private-sector effort to develop an alternative technology to large ⁶⁰Co-based irradiators. We build superconducting electron linacs with high-power x-ray converters for applications such as high-throughput sterilization. Kramer correctly noted that electron linacs are already showing that they will be cheaper in the long run for large sterilization facilities. And as the cost of building and operating those accelerators goes down, smaller operations will find it beneficial to switch.

The article concludes that accelerators for sterilization are somehow excluded from the US, and it implies that they get no help from the government. Neither of those assessments is fair. Niowave is developing linacs with direct financial assistance through a Small Business Innovation Research grant from DOE. The company has also benefited from participation in panel discussions like the Alternate Technology Working Group led by the Department of Homeland Security. Other groups are also receiving federal support and making progress in reducing radionuclide dependence—for example, in eliminating cesium-137 from blood irradiators and replacing americium–beryllium sources currently used for logging geologic formations when drilling wells.