The use of high-risk radioactive materials in medical, research, and commercial applications has increased by about 30 percent in the U.S. in the last 12 years, and the government should improve security, tracking, and accountability to reduce health and security risks — while also supporting the development of nonradioactive alternatives to replace them — says a new report from the National Academies of Sciences, Engineering, and Medicine. Radioactive Sources: Applications and Alternative Technologies says the U.S. Nuclear Regulatory Commission’s (NRC) system for categorizing and regulating these radioactive materials fails to adequately protect society, and should be overhauled to take into account the long-term health impacts and socio-economic effects of possible misuse or malicious use — such as a “dirty bomb” scenario.
Radioactive materials are used commercially in a wide range of applications, such as treating blood before transfusion, sterilizing medical devices, treating cancer, exploring geological formations, and finding oil and gas deposits. The responsibility of securing these materials falls to the universities, hospitals, and commercial facilities that use them. If these materials are mishandled, or if they are used maliciously, they have the potential to cause billions of dollars of damage in economic impact, cleanup, and loss of access to affected areas — even if only small amounts of the material are involved.
A previous National Academies report on commercial applications of radiological materials published in 2008 called on the government to accelerate replacement of cesium chloride — a material of greater concern than other radiological sources — because it was widely used, soluble, and dispersible, and therefore at risk of being used in terrorism. The new report published today finds some progress has been made since 2008 in replacing cesium irradiators with X-ray technology for blood treatment and research. However, no progress has been made in replacing cesium chloride from applications such as calibration systems used for radiation monitoring equipment.
“It is clear that more work needs to be done to encourage and support universities, hospitals, and industry to voluntarily replace their radioactive materials with safer alternatives,” said Thomas Kroc, chair of the committee that wrote the report, and applications physicist at Fermi National Accelerator Laboratory. “Our recommendations call for enhancing security and accountability around these sources until replacements come to market, which for certain applications could take a decade or more.”
Categorizing Radioactive Sources by Risk
The International Atomic Energy Agency (IAEA) categorization system used by NRC places radioactive materials into five categories based on risk to human health. Category 1 materials have the highest potential to immediately harm human health, leading to the death or permanent injury of individuals who are exposed. Most commercial applications fall into Categories 1 – 3. The report says the current categorization system fails to provide an adequate level of protection to society because it does not take into account the long-term health risks of radiation exposure — or the severe societal and economic impacts of these materials’ use in a dirty bomb — but instead focuses only on the immediate consequences of exposure. Only Category 1 and Category 2 materials are currently subject to enhanced security measures and tracked by the NRC.
IAEA and NRC should reframe categorization to reflect the potential health, economic, and social impacts of these materials and to describe their overall risk more holistically. The NRC should also start tracking Category 3 sources to increase accountability and better enable informed security decisions, says the report.
- The National Nuclear Security Administration (NNSA) should prioritize funding for research and development projects that aim to develop alternatives where there are currently no acceptable nonradioisotopic technologies.
- NNSA should engage with federal partners such as the U.S. Department of Health and Human Services, the National Science Foundation (NSF), and the Food and Drug Administration to support equivalency studies for researchers who are considering replacing their cesium or cobalt research irradiators with alternative technologies.
- NNSA should engage with other offices within the U.S. Department of Energy, NSF, and professional societies to support equivalency studies for oil and gas well logging and industrial radiography service providers that are considering replacing their radioactive sources and adopting an alternative technology.
- The National Institute of Standards and Technology should engage immediately with the research community as well as federal, industry, and international partners to initiate research on alternatives to cesium chloride for calibration applications, to prepare for the possible future elimination of its use.
The report also contains a detailed table outlining the committee’s findings about available alternatives, replacement challenges, adoption trends, and promising areas of research and development for each radioactive source.
Replacement in Low- and Middle-Income Countries
The report says efforts by the U.S. government and other national and international organizations to reduce high-activity radioactive sources in low- and middle-income countries should be driven by the local resources, infrastructure, and needs. Efforts to replace radiation cancer therapies in low- and middle-income countries has sometimes had unintended negative effects on patient care, for example, if replacements require training for medical professionals that is unavailable or resources like electricity that are not always reliable. In situations in which local resources and infrastructure cannot support alternatives, the report says, efforts should instead focus on enhancing security and assisting with infrastructure building.
“This assistance could represent a major contribution to international efforts and specifically provide benefits to low- and middle-income nations,” added Kroc.
The study — undertaken by the Committee on Radioactive Sources: Applications and Alternative Technologies — was sponsored by the Sandia National Laboratories and the National Nuclear Security Administration. The National Academies of Sciences, Engineering, and Medicine are private, nonprofit institutions that provide independent, objective analysis and advice to the nation to solve complex problems and inform public policy decisions related to science, technology, and medicine. They operate under an 1863 congressional charter to the National Academy of Sciences, signed by President Lincoln.