Radiation detectionSafe, Fast Radionuclide Detection

In the event of a radiological release, such as from an improvised nuclear device, immediately assessing the threat to public safety would be critical. Rapid detection of radioactive materials can save lives, reduce the environmental impact of such an event and save taxpayer dollars. Current hand-held detection methods, however, are unreliable at detecting very low levels of alpha radiation from actinides, such as uranium, due to environmental influences.

INL researcher Dr. Cathy Riddle is a radiochemist who also enjoys keeping up with medical journals. About two years ago, she realized that the colorimetric tests used to identify drugs in the human body would be an ideal approach to take for assessing radiological contamination in the environment. These simple tests rapidly change color to clearly indicate the presence of the material in question, and they do not require technical expertise to perform them. Riddle reached out to her colleague, Dr. Rick Demmer, an expert in radiological incident cleanup, to share her idea. Together, they started to tackle the problem with the aid of INL’s laboratory-directed research and development (LDRD) seed program, created to give researchers like Riddle a way to pursue innovative technologies.

INL says that the team began testing different agents and quickly found combinations that worked but weren’t visually striking enough to be useful. They continued evaluating compounds and refining the process to make it more effective and easier to use. Two years later, Riddle and her group are developing two applications of the new CoDeAc (colorimetric detection of actinides; pronounced “Kodiak”) technology. The development process is going much more quickly than she thought it would. “You can have a thousand failed experiments, but rarely do you get home runs out of the gate,” she said.

·  One of the CoDeAc applications would allow first responders to take a sample of a liquid such as water and add a few drops of the indicator solution or use an indicator test strip (the kit includes a filter to remove particulates that would obscure the results). The solution can detect uranium concentrations as low as 24 parts per billion (ppb) by turning yellow. If concentrations are higher than 2 parts per million (ppm), the solution turns purple, giving a simple visual indication of the severity of contamination. Plutonium is also detected at parts per million levels and is indicated when the solution turns bright pink.

·  The same color-coded system applies to the second application, which is in the form of wipes that can be applied to any surface, with the color again indicating level of contamination.

The goal of CoDeAc’s simple design is developing detection kits that can be used to supplement municipal emergency preparedness programs, representing an important expansion of first responder and forensic examination capabilities. The basic hazard kits currently used to detect unknown substances aren’t capable of detecting radionuclides.

Applications and Additional Development Opportunities
One of the most persistent challenges of a governmental response to a radiation incident is how to keep the public safe without overreacting. Evacuating a wider area than necessary can do more harm than good because of disruption to medical and social welfare facilities. In such an event, CoDeAc could be used to quickly identify and narrow down geographic areas where actinide contamination exists, reducing the impact of the incident on the population and easing the logistics of actions such as evacuation and cleanup efforts.

In addition to helping first responders quickly assess public health and safety risks, the CoDeAc system has the potential to be used in other applications where radionuclide contamination is a possibility. For example, the CoDeAc coated wipes could be used regularly for facility maintenance checks and to aid radiation control personnel in nuclear facilities, and at testing or storage sites for radioactive materials.

As the CoDeAc technology matures, it has the potential to become even more effective through continuing refinement. The current system is unable to distinguish between the different isotopes of uranium or plutonium and is a go/no go scoping test. Riddle and Demmer are working to expand CoDeAc’s capabilities to include a broader range of actinides in the future. Additional government groups or private organizations may have interest in adapting CoDeAc technology for their own needs, such as the ability to detect select radionuclides and other kinds of water contaminants.

Owing to the success of the CoDeAc solution, it was named one of the top 15 new innovations of 2019 by Analytical Scientist Magazine and placed eighth overall in international competition for this award.

CoDeAc is an important example of the innovative ideas and technology INL researchers are working on every day at the lab and as Riddle puts it, “Making the world a better place is what we do here, all of us, every day!”