ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
Latest Magazine Issues
Aug 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
September 2026
Nuclear Technology
Fusion Science and Technology
August 2026
Latest News
Undeclared uranium hitches a ride on cobalt exports from Congo, study says
Philippe (left) and Manzuk quantified the amount of uranium that has been exported from the DRC in cobalt shipments or left behind in the environment. (Photo: Joel Hallberg/UW–Madison)
Researchers at the University of Wisconsin–Madison and Princeton University have published a study in Nature Communications that calls attention to a blind spot in nuclear nonproliferation: The Democratic Republic of the Congo (DRC) has exported thousands of metric tons of uranium, and there is no accounting for where it has gone.
In partnership with Lighthouse Reports and the Financial Times, UW–Madison nuclear engineering professor and nuclear security expert Sébastien Philippe and Ryan Manzuk, a geologist and research fellow in Philippe’s group and at Princeton, conducted the study using countrywide mineralization and geochemical data.
Thomas B. Rezentes, Mark A. Prelas, Eric Lukosi, Matthew L. Watermann, Jack Crawford, and Richard H. Olsher
Nuclear Technology | Volume 187 | Number 1 | July 2014 | Pages 96-102
Technical Note | Radiation Transport and Protection | doi.org/10.13182/NT11-105
Articles are hosted by Taylor and Francis Online.
A computer-based investigative technique, using the Los Alamos Monte Carlo code MCNP5 version 1.51 (Radiation Safety Information Computational Center), was completed to assess the shallow dose equivalent (SDE) reported on the Landauer, Inc.,TM Luxel+ optically stimulated light (OSL) dosimeter. Experimental test irradiations were conducted on 18 OSL dosimeters through various controlled exposures to the source (10 mCi 90Sr). The reported SDE for each test irradiation was compared to the results for SDE calculated using MCNP5. All test irradiation experiments were conducted with the 90Sr source placed in direct contact with the dosimeter with slight placement changes across the dosimeter face. It was found that these slight adjustments caused vast differences in reported doses by Landauer. The SDE determined in a tissue matrix using MCNP5 was studied for two of the dosimeter badge geometries, and it was found that some qualitative agreement exists between the reported and simulated doses in contradiction with the experimental results. Further simulated analysis was not conducted because precise source-dosimeter geometries and the algorithm used by Landauer to analyze its Luxel+ OSL dosimeters were not known. These results indicate that a future study should be conducted with more rigorous simulated benchmarking to verify these results.