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.
Anne M. Adamczyk, John W. Norbury
Nuclear Technology | Volume 175 | Number 1 | July 2011 | Pages 216-227
Technical Paper | Special Issue on the 16th Biennial Topical Meeting of the Radiation Protection and Shielding Division / Radiation Transport and Protection | doi.org/10.13182/NT11-A12293
Articles are hosted by Taylor and Francis Online.
It is important that accurate estimates of crew exposure to radiation are obtained for future long-term space missions. Presently, several space radiation transport codes, all of which take as input particle interaction cross sections that describe the nuclear interactions between the particles and the shielding material, exist to predict the radiation environment. The space radiation transport code HZETRN uses the nuclear fragmentation model NUCFRG2 to calculate electromagnetic dissociation (EMD) cross sections. Currently, NUCFRG2 employs energy-independent branching ratios to calculate these cross sections. Using Weisskopf-Ewing (WE) theory to calculate branching ratios for compound nucleus reactions, however, is more advantageous than the method currently employed in NUCFRG2. The WE theory can calculate not only neutron and proton emission, as in the energy-independent branching ratio formalism used in NUCFRG2, but also deuteron, triton, helion, and alpha-particle emission. These particles can contribute significantly to total exposure estimates. In this work, photonuclear cross sections are calculated using WE theory and the energy-independent branching ratios used in NUCFRG2 and then compared to experimental data. It is found that the WE theory gives comparable but mainly better agreement with data than the energy-independent branching ratio. Furthermore, EMD cross sections for single neutron removal are calculated using WE theory and an energy-independent branching ratio used in NUCFRG2 and compared to experimental data.