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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.
I. L. Rakhno, N. V. Mokhov, S. I. Striganov
Nuclear Technology | Volume 168 | Number 3 | December 2009 | Pages 689-693
Accelerators | Special Issue on the 11th International Conference on Radiation Shielding and the 15th Topical Meeting of the Radiation Protection and Shielding Division (PART 3) / Radiation Measurements and Instrumentation | doi.org/10.13182/NT09-A9291
Articles are hosted by Taylor and Francis Online.
A method to calculate residual activation of accelerator components is presented. A model for residual dose estimation for thick objects made of arbitrary composite materials for arbitrary irradiation and cooling times is employed in the study. A scaling procedure for applying the model to thin objects with linear dimensions less than a fraction of a nuclear interaction length is described. The scaling has been performed for various materials, and corresponding factors have been determined for objects of certain shapes (slab, solid, and hollow cylinder) that can serve as models for beam pipes, magnets, and collimators. Both contact residual dose and dose attenuation in the air outside irradiated objects are considered. A relation between continuous and pulsed irradiation is accounted for as well.