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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.
Nisy E. Ipe
Nuclear Technology | Volume 168 | Number 2 | November 2009 | Pages 559-563
Shielding Materials | Special Issue on the 11th International Conference on Radiation Shielding and the 15th Topical Meeting of the Radiation Protection and Shielding Division (Part 2) / Radiation Protection | doi.org/10.13182/NT09-A9243
Articles are hosted by Taylor and Francis Online.
A typical particle therapy facility consists of an injector, a cyclotron or a synchrotron, a high-energy transport beam line, several treatment rooms including fixed-beam and gantry rooms, and even a research area. During the operation of these facilities, radiation is produced with neutrons being the dominant component outside the shielding. These facilities have large amounts of shielding with concrete thicknesses ranging up to [approximately]5 m or more. Space required for shielding can be minimized by using composite shielding or high-density material such as Ledite® (manufactured by Atomic International, Frederick, Pennsylvania). Transmission data for radiation from protons and carbon ions incident on tissue targets with energies in the therapeutic energy range of interest were derived using the Monte Carlo code FLUKA for three different compositions of Ledite. Use of Ledite® or composite shielding results in space savings when compared to concrete.