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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.
M. Yousif Alhaj, Alya Badawi, Hanaa H. Abou-Gabal, Nader M. A. Mohamed
Nuclear Technology | Volume 194 | Number 3 | June 2016 | Pages 314-323
Technical Paper | doi.org/10.13182/NT15-78
Articles are hosted by Taylor and Francis Online.
This research focuses on the utilization of thorium-plutonium fuel in pressurized water reactors (PWRs). The reference PWR selected in this research was the Westinghouse AP1000. Thorium-plutonium mixed-oxide (MOX) fuel assemblies partially replaced the uranium oxide fuel assemblies to reduce uranium demand. The cases studied contained 36, 48, 60, 72, and 84 thorium-plutonium MOX fuel assemblies, with the rest of the 193 fuel assemblies loaded with UO2 fuel. The core cycle length, the amount of plutonium incinerated, the amount of generated 233U in the spent fuel, and the conversion ratios were determined using MCNP6. For the different cases, safety parameters such as the power peaking factor and delayed neutron fraction (βeff) were evaluated. The study showed that using thorium-plutonium MOX can achieve good peaking power factors with delayed neutron fractions within the safety limits. Also a conversion factor of about 10% was achieved.