Development of radioactive microspheres for assessment of multiphase processes
W. S. Vieira1, J. C. S. Pinto2, R. T.Lopes2, M. N. de Souza3 1 Nuclear Engineering Institute - IEN/CNEN-RJ
Rua Hélio de Almeida, 75 Cidade Universitária Rio de Janeiro Brazil 21941-906
2 Federal University of Rio de Janeiro - COPPE/UFRJ
Centro de Tecnologia, Square G, Cidade Universitária, Rio de Janeiro Brazil 21941-972 email@example.com
3 Federal University of Rio de Janeiro - EQ/UFRJ
Centro de Tecnologia, Square E, Cidade Universitária, Rio de Janeiro Brazil 21941-972 firstname.lastname@example.org
The synthesis of polymeric spheres, combining organic and inorganic materials (hybrid spheres), has a considerable industrial interest. Although the use of these particles are growing in several areas, there are no reports about their applications on multiphase process optimization through the nuclear techniques known as CARPT (including CT or not). Therefore, this study was intended to take advantage on the versatility of this branch of research to solve the problem of preparing radioactive particles with the best properties for CARPT applications. First, a batch of La2O3-PMMA microspheres was prepared by suspension polymerization and the batch was characterized in laboratory to check its composition and morphology. The internal structure of the spheres was analyzed by x-ray microtomography (microCT), their external structure was evaluated by scanning electron microscopy (SEM) and the X-ray fluorescence (XRF) was employed for the chemical analysis. Next, the batch was irradiated in a neutron flux and the resultant Activity was measured using a 4π GeLi detector. The obtained spheres had a good spherical shape, suitable size and porosity, a specific mass with narrow range around 1300 kg/m3 and they could have an average Activity of 7.2 x 105 Bq immediately after being irradiated during 4h with a neutron flux of 1.7 x 1013 neutrons / m2.s. These results suggest that several types of microspheres can be successfully produced using polymerization systems for tracking solid or liquid phases in different multiphase systems, like the motion of catalysers in fluidized bed reactors.
Keywords: CARPT, CT, microCT, microsphere, PMMA.
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