Modeling of a pyrolysis process for the elimination of epoxy resin from embedded nuclear fuels

Aziza Chairat (1, 2, 3) , Zhiya Duan (1, 2, 3) , Olivier Fiquet (2, 3) , Carine Ablitzer (2, 3) , Laurent Cassayre (1) , Hugues Vergnes (1) , Pascal Floquet (1) , Xavier Joulia (1)

1 LGC - Laboratoire de Génie Chimique
2 CEA Cadarache
3 CEA - Commissariat à l'énergie atomique et aux énergies alternatives

This paper presents the modeling of a bench-scale reactor for the pyrolysis of epoxy resin containing nuclear fuel samples. Strict operating conditions must be met to avoid nuclear fuel oxidation and the final hydrogen content in the residual char must be close to zero. By using the finite element method software, COMSOL Multiphysics®, transport phenomena and reaction kinetics can be combined to obtain a representative model of the reactor in terms of the temperature and the concentration distribution of the representative chemical species. The numerical results have been found consistent with the temperature measurements in the reactor. The model is also able to predict the distribution of permanent gases in the reactor over time. The variation in the composition and concentration of the gas near the fuel sample can then be monitored to control the oxygen potential. We have calculated the in-vessel transfers of a representative species of gases, hydrogen. The comparison of simulated and experimental values for hydrogen shows good agreement.

Mots clés: Pyrolysis; Multiphysics modeling; Epoxy resin; Nuclear fuel

Domaines: Génie chimique

Aziza Chairat, Zhiya Duan, Olivier Fiquet, Carine Ablitzer, Laurent Cassayre, et al.. Modeling of a pyrolysis process for the elimination of epoxy resin from embedded nuclear fuels. Computer Aided Chemical Engineering, 2017, 40, pp.343-348. ⟨10.1016/B978-0-444-63965-3.50059-3⟩. ⟨hal-01842285⟩