SERPENT/SUBCHANFLOW COUPLED BURNUP CALCULATIONS FOR VVER FUEL ASSEMBLIES Diego Ferraro, Manuel García, Uwe Imke, Ville Valtavirta, Riku Tuominen, Jaakko Leppänen and Víctor Sanchez-Espinoza EPJ Web Conf., 247 (2021) 04005 Published online: 22 February 2021 DOI: 10.1051/epjconf/202124704005