"A likely remnant of a binary neutron-star merger or a neutron-star black-hole merger is a black hole surrounded by a differentially rotating disk of neutron-star debris. Besides being the favored candidate system for the central engine of a short gamma-ray burst, it is generally speculated that during the first few hundreds of milliseconds after its formation the disk could release massive outflows which, if they are sufficiently neutron-rich, could be a relevant contributor to the repertoire of r-process elements in the universe. Unfortunately, modeling the black-hole torus system is very challenging, mainly on account of the combined computational difficulties associated with multidimensional neutrino transport and turbulent angular momentum transport. In the talk, I will first present a radiation-magnetohydrodynamics code including energy-dependent, multidimensional two-moment neutrino transport which was recently developed to model the aforementioned systems. Afterwards, I will show and discuss the essential results we obtained for our models of viscous and magnetized black-hole torus systems."