  We implement the KORAL code to perform two sets of very long general
relativistic radiation magnetohydrodynamic simulations of an axisymmetric
optically thin magnetized flow around a non-rotating black hole: one with a new
term in the electromagnetic field tensor due to the radiation pressure felt by
the plasma electrons on the comoving frame of the electron-proton plasma, and
one without. The source of the radiation is the accretion flow itself. Without
the new term, the system evolves to a standard accretion flow due to the
development of the magneto-rotational instability (MRI). With the new term,
however, the system eventually evolves to a magnetically arrested state (MAD)
in which a large scale jet-like magnetic field threads the black hole horizon.
Our results confirm the secular action of the Cosmic Battery in accretion flows
around astrophysical black holes.
