  We discuss the properties of the previously constructed model of a
Schwarzschild black hole interior where the singularity is replaced by a
regular bounce, ultimately leading to a white hole. The model is semiclassical
in nature and uses as a source of gravity the effective stress-energy tensor
(SET) corresponding to vacuum polarization of quantum fields, and a minimum
spherical radius is a few orders of magnitude larger than the Planck length, so
that the effects of quantum gravity should be still negligible. We estimate the
other quantum contributions to the effective SET, caused by a nontrivial
topology of spatial sections and particle production from vacuum due to a
nonstationary gravitational field and show that these contributions are
negligibly small as compared to the SET due to vacuum polarization. The same is
shown for such classical phenomena as accretion of different kinds of matter to
the black hole and its further motion to the would-be singularity. Thus, in a
clear sense, our model of a semiclassical bounce instead of a Schwarzschild
singularity is stable under both quantum and classical perturbations.
