  We study the conductance $G$ of 2D Dirac semimetal nanowires at the presence
of disorder. For an even nanowire length $L$ determined by the number of unit
cells, we find non-integer values for $G$ that are independent of $L$ and
persist with weak disorder, indicated by the vanishing fluctuations of $G$. The
effect is created by a combination of the scattering effects at the
contacts(interface) between the leads and the nanowire, an energy gap present
in the nanowire for even $L$ and the topological properties of the 2D Dirac
semimetals. Unlike conventional materials the reduced $G$ due to the scattering
at the interface, is stabilized at non-integer values inside the nanowire,
leading to a topological phase for weak disorder. For strong disorder the
system leaves the topological phase and the fluctuations of $G$ are increased
as the system undergoes a transition/crossover toward the Anderson
localized(insulating) phase, via a non-standard disordered phase. We study the
scaling and the statistics of $G$ at these phases. In addition we have found
that the effect of robust non-integer $G$ disappears for odd $L$, which results
in integer $G$, determined by the number of open channels in the nanowire, due
to resonant scattering.
