  Three dimensional topological superconductors with time reversal symmetry
(class DIII) are indexed by an integer $\nu$, the number of surface Majorana
cones, according to the free fermion classification. The superfluid B phase of
He$^3$ realizes the $\nu=1$ phase. Recently, it has been argued that this
classification is reduced in the presence of interactions to Z$_{16}$. This was
argued from the symmetry respecting surface topological orders of these states,
which provide a non-perturbative definition of the bulk topological phase.
Here, we verify this conclusion by focusing on the even index case, $\nu=2m$,
where a vortex condensation approach can be used to explicitly derive the
surface topological orders. We show a direct relation to the well known result
on one dimensional topological superconductors (class BDI), where interactions
reduce the free fermion classification from Z down to Z$_8$. Finally, we
discuss in detail the fermionic analog of Kramers time reversal symmetry, which
allows semions of some surface topological orders to transform as $T^2=\pm i$.
