  SmFeAsO$_{1-x}$F$_x$ was irradiated in a fission reactor to a fast (E > 0.1
MeV) neutron fluence of 4x10^${21}$ m$^{-2}$. The introduced defects increase
the normal state resistivity due to a reduction in the mean free path of the
charge carriers. This leads to an enhancement of the upper critical field at
low temperatures. The critical current density within the grains, Jc, increases
upon irradiation. The second maximum in the field dependence of Jc disappears
and the critical current density becomes a monotonically decreasing function of
the applied magnetic field.
