  We present a simple scheme for taking into account the resonant continuum
coupling in the Relativistic Mean Field- BCS (RMF-BCS) calculations. In this
scheme, applied before in non-relativistic calculations, the effect of the
resonant continuum on pairing correlations is introduced through the scattering
wave functions located in the region of the resonant states. These states are
found by solving the relativistic mean field equations with scattering-type
boundary conditions for continuum spectrum. The calculations are done for the
neutron-rich Zr isotopes. It is shown that the sudden increase of the neutron
radii close to the neutron drip line, the so-called giant halo, is determined
by a few resonant states close to the continuum threshold.
