  The integrable XXX spin s quantum chain and the alternating $s^{1}$, $s^{2}$
($s^{1}-s^{2}={1\over 2}$) chain with boundaries are considered. The scattering
of their excitations with the boundaries via the Bethe ansatz method is
studied, and the exact boundary S matrices are computed in the limit $s, s^{1,
2} \to \infty$. Moreover, the connection of these models with the SU(2)
Principal Chiral, WZW and the RSOS models is discussed.
