  We investigate various aspects of the integrability of the vertex models
associated to the $D_n^2$ affine Lie algebra with open boundaries. We first
study the solutions of the corresponding reflection equation compatible with
the minimal symmetry of this system. We find three classes of general
solutions, one diagonal solution and two non-diagonal families with a free
parameter. Next we perform the Bethe ansatz analysis for some of the associated
open $D_2^2$ spin chains and we identify the boundary having quantum group
invariance. We also discuss a new $D_2^2$ $R$-matrix.
