  The exact solvability of several nuclear models with non-degenerate
single-particle energies is outlined and leads to a generalization of
integrable Richardson-Gaudin models, like the $su(2)$-based fermion pairing, to
any simple Lie algebra. As an example, the $so(5)\sim sp(4)$ model of T=1
pairing is discussed and illustrated for the case of $^{64}$Ge with
non-degenerate single-particle energies.
