Nucleon Spin Structure and Large p_T Processes at pp Colliders

QCD motivated polarized parton distributions, evolved directly in $x$-space, are used to predict rates for prompt photon production at RHIC centre of mass energies. Various scenarios for the polarized gluon distributions are considered and compared, and the possibility of using large $p_T$ processes in polarized $pp$ collision experiments to choose between them is analyzed.