A time-independent method which does not rely on a close-coupling approach has been developed for quantum mechanical reactive/dissociative collisions of collinear atom-diatom systems. The Schrodinger equation represented in hyperspherical coordinates is solved by means of a discrete variable representation. The results for a model H + HD system are compared with those obtained by the time-dependent wave-packet propagation calculation of Leforestier. The present method is powerful for the study of reactive collisions at energies above the dissociation threshold.