Leach samples of SYNROC containing 10 wt% synthetic radwaste were irradiated with 3.5-MeV 4He+ ions and 250-keV 84Kr+ ions. The irradiations were carried out in an ultra-high vacuum chamber by clamping the samples in a holder such that the majority of the surface area of the samples could be exposed to the ion beams. The holder was designed to allow sample rotation with respect to the beam to ensure uniform damage production over the entire irradiated volume. The leach tests were conducted in deionized water at 90°C for various times. The comparison of the leach rates with those from the control samples shows that the SYNROC waste form retains its leach resistance even when exposed to large doses of displacement producing radiation.