As a potential first-wall fusion reactor material, tungsten will be subjected to high radiation flux and extreme mechanical stress. We propose that under these conditions, coupled grain boundary (GB) motion, in some cases enhanced by interstitial loading, can lead to a radiation-damage healing mechanism, in which a large stress activates coupled GB motion, and the GB sweeps up the defects, such as voids and vacancies, as it passes through the material. The stress-induced mobility characteristics of a number of GBs in tungsten are examined to investigate the likelihood of this scenario.