Single crystal tungsten samples with orientation (110) were irradiated in the Materials Irradiation Experiment with normal incidence 30 keV He+ at 900 aC. Samples were mechanically polished and then electropolished with a KOH solution before irradiation to 3×1017 to 6×1018 He+/cm2. With increasing fluence sample surface pore size increased from ~20 nm to more than 100 nm. Mass loss also increased with fluence to a maximum of 15 g/m2 lost for the highest fluence sample.