Lead-alkali-silicate glass that is used for a shielding window of hot cells in nuclear technology has been irradiated by a Co-60 radioisotope source between. 0.998 and 35.939 kGray dose levels. Gamma rays can affect glass and change its several optical and solar parameters such as secondary internal heat transfer factor (q(i)), direct solar transmittance (tau (e)), solar factor (g) and shading coefficient via the absorbed dose. It is aimed to investigate the performance of the glass in terms of the shading coefficient, which is the most important parameter to view clearly inside of the hot cell. Furthermore, a comparative evaluation has been done with respect to the unexposed lead-alkali-silicate glass. Change in the shading coefficient with respect to absorbed dose is extremely important. (C) 2001 Elsevier Science B.V. All rights reserved.