Polysulfone scintillation proximity membranes of a double-layered structure were prepared with Cerium Activated Yttrium Silicate (CAYS), impregnated in a membrane structure. Using the prepared membranes, the radioactivity of an area contaminated by radionuclides can be monitored without any scintillation cocktail. The membrane were formed through two separate casting and coagulation processes. The transparent and dense support layer was obtained by solidifying a polysulfone-methylene chloride binary solution through vacuum. CAYS-dispersed polymer solutions were cast over the top of solidified, transparent polymer films and coagulated by immersing into a coagulation bath, containing either water or isopropanol. The prepared membranes consist of double layers. The bottom layer is a dense, pure polymer film, and the top works as an active layer to detect a radioactive contamination. The membrane structures are significantly different depending on the nonsolvent type.