Experiences in surveillance of protective coatings at nuclear power plants

Durotuf STR type epoxy coatings of the localization towers in Units 1 and 2 of the Paks Nuclear Power Plant, Hungary, were investigated. Blisters and brownish stains on the coatings had been formed supposedly as the consequences of steady condensation and microbial infection. According to laboratory studies, different types of bacteria and fungi were identified both on the coatings, in boric acid solution and in the air samples taken from the absorption tower. Measures were taken to construct protective strainless steel walls and ceilings inside the tower. Epoflex resin is suggested to be applied as coating at Units 3 and 4 of the plant. (V.N.)