A technical research study was developed for testing the decontamination using chemical gels. The study was realized for different type of samples, systems often encountered in the VVR-S nuclear research reactor from Magurele–Romania. The results obtained in the study have demonstrated that the decontamination gels could be an efficient way to reduce or to eliminate the surface contamination of buildings or equipment’s, minimizing the potential for spreading contamination during decommissioning activities.