A radiation protection system to assess the internal contamination of workers during decontamination activities in an abounded fertilizer industry in the region of Attika, Greece, has been implemented. This system concerns, among other radionuclides, 226Ra. Because of the low 226Ra activities in urine, alpha spectrometry was used as the determination method after radiochemical separation. Radium was co precipitated with lead sulphate and purified using anion and cation exchange techniques. The source for the alpha spectrometric measurement was prepared by the electrodeposition of radium, from an aqueous/ethanol solution, onto stainless steel. The tracer used was 229Th. The chemical yield and the activity concentration were calculated via its daughter radionuclide 217At. Using the time-evolution formulas to calculate the 217At growth from its parent radionuclide 225Ra, a computer software was developed. This software was incorporated in a database, which automatically calculates and stores the results.