The experimental industrial plant for hydrogen isotope separation on the basis of the Combined Electrolysis and Catalytic Exchange (CECE) process has been operating safely and reliably for 15 years in Petersburg Nuclear Physics Institute (PNPI). The plant has been designed to carry out the development of CECE process. In parallel with study of hydrogen isotope separation by CECE process the facility is used for processing heavy water wastes contaminated by tritium. The plant produces reactor quality heavy water and heavy water with reduced content of tritium less than 105 Bq/kg. The plant has been modified several times since its put into operation in 1995. This paper summarizes the CECE technology development and experience gained during the upgrade of facility, replacement of failed components and operation of the plant since its commissioning in 1995.