V.M. Vasylchenko,O. M. Masko, O.A. Purtov State Enterprise "State Scientific Engineering Center for Control Systems and Emergency Response" (SE "DNITS SCAR") Minenergouglya Ukraine, Kyiv UPDATING OF DECOMMISSIONING CONCEPT OF OPERATING NPP’S IN UKRAINE The paper contains a review of the main provisions of the updated Decommissioning Concept for the operating NPPs in Ukraine. The presented results of analysis are based on the consideration of six possible scenarios of the nuclear power complex development for the 15- and 20-year lifetime extension of the units, as well as the results of strategic planning and a long-term forecast of the operating NPPs decommissioning activity for two main decommissioning options, namely the deferred dismantling and immediate dismantling. Comparative cost estimations for the WWER-440 and WWER-1000 units decommissioning are given for the acting and the updated Concept. Keywords: updated NPP decommissioning concept, VVER-440, VVER-1000, long-term decommissioning forecast, cost estimates for decommissioning, life extension.