The water-water energetic reactor (WWER), or VVER (from Russian: Водо-водяной энергетический реактор; transliterates as Vodo-Vodyanoi Energetichesky Reaktor; Water-Water Power Reactor) is a series of pressurised water reactor designs originally developed in the Soviet Union, and now Russia, by OKB Gidropress.
Water-Water Energetic Reactor (VVER), atau WWER (dari Rusia: Водо-водяной энергетический реактор; transliterates sebagai Vodo-Vodyanoi Energetichesky Reaktor; air-air Reaktor) adalah serangkaian reaktor air bertekanan desain awalnya dikembangkan di Uni Soviet, dan sekarang Rusia, oleh OKB GIDROPRESS.