The VVER-1000 is a type of pressurized water reactor (PWR) designed in the former Soviet Union. It has a thermal power output of 3,200 megawatts and is commonly used for electricity generation. The reactor uses enriched uranium fuel and features a double containment structure for safety. This reactor design is known for its reliability and efficiency, making it a popular choice in several countries, including Russia, Ukraine, and Hungary. The VVER-1000 has undergone various upgrades over the years to enhance its safety systems and operational performance.