Nuclear Power Plant Meltdown
The accident at the Chernobyl Nuclear Power Plant in Ukrainian produced a plume of radioactive debris that drifted over parts of the western USSR, Eastern Europe, and Scandinavia. The accident, which occurred on April 26, 1986, was the worst nuclear power accident in history. Large areas of the Ukrainian, Belorussian, and Russian republics of the USSR were contaminated, resulting in the evacuation of roughly 200,000 people. The accident raised concerns about the safety of the Soviet nuclear power industry, slowing its expansion for a number of years, while forcing the Soviet government to become less secretive. The Chernobyl' Nuclear Power Plant was one of the largest in the USSR. It was located just outside of the town of Pripyat', about 18 km northwest of the town of Chernobyl'. The plant was only 16 km from the border between the Ukrainian and Belorussian republics and roughly 110 km north of Kiev, the capital and largest city of Ukraine. Construction of the plant began in the 1970s, with reactor No. 1 commissioned in 1977, followed by No. 2 (1978), No. 3 (1981), and No. 4 (1983). Each reactor had an electricity-generating capacity of 1,000 megawatts, and the four together produced about 10 percent of Ukraine's electricity at the time of the accident. Two more reactors (No. 5 and No. 6, also capable of producing 1,000 megawatts each) were under construction at the time of the accident. On the morning of April 26, 1986, reactor No. 4 was operating at very low capacity (6 to 7 percent) during a planned shutdown. Plant personnel intended to monitor the performance of turbine generators, which supplied electric power for the plant's own operation, during a changeover from standard to a backup source of power. The reactor's design made it unstable at low power, and the operators were careless about safety precautions during the test. After a sudden power surge, two explosions destroyed the reactor core and