I don't have all the detailed facts but can helps with some of the overview (Google the details).
The Ukraine is a country south and west of Russia and was once part of the USSR before its dissolution. Pripyat is an abandoned city in northern Ukraine, near the border with Belarus. Named for the nearby Pripyat River, Pripyat was founded on 4 February 1970, the ninth nuclear city in the Soviet Union, for the nearby Chernobyl Nuclear Power Plant. In 1970 the city was founded and grew to 49,360 or so at the time of the disaster. After the disaster the city was forcibly evacuated and no one lives there now due to dangers of radiation. Nuclear power is the effort to use the radioactive decay of certain elements to turn it into electricity. This is done by using the radioactive decay to heat water into steam and the steam turns a generator turbine to make electricity. The power plant consists of the reactors where the heat transfer takes place, a source of water and a cooling area to allow the steam to return to liquid form. The electricity connects to an electric grid that distributes the power to consumers. Nuclear power is considered to be non-renewable but it does not create greenhouse gas emissions or other pollutants when it runs as planned. It does, however, create waste products that are highly radioactive that must be contained in a safe and remote place for a long time until it is safe (100's or 1000's or years).
Chernobyl has four reactors each capable of producing 1000MW. It employed 600 employees at the time but I am not sure if that is the actual total. On April 26, 1986 Reactor 4 experienced a sudden power surge during a systems test resulting in explosions and a fire. This allowed a release of radioactive gas and dust that spread widely. Many people died during and following the explosions and containment. It is thought that the political and economic costs of Chernobyl contributed to the fall of the Soviet Union. It caused the nuclear power industry to undergo safety inspections and many were retired. The environmental impacts in the areas around the incident are significant.
This from the NRC: "The majority of the five million residents living in contaminated areas, however, received very small radiation doses comparable to natural background levels (0.1 rem per year). (UNSCEAR 2008, pg. 124-25) Today the available evidence does not strongly connect the accident to radiation-induced increases of leukemia or solid cancer, other than thyroid cancer. Many children and adolescents in the area in 1986 drank milk contaminated with radioactive iodine, which delivered substantial doses to their thyroid glands. To date, about 6,000 thyroid cancer cases have been detected among these children. Ninety-nine percent of these children were successfully treated; 15 children and adolescents in the three countries died from thyroid cancer by 2005. The available evidence does not show any effect on the number of adverse pregnancy outcomes, delivery complications, stillbirths or overall health of children among the families living in the most contaminated areas. (UNSCEAR 2008, pg. 65) "
Chernobyl: Consequences of the Catastrophe for People and the Environment was published by the New York Academy of Sciences. It is authored by three noted scientists: Russian biologist Dr. Alexey Yablokov, former environmental advisor to the Russian president; Dr. Alexey Nesterenko, a biologist and ecologist in Belarus; and Dr.Vassili Nesterenko, a physicist and at the time of the accident director of the Institute of Nuclear Energy of the National Academy of Sciences of Belarus. Its editor is Dr. Janette Sherman, a physician and toxicologist long involved in studying the health impacts of radioactivity. The book is solidly based — on health data, radiological surveys and scientific reports — some 5,000 in all. It concludes that based on records now available, some 985,000 people died, mainly of cancer, as a result of the Chernobyl accident. That is between when the accident occurred in 1986 and 2004. More deaths, it projects, will follow.
