Chernobyl disaster other undamaged reactors at the power station, with No. 3 continuing to produce electricity up into 2000. The accident motivated safety upgrades on all remaining Soviet-designed reactors in the RBMK (Chernobyl No. 4) family, of which eleven continued to power electric grids . The disaster began during a systems test on 26 April 1986 at reactor 4 of the Chernobyl plant near Pripyat and in proximity to the administrative border with Belarus and the Dnieper River. There was a sudden and unexpected power surge. When operators attempted an emergency shutdown, a much larger spike in power output occurred. This second
Effects of the Chernobyl disaster and slowed in 2005. The large increase in incidence of thyroid cancer happened amongst individuals who were adolescents and young children living during the time of the accident, and residing in the most contaminated areas of Belarus, the Russian Federation and Ukraine. High levels of radioactive iodine were released in the environment from the Chernobyl reactor after the accident, and accumulated in pastures which were eaten by cows. The milk was later consumed by children who already had an iodine deficient diet, therefore causing more of the radioactive iodine to be accumulated. Radioactive iodine has a short half-life, 8.02 days,