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 tended to be longer-lived than those released by the detonation of atomic bombs. According to a 2009 United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the Chernobyl accident had by 2005 caused 61,200 man-Sv of radiation exposure to recovery workers and evacuees, 125,000 man-Sv to the populace of the Ukraine, Belarus, and Russia, and a dose to most of the more distant European countries amounting to 115,000 man-Sv. The same report estimated a further 25% more exposure would be received from residual radiosotopes after 2005. The total global collective dose from Chernobyl was earlier estimated by UNSCEAR