On October 8, 1996 the plant was under 240 MW electrical power operation with two working turbogenerators. At 7 am one of the turbogenerators was disconnected from the grid and tripped by the control and protection system. Then, in order to maintain the parameters of primary and secondary circuits, the reactor power was decreased by personnel from 240 to 0 MWe. The previous investigation revealed that the cause of generator disconnection was a short circuit at the high-voltage line connecting the NPP with the national grid. The deviation caused neither on-site nor off-site radiation impact. Justification of rating: As full safety functions were available, the event is rated at level "0" per User's manual Part III.