Last Thursday, the Balakovo nuclear plant's unit No.1 was shut down by the reactor's automatic safety system. The plant's chief engineer Viktor Ignatov said this was done by mistake. A technical inspection has revealed a deficiency in the control panel's feed line cables. The works to eliminate the malfunction and change the electrical cables are underway. No defects of the equipment, radiation background deterioration and violation of terms of safe exploitation have been detected. In accordance with the international nuclear plant performance scale, this breakage is safety-proof and can be rated at the zero level.