Bryukhanov, assisted by chief engineer Nikolai Fomin instructed the operators to maintain and restore coolant supply, unaware that the reactor had already been destroyed.[1] The civil defense chief told him that radiation had reached the maximum reading of the military dosimeter of 200 roentgen per hour.[2] At 3:00 AM, Bryukhanov, contacted Vladimir V. Marin, the official in charge of nuclear matters of the Communist Party at his Moscow home to report the accident and assure officials that the situation was under control.[2][2] The radiation team reported that levels was only 13 microroentgen per hour, which was reassuring but incorrect.[2] At 5:15, Dyatlov staggered into the bunker with the operating reports showing power levels and coolant pressure charts.[2] Even though he had personally seen the damage to the reactor building, Bryukhanov continued to maintain that the reactor core was intact until well after daybreak.