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[Time Stamp: 00:05] As the DOE report states, the entire accident occurred in a period of only about forty seconds.
[Time Stamp: 00:11] At the beginning, any perturbation in the system which increased void formation, even slightly, could have led to a major power excursion.
[Time Stamp: 00:19] At any time, during the slow power build-up, up until the power began to rise rapidly, system changes which reduced void formation could have prevented the accident.
[Time Stamp: 00:31] Once the power began to rise rapidly, there was nothing that could have been done to stop it.
[Time Stamp: 00:39] This scene was taken from a helicopter approaching Chernobyl, the morning of April 28th, 1986.
[Time Stamp: 01:08] Even though it is almost impossible to burn graphite, the Soviets reported that they estimated about 10% of the core graphite burned.
[Time Stamp: 01:19] This was due to the high temperature resulting from the accident, and was not a cause of the accident.
[Time Stamp: 01:51] The initial power excursion over-pressurized the vault and blew off the 1000 ton head.
[Time Stamp: 01:57] This caused a second and much larger excursion and energy release two or three seconds later.
[Time Stamp: 02:04] The resulting energy released by the fuel failure, the fuel-coolant interaction, and the release of the stored energy of the reactor completed the destruction of Chernobyl Unit 4