In 1938, he enrolled at the Moscow State University to study physics before leading a Komsomol platoon from 1941, building defences against Nazi Germany in Roslavl, Smolensk Oblast.

Ventsel, his dissertation supervisor, recommended that he go to the Institute of Chemical Physics as an assistant in Yakov Zeldovich's laboratory, part of the Soviet atomic bomb project.

[1][2][3] He was transferred to the closed city of Sarov, Nizhny Novgorod to KB-11 ('Design Bureau-11', also known as Arzamas-16 or the 'Installation'), the new centre of Soviet nuclear weapons design.

After the test of the first Soviet nuclear weapon in 1949, the RDS-1, he received the first of his national awards, the Order of Lenin and the Stalin Prize, for his contribution.

[1][4] Soviet authorities instigated a second weapons design installation at Chelyabinsk-70 (now Snezhinsk) in 1955, NII-1011 (Scientific Research Institute-1011), with Zababakhin as head of the theoretical department and deputy supervisor.

Concerned that the fallout would eventually kill thousands of people unnecessarily, he appealed first to Yulii Khariton (in charge of Soviet weapons design, who thought the appeal was invidious and divisive considering poor relations between the groups), then to premier Nikita Khrushchev (who said he felt ill), then to Efim Slavsky [ru], minister of medium machine building (who initially supported him).

[6] He performed experiments in the usage of nuclear charges for civilian enterprises with Boris Litvinov such as extinguishing gas flares and ore and fossil fuel production.