Construction and start-up of the first Soviet uranium-grafite pile with self-developing chain reaction

A report on construction and start-up of a supercritical uranium-graphite pile in which self-developing chain reaction was observed for the first time in the Soviet Union on December 25, 1946 is published in the scientific periodical literature for the first time. A short review of works performed from Jule 1943 to December 1946 is given. The main theoretical and experimental preconditions for building the uranium-graphite pile are considered. Problems of the pile control and radiation protection are discussed. The main stages of the pile construction and start-up are described, as well as the results obtained during its operation