August 29 was the United Nations’ International Day against Nuclear Tests. On that day in 1949 the Soviet Union carried out its first nuclear bomb test, at 7 a.m. at the Semipalatinsk test site.

The plutonium bomb, manufactured in the closed town of Ozersk in the Chelyabinsk Region and code-named RDS-1, exploded with a force equal to 22,000 metric tons of TNT.

The preparations for this first surface nuclear test began long before the bomb was even completed and were conducted with great care. The bomb designers believed that only a test explosion could provide them with complete information on the efficiency and combat capacities of the nuclear charge, according to information in the public domain.

Hundreds of thousands people were involved in building and testing the Soviet Union’s first nuclear bomb. Design Bureau No. 11 was one of the lead agencies on the project. It had been set up in 1946 specially to develop nuclear weapons. Famous physicists Igor Kurchatov and Yury Khariton were involved in the development of the Soviet nuclear program.