[8]: 36  The discovery of the neutron by the British physicist James Chadwick further provided promising expansion of the LPTI's program, with the operation of the first cyclotron to energies of over 1 MeV, and the first "splitting" of the atomic nucleus by John Cockcroft and Ernest Walton.

[9]: 20  The discovery excited the Russian physicists, and they began conducting their independent investigations on nuclear fission, mainly aiming towards power generation, as many were skeptical of the possibility of creating an atomic bomb anytime soon.

[10]: 25  Early efforts were led by Yakov Frenkel (a physicist specialised on condensed matter), who did the first theoretical calculations on continuum mechanics directly relating the kinematics of binding energy in fission process in 1940.

[9]: 99  Georgy Flyorov's and Lev Rusinov's collaborative work on thermal reactions concluded that 3–1 neutrons were emitted per fission only days after similar conclusions had been reached by the team of Frédéric Joliot-Curie.

[9]: 63 [11]: 200 After a strong lobbying of Russian scientists, the Soviet government initially set up a commission that was to address the "uranium problem" and investigate the possibility of chain reaction and isotope separation.

[12]: 33  The Uranium Problem Commission was ineffective because the German invasion of Soviet Union eventually limited the focus on research, as Russia became engaged in a bloody conflict along the Eastern Front for the next four years.

[15]: xx In 1940–42, Georgy Flyorov, a Russian physicist serving as an officer in the Soviet Air Force, noted that despite progress in other areas of physics, the German, British, and American scientists had ceased publishing papers on nuclear science.

[16]: 230  The dispersal of Soviet scientists had sent Abram Ioffe's Radium Institute from Leningrad to Kazan; and the wartime research program put the "uranium bomb" programme third, after radar and anti-mine protection for ships.

[17] In April 1942, Flyorov directed two classified letters to Stalin, warning him of the consequences of the development of atomic weapons: "the results will be so overriding [that] it won't be necessary to determine who is to blame for the fact that this work has been neglected in our country.

[16]: 230  Kurchatov was chosen in late 1942 as the technical director of the Soviet bomb program; he was awed by the magnitude of the task but was by no means convinced of its utility against the demands of the front.

[15]: xx  In late 1942, the State Defense Committee officially delegated the program to the Soviet Army, with major wartime logistical efforts later being supervised by Lavrentiy Beria, the head of NKVD.

[13]: 114–115 In 1945, the Arzamas 16 site, near Moscow, was established under Yakov Zel'dovich and Yuli Khariton who performed calculations on nuclear combustion theory, alongside Isaak Pomeranchuk.

[20]: 2–5  On 9 April 1946, the Council of Ministers created KB–11 ('Design Bureau-11') that worked towards mapping the first nuclear weapon design, primarily based on the American approach and detonated with weapon-grade plutonium.

They found him first-class administrator who could carry a job through to completion...The new Committee, under Beria, retained Georgii Malenkov and added Nikolai Voznesensky and Boris Vannikov, People's Commissar for Armament.

[26]: 289–290  Knowledge and further technical information that were passed by the American Theodore Hall, a theoretical physicist, and Klaus Fuchs had a significant impact on the direction of Russian development of nuclear weapons.

[31][32][full citation needed] Alexei Kojevnikov has estimated that the primary way in which the espionage may have sped up the Soviet project was that it allowed Khariton to avoid dangerous tests to determine the size of the critical mass.

This change was noted by the Russian translators, and alerted the Soviet Union to the problem (which had meant that reactor-bred plutonium could not be used in a simple gun-type bomb like the proposed Thin Man).

By 1951 Teller accepted the fact that the "classical super" scheme wasn't feasible, following results obtained by various researchers (including Stanislaw Ulam) and calculations performed by John von Neumann in late 1950.

[36] The third idea used the radiation wave of a fission bomb, not simply heat and compression, to ignite the fusion reaction, and paralleled the discovery made by Ulam and Teller.

The first Soviet uranium processing plant was established as the Leninabad Mining and Chemical Combine in Chkalovsk (present-day Buston, Ghafurov District), Tajikistan, and new production sites identified in relative proximity.

Domestic production was still insufficient when the Soviet F-1 reactor, which began operation in December 1946, was fueled using uranium confiscated from the remains of the German atomic bomb project.

In 1945, the Uranium enrichment through electromagnetic method under Lev Artsimovich also failed due to USSR's inability to build the parallel American Oak Ridge site and the limited power grid system could not produce the electricity for their program.

: 24–25 [58] Many of the nuclear devices left behind radioactive isotopes which have contaminated air, water and soil in the areas immediately surrounding, downwind and downstream of the blast site.

[57]: 6  The billions of radioactive particles released into the air exposed countless people to extremely mutagenic and carcinogenic materials, resulting in a myriad of deleterious genetic maladies and deformities.

Water contamination due to improper disposal of spent uranium and decay of sunken nuclear-powered submarines is a major problem in the Kola Peninsula in northwest Russia.

Although the Russian government states that the radioactive power cores are stable, various scientists have come forth with serious concerns about the 32,000 spent nuclear fuel elements that remain in the sunken vessels.

[60]: A166  There have been no major incidents other than the explosion and sinking of a nuclear-powered submarine in August 2000, but many international scientists are still uneasy at the prospect of the hulls eroding, releasing uranium into the sea and causing considerable contamination.

[60]: A165  Half a century later, in the 1990s, there are still hundreds of millions of curies of waste in the Lake, and at points contamination has been so severe that a mere half-hour of exposure to certain regions would deliver a dose of radiation sufficient to kill 50% of humans.

Public awareness of the past and present dangers, as well as the Russian government's investment in current cleanup efforts, are likely dampened by the lack of media attention STS and other sites have gotten in comparison to isolated nuclear incidents such as Hiroshima, Nagasaki, Chernobyl and Three-Mile Island.

[60]: A167  Although the bill stipulates that the revenue go towards decontaminating other test sites such as Semipalatinsk and the Kola Peninsula, experts doubt whether this will actually happen given the current political and economic climate in Russia.