Search This Blog

Saturday, May 20, 2023

Soviet atomic bomb project

From Wikipedia, the free encyclopedia
 
Soviet atomic bomb project
Soviet super test.jpg
The mushroom cloud from the
first air-dropped bomb test in 1951.
This picture is confused with RDS-27 and RDS-37 tests.
Operational scopeOperational R&D
Location
Planned byEmblema NKVD.svg NKVD, NKGB
Red star.svg GRU, MGB, PGU
Date1942–1949
Executed by Soviet Union
Outcome

The Soviet atomic bomb project was the classified research and development program that was authorized by Joseph Stalin in the Soviet Union to develop nuclear weapons during and after World War II.

Although the Soviet scientific community discussed the possibility of an atomic bomb throughout the 1930s, going as far as making a concrete proposal to develop such a weapon in 1940, the full-scale program was not initiated and prioritized until Operation Barbarossa.

Because of the conspicuous silence of the scientific publications on the subject of nuclear fission by German, American, and British scientists, Russian physicist Georgy Flyorov suspected that the Allied powers had secretly been developing a "superweapon" since 1939. Flyorov wrote a letter to Stalin urging him to start this program in 1942. Initial efforts were slowed due to the German invasion of the Soviet Union and remained largely composed of the intelligence gathering from the Soviet spy rings working in the U.S. Manhattan Project.

After Stalin learned of the atomic bombings of Hiroshima and Nagasaki, the program was pursued aggressively and accelerated through effective intelligence gathering about the German nuclear weapon project and the American Manhattan Project. The Soviet efforts also rounded up captured German scientists to join their program, and relied on knowledge passed by spies to Soviet intelligence agencies.

On 29 August 1949, the Soviet Union secretly conducted its first successful weapon test (First Lightning, based on the American "Fat Man" design) at the Semipalatinsk-21 in Kazakhstan. Stalin alongside Soviet political officials and scientists were elated at the successful test. A nuclear armed Soviet Union sent its rival Western neighbors, and particularly the United States into a state of unprecedented trepidation. From 1949 onwards the Soviet Union manufactured and tested nuclear weapons on a large scale. The nuclear capabilities these tests helped develop were crucial to projecting and maintaining its global status. In total, the Soviet Union conducted 715 nuclear weapon tests throughout the course of the Cold War. A nuclear-armed Soviet Union escalated the Cold War with the United States to the possibility of nuclear war and ushered in the doctrine of mutually assured destruction.

Early efforts

Background origins and roots

As early as 1910 in Russia, independent research was being conducted on radioactive elements by several Russian scientists. Despite the hardship faced by the Russian academy of sciences during the national revolution in 1917, followed by the violent civil war in 1922, Russian scientists had made remarkable efforts toward the advancement of physics research in the Soviet Union by the 1930s. Before the first revolution in 1905, the mineralogist Vladimir Vernadsky had made a number of public calls for a survey of Russia's uranium deposits but none were heeded. Such early efforts were independently and privately funded by various organizations until 1922 when the Radium Institute in Petrograd (now Saint Petersburg) opened and industrialized the research.

From the 1920s until the late 1930s, Russian physicists had been conducting joint research with their European counterparts on the advancement of atomic physics at the Cavendish Laboratory run by a New Zealand physicist, Ernest Rutherford, where Georgi Gamov and Pyotr Kapitsa had studied and researched.

Influential research towards the advancement of nuclear physics was guided by Abram Ioffe, who was the director at the Leningrad Physical-Technical Institute (LPTI), having sponsored various research programs at various technical schools in the Soviet Union. 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. Russian physicists began pushing the government, lobbying in the interest of the development of science in the Soviet Union, which had received little interest due to the upheavals created during the Russian revolution and the February Revolution. Earlier research was directed towards the medical and scientific exploration of radium; a supply of it was available as it could be retrieved from borehole water from the Ukhta oilfields.

In 1939, German chemist Otto Hahn reported his discovery of fission, achieved by the splitting of uranium with neutrons that produced the much lighter element barium. This eventually led to the realization among Russian scientists, and their American counterparts, that such reaction could have military significance. 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 possibility of creating an atomic bomb anytime soon. 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. 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.

World War II and accelerated feasibility

The 1942 Russian report on the feasibility of uranium titled: Disposition No. 2352: "On the organization of work on uranium.

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. 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. The Soviet atomic weapons program had no significance, and most work was unclassified as the papers were continuously published as public domain in academic journals.

Joseph Stalin, the Soviet leader, had mostly disregarded the atomic knowledge possessed by the Russian scientists as had most of the scientists working in the metallurgy and mining industry or serving in the Soviet Armed Forces technical branches during the World War II's eastern front in 1940–42.

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. Clearly, they each had active secret research programs. 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. Kurchatov had moved from Kazan to Murmansk to work on mines for the Soviet Navy.

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." The second letter, by Flyorov and Konstantin Petrzhak, highly emphasized the importance of a "uranium bomb": "it is essential to manufacture a uranium bomb without a delay."

Upon reading the Flyorov letters, Stalin immediately pulled Russian physicists from their respective military services and authorized an atomic bomb project, under engineering physicist Anatoly Alexandrov and nuclear physicist Igor V. Kurchatov. For this purpose, the Laboratory No. 2 near Moscow was established under Kurchatov. 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. Abram Ioffe had refused the post as he was too old, and recommended the young Kurchatov.

At the same time, Flyorov was moved to Dubna, where he established the Laboratory of Nuclear Reactions, focusing on synthetic elements and thermal reactions. 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.

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. Despite early and accelerated efforts, it was reported by historians that efforts on building a bomb using weapon-grade uranium seemed hopeless to Russian scientists. Igor Kurchatov had harboured doubts working towards the uranium bomb, but made progress on a bomb using weapon-grade plutonium after British data was provided by the NKVD.

The situation dramatically changed when the Soviet Union learned of the atomic bombings of Hiroshima and Nagasaki in 1945.

Immediately after the atomic bombing, the Soviet Politburo took control of the atomic bomb project by establishing a special committee to oversee the development of nuclear weapons as soon as possible. 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. From then on work on the program was carried out quickly, resulting in the first nuclear reactor near Moscow on 25 October 1946.

Organization and administration

The German assistance

From 1941 to 1946, the Soviet Union's Ministry of Foreign Affairs handled the logistics of the atomic bomb project, with Foreign Minister Vyacheslav Molotov controlling the direction of the program. However, Molotov proved to be a weak administrator, and the program stagnated. In contrast to American military administration in their atomic bomb project, the Russians' program was directed by political dignitaries such as Molotov, Lavrentiy Beria, Georgii Malenkov, and Mikhail Pervukhin—there were no military members.

After the atomic bombings of Hiroshima and Nagasaki, the program's leadership changed, when Stalin appointed Lavrentiy Beria on 22 August 1945. Beria is noted for leadership that helped the program to its final implementation.

Beria understood the necessary scope and dynamics of research. This man, who was the personification of evil to modern Russian history, also possessed the great energy and capacity to work. The scientists who met him could not fail to recognize his intelligence, his will power, and his purposefullness. They found him first-class administrator who could carry a job through to completion...

— Yulii Khariton, The First War of Physics: The Secret History of the Atom Bomb, 1939-1949[31]

The new Committee, under Beria, retained Georgii Malenkov and added Nikolai Voznesensky and Boris Vannikov, People's Commissar for Armament. Under the administration of Beria, the NKVD co-opted atomic spies of the Soviet Atomic Spy Ring into the American program, and infiltrated the German nuclear program whose nuclear scientists were later instrumental in attaining the feasibility of Soviet nuclear weapons.

Espionage

Soviet atomic ring

The 1945 sketch of circular shaped implosion-type passed by the American spies for the Soviet Union. This schematic was part of the development of RDS-1, test fired in Kazakhstan in 1949.

The nuclear and industrial espionages in the United States by American sympathisers of communism who were controlled by their rezident Russian officials in North America greatly aided the speed of the Soviet nuclear program from 1942–54. The willingness in sharing classified information to the Soviet Union by recruited American communist sympathizers increased when the Soviet Union faced possible defeat during the German invasion in World War II. The Russian intelligence network in the United Kingdom also played a vital role in setting up the spy rings in the United States when the Russian State Defense Committee approved resolution 2352 in September 1942.

For this purpose, the spy Harry Gold, controlled by Semyon Semyonov, was used for a wide range of espionage that included industrial espionage in the American chemical industry and obtaining sensitive atomic information that was handed over to him by the British physicist Klaus Fuchs. 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.

Leonid Kvasnikov, a Russian engineer turned KGB officer, was assigned for this special purpose and moved to New York City to coordinate such activities. Anatoli Yatzkov, another NKVD official in New York, was also involved in obtaining sensitive information gathered by Sergei Kournakov from Saville Sax.

The existence of Russian spies was exposed by the U.S. Army's secretive Venona project in 1943.

For example, Soviet work on methods of uranium isotope separation was altered when it was reported, to Kurchatov's surprise, that the Americans had opted for the Gaseous diffusion method. While research on other separation methods continued throughout the war years, the emphasis was placed on replicating U.S. success with gaseous diffusion. Another important breakthrough, attributed to intelligence, was the possibility of using plutonium instead of uranium in a fission weapon. Extraction of plutonium in the so-called "uranium pile" allowed bypassing of the difficult process of uranium separation altogether, something that Kurchatov had learned from intelligence from the Manhattan project.

Soviet intelligence management in the Manhattan Project

In 1945, the Soviet intelligence obtained rough blueprints of the first U.S. atomic device. Alexei Kojevnikov has estimated, based on newly released Soviet documents, 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: "tickling the dragon's tail", as it was called in the U.S., consumed a good deal of time and claimed at least two lives; see Harry Daghlian and Louis Slotin.

The published Smyth Report of 1945 on the Manhattan Project was translated into Russian, and the translators noted that a sentence on the effect of "poisoning" of Plutonium-239 in the first (lithograph) edition had been deleted from the next (Princeton) edition by Groves. 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).

One of the key pieces of information, which Soviet intelligence obtained from Fuchs, was a cross-section for D-T fusion. This data was available to top Soviet officials roughly three years before it was openly published in the Physical Review in 1949. However, this data was not forwarded to Vitaly Ginzburg or Andrei Sakharov until very late, practically months before publication. Initially both Ginzburg and Sakharov estimated such a cross-section to be similar to the D-D reaction. Once the actual cross-section become known to Ginzburg and Sakharov, the Sloika design become a priority, which resulted in a successful test in 1953.

In the 1990s, with the declassification of Soviet intelligence materials, which showed the extent and the type of the information obtained by the Soviets from US sources, a heated debate ensued in Russia and abroad as to the relative importance of espionage, as opposed to the Soviet scientists' own efforts, in the making of the Soviet bomb. The vast majority of scholars agree that whereas the Soviet atomic project was first and foremost a product of local expertise and scientific talent, it is clear that espionage efforts contributed to the project in various ways and most certainly shortened the time needed to develop the atomic bomb.

Comparing the timelines of H-bomb development, some researchers came to the conclusion that the Soviets had a gap in access to classified information regarding the H-bomb at least between late 1950 and some time in 1953. Earlier, e.g., in 1948, Fuchs gave the Soviets a detailed update of the classical super progress, including an idea to use lithium, but did not explain it was specifically lithium-6. 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.

Yet the research for the Soviet analogue of "classical super" continued until December 1953, when the researchers were reallocated to a new project working on what later became a true H-bomb design, based on radiation implosion. This remains an open topic for research, whether the Soviet intelligence was able to obtain any specific data on Teller-Ulam design in 1953 or early 1954. Yet, Soviet officials directed the scientists to work on a new scheme, and the entire process took less than two years, commencing around January 1954 and producing a successful test in November 1955. It also took just several months before the idea of radiation implosion was conceived, and there is no documented evidence claiming priority. It is also possible that Soviets were able to obtain a document lost by John Wheeler on a train in 1953, which reportedly contained key information about thermonuclear weapon design.

Initial thermonuclear designs

Early Russian design on thermonuclear device dated back to 1955.

Early ideas of the fusion bomb came from espionage and internal Soviet studies. Though the espionage did help Soviet studies, the early American H-bomb concepts had substantial flaws, so it may have confused, rather than assisted, the Soviet effort to achieve nuclear capability. The designers of early thermonuclear bombs envisioned using an atomic bomb as a trigger to provide the needed heat and compression to initiate the thermonuclear reaction in a layer of liquid deuterium between the fissile material and the surrounding chemical high explosive. The group would realize that a lack of sufficient heat and compression of the deuterium would result in an insignificant fusion of the deuterium fuel.

Andrei Sakharov's study group at FIAN in 1948 came up with a second concept in which adding a shell of natural, unenriched uranium around the deuterium would increase the deuterium concentration at the uranium-deuterium boundary and the overall yield of the device, because the natural uranium would capture neutrons and itself fission as part of the thermonuclear reaction. This idea of a layered fission-fusion-fission bomb led Sakharov to call it the sloika, or layered cake. It was also known as the RDS-6S, or Second Idea Bomb. This second bomb idea was not a fully evolved thermonuclear bomb in the contemporary sense, but a crucial step between pure fission bombs and the thermonuclear "supers". Due to the three-year lag in making the key breakthrough of radiation compression from the United States the Soviet Union's development efforts followed a different course of action. In the United States they decided to skip the single-stage fusion bomb and make a two-stage fusion bomb as their main effort. Unlike the Soviet Union, the analog RDS-7 advanced fission bomb was not further developed, and instead, the single-stage 400-kiloton RDS-6S was the Soviet's bomb of choice.

The RDS-6S Layer Cake design was detonated on 12 August 1953, in a test given the code name by the Allies of "Joe 4". The test produced a yield of 400 kilotons, about ten times more powerful than any previous Soviet test. Around this time the United States detonated its first super using radiation compression on 1 November 1952, code-named Mike. Though the Mike was about twenty times greater than the RDS-6S, it was not a design that was practical to use, unlike the RDS-6S.

Following the successful launching of the RDS-6S, Sakharov proposed an upgraded version called RDS-6SD. This bomb was proved to be faulty, and it was neither built nor tested. The Soviet team had been working on the RDS-6T concept, but it also proved to be a dead end.

In 1954, Sakharov worked on a third concept, a two-stage thermonuclear bomb. 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. Unlike the RDS-6S boosted bomb, which placed the fusion fuel inside the primary A-bomb trigger, the thermonuclear super placed the fusion fuel in a secondary structure a small distance from the A-bomb trigger, where it was compressed and ignited by the A-bomb's x-ray radiation. The KB-11 Scientific-Technical Council approved plans to proceed with the design on 24 December 1954. Technical specifications for the new bomb were completed on 3 February 1955, and it was designated the RDS-37.

The RDS-37 was successfully tested on 22 November 1955 with a yield of 1.6 megaton. The yield was almost a hundred times greater than the first Soviet atomic bomb six years before, showing that the Soviet Union could compete with the United States. and would even exceed them in time.

Logistical problems

The single largest problem during the early Soviet program was the procurement of raw uranium ore, as the Soviet Union had limited domestic sources at the beginning of their nuclear program. The era of domestic uranium mining can be dated exactly, to November 27, 1942, the date of a directive issued by the all-powerful wartime State Defense Committee. The first Soviet uranium mine was established in Taboshar, present-day Tajikistan, and was producing at an annual rate of a few tons of uranium concentrate by May 1943. Taboshar was the first of many officially secret Soviet closed cities related to uranium mining and production.

Demand from the experimental bomb project was far higher. The Americans, with the help of Belgian businessman Edgar Sengier in 1940, had already blocked access to known sources in Congo, South Africa, and Canada. In December 1944 Stalin took the uranium project away from Vyacheslav Molotov and gave to it to Lavrentiy Beria. 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. This posed a need for labor, a need that Beria would fill with forced labor: tens of thousands of Gulag prisoners were brought to work in the mines, the processing plants, and related construction.

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. This uranium had been mined in the Belgian Congo, and the ore in Belgium fell into the hands of the Germans after their invasion and occupation of Belgium in 1940. 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.

Further sources of uranium in the early years of the program were mines in East Germany (via the deceptively-named SAG Wismut), Czechoslovakia, Bulgaria, Romania (the Băița mine near Ștei) and Poland. Boris Pregel sold 0.23 tonnes of uranium oxide to the Soviet Union during the war, with the authorisation of the U.S. Government.

Eventually, large domestic sources were discovered in the Soviet Union (including those now in Kazakhstan).

The uranium for the Soviet nuclear weapons program came from mine production in the following countries,

Year USSR Germany Czechoslovakia Bulgaria Poland
1945 14.6 t



1946 50.0 t 15 t 18 t 26.6 t
1947 129.3 t 150 t 49.1 t 7.6 t 2.3 t
1948 182.5 t 321.2 t 103.2 t 18.2 t 9.3 t
1949 278.6 t 767.8 t 147.3 t 30.3 t 43.3 t
1950 416.9 t 1,224 t 281.4 t 70.9 t 63.6 t

Important nuclear tests

The Soviet program of nuclear weapons produces the stockpile (shown in black and white) reaching at its height in 1986 exceeding the United States stockpiles.

RDS-1

RDS-1, the first Soviet atomic test was internally code-named First Lightning (Первая молния, or Pervaya Molniya) August 29, 1949, and was code-named by the Americans as Joe 1. The design was very similar to the first US "Fat Man" plutonium bomb, using a TNT/hexogen implosion lens design.

RDS-2

On September 24, 1951, the 38.3 kiloton device RDS-2 was tested based on a tritium "boosted" uranium implosion device with a levitated core. This test was code named Joe 2 by the CIA.

RDS-3

RDS-3 was the third Soviet atomic bomb. On October 18, 1951, the 41.2 kiloton device was detonated - a boosted weapon using a composite construction of levitated plutonium core and a uranium-235 shell. Code named Joe 3 in the USA, this was the first Soviet air-dropped bomb test. Released at an altitude of 10 km, it detonated 400 meters above the ground.

RDS-4

RDS-4 represented a branch of research on small tactical weapons. It was a boosted fission device using plutonium in a "levitated" core design. The first test was an air drop on August 23, 1953, yielding 28 kilotons. In 1954, the bomb was also used during Snowball exercise in Totskoye, dropped by Tu-4 bomber on the simulated battlefield, in the presence of 40,000 infantry, tanks, and jet fighters. The RDS-4 comprised the warhead of the R-5M, the first medium-range ballistic missile in the world, which was tested with a live warhead for the first and only time on February 5, 1956

RDS-5

RDS-5 was a small plutonium based device, probably using a hollow core. Two different versions were made and tested.

RDS-6

RDS-6, the first Soviet test of a hydrogen bomb, took place on August 12, 1953, and was nicknamed Joe 4 by the Americans. It used a layer-cake design of fission and fusion fuels (uranium 235 and lithium-6 deuteride) and produced a yield of 400 kilotons. This yield was about ten times more powerful than any previous Soviet test. When developing higher level bombs, the Soviets proceeded with the RDS-6 as their main effort instead of the analog RDS-7 advanced fission bomb. This led to the third idea bomb which is the RDS-37.

RDS-9

A much lower-power version of the RDS-4 with a 3-10 kiloton yield, the RDS-9 was developed for the T-5 nuclear torpedo. A 3.5 kiloton underwater test was performed with the torpedo on September 21, 1955.

RDS-37

The first Soviet test of a "true" hydrogen bomb in the megaton range was conducted on November 22, 1955. It was dubbed RDS-37 by the Soviets. It was of the multi-staged, radiation implosion thermonuclear design called Sakharov's "Third Idea" in the USSR and the Teller–Ulam design in the USA.

Joe 1, Joe 4, and RDS-37 were all tested at the Semipalatinsk Test Site in Kazakhstan.

Tsar Bomba (RDS-220)

The Tsar Bomba (Царь-бомба) was the largest, most powerful thermonuclear weapon ever detonated. It was a three-stage hydrogen bomb with a yield of about 50 megatons. This is equivalent to ten times the amount of all the explosives used in World War II combined. It was detonated on October 30, 1961, in the Novaya Zemlya archipelago, and was capable of approximately 100 megatons, but was purposely reduced shortly before the launch. Although weaponized, it was not entered into service; it was simply a demonstrative testing of the capabilities of the Soviet Union's military technology at that time. The heat of the explosion was estimated to potentially inflict third degree burns at 100 km distance of clear air.

Chagan

Chagan was a shot in the Nuclear Explosions for the National Economy (also known as Project 7), the Soviet equivalent of the US Operation Plowshare to investigate peaceful uses of nuclear weapons. It was a subsurface detonation. It was fired on January 15, 1965. The site was a dry bed of the river Chagan at the edge of the Semipalatinsk Test Site, and was chosen such that the lip of the crater would dam the river during its high spring flow. The resultant crater had a diameter of 408 meters and was 100 meters deep. A major lake (10,000 m3) soon formed behind the 20–35 m high upraised lip, known as Chagan Lake or Balapan Lake.

The photo is sometimes confused with RDS-1 in literature.

Secret cities

The Radioaktivnost' warning sign left at the now-ruined and abandoned Laboratory B in Sungulʹ, ca. 2009.

During the Cold War, the Soviet Union created at least nine closed cities, known as Atomgrads, in which nuclear weapons-related research and development took place. After the dissolution of the Soviet Union, all of the cities changed their names (most of the original code-names were simply the oblast and a number). All are still legally "closed", though some have parts of them accessible to foreign visitors with special permits (Sarov, Snezhinsk, and Zheleznogorsk).

Cold War name Current name Established Primary function(s)
Arzamas-16 Sarov 1946 Weapons design and research, warhead assembly
Sverdlovsk-44 Novouralsk 1946 Uranium enrichment
Chelyabinsk-40 and later 65 Ozyorsk 1947 Plutonium production, component manufacturing
Sverdlovsk-45 Lesnoy 1947 Uranium enrichment, warhead assembly
Tomsk-7 Seversk 1949 Uranium enrichment, component manufacturing
Krasnoyarsk-26 Zheleznogorsk 1950 Plutonium production
Zlatoust-36 Tryokhgorny 1952 Warhead assembly
Penza-19 Zarechny 1955 Warhead assembly
Krasnoyarsk-45 Zelenogorsk 1956 Uranium enrichment
Chelyabinsk-70 Snezhinsk 1957 Weapons design and research

Environmental and public health effects

The former Soviet nuclear devices left behind large amounts of radioactive isotopes, which have contaminated air, water, and soil in the areas immediately surrounding them, enough to double the normal rate of 14C from the atmosphere, and due to the increase in biomass and necromass.

The Soviets started experimenting with nuclear technology in 1943 with very little regard of nuclear safety as there were no reports of accidents that were ever made public to learn from, and the public was kept in hidden about the radiation dangers. 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. According to the records that the Russian government released in 1991, the Soviet Union tested 969 nuclear devices between 1949 and 1990— the more nuclear testing than any nation in the planet. Soviet scientists conducted the tests with little regard for environmental and public health consequences. The detrimental effects that the toxic waste generated by weapons testing and processing of radioactive materials are still felt to this day. Even decades later, the risk of developing various types of cancer, especially that of the thyroid and the lungs, continues to be elevated far above national averages for people in affected areas. Iodine-131, a radioactive isotope that is a major byproduct of fission-based weapons, is retained in the thyroid gland, and so poisoning of this kind is commonplace in impacted populations.

The Soviets set off 214 nuclear devices in the open atmosphere between 1949 and 1962, the year the United Nations banned atmospheric tests worldwide. 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. The majority of these tests took place at the Semipalatinsk Test Site, or the Polygon, located in northeast of Kazakhstan. The testing at Semipalatinsk alone exposed hundreds of thousands of Kazakh citizens to the harmful effects, and the site continues to be one of the most highly irradiated places on the planet. When the earliest tests were being conducted, even the scientists had only a poor understanding of the medium-and long-term effects of radiation exposure— many did not notify each other of their work if they had serious accidents or expose of radiation. In fact, the Semipalatinsk was chosen as the primary site for open-air testing precisely because the Soviets were curious about the potential for lasting harm that their weapons held.

The ecosystem collapse of the receding Aral sea in Central Asia has left huge plains covered with salt and toxic chemicals from nuclear weapons testing, industrial projects, and pesticides and fertilizer runoff.
 
The 1996 level of Cesium-137 contamination over Ukraine after an unsafe operation led to a serious accident in 1986.

Contamination of air and soil due to atmospheric testing is only part of a wider issue. 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. 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. Although the submarines pose an environmental risk, they have yet to cause serious harm to public health. However, water contamination in the area of the Mayak test site, especially at Lake Karachay, is extreme, and has gotten to the point where radioactive byproducts have found their way into drinking water supplies. It has been an area of concern since the early 1950s, when the Soviets began disposing of tens of millions of cubic meters of radioactive waste by pumping it into the small lake. 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. Although the area immediately surrounding the lake is devoid of population, the lake has the potential to dry up in times of drought. Most significantly, in 1967, it dried up and winds carried radioactive dust over thousands of square kilometers, exposing at least 500,000 citizens to a range of health risks. To control dust, Soviet scientists piled concrete on top of the lake. Although this was effective in helping mediate the amount of dust, the weight of the concrete pushed radioactive materials into closer contact with standing underground groundwater.[61]: A166  It is difficult to gauge the overall health and environmental effects of the water contamination at Lake Karachay because figures on civilian exposure are unavailable, making it hard to show causation between elevated cancer rates and radioactive pollution specifically from the lake.

Contemporary efforts to manage radioactive contamination in the former Soviet Union are few and far between. 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. The domestic government's investment in cleanup measures seems to be driven by economic concerns rather than care for public health. The most significant political legislation in this area is a bill agreeing to turn the already contaminated former weapons complex Mayak into an international radioactive waste dump, accepting cash from other countries in exchange for taking their radioactive byproducts of nuclear industry. 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.

Friday, May 19, 2023

Tsar Bomba

From Wikipedia, the free encyclopedia
 
Tsar Bomba
Tsar bomba=eM.png
Ground-level view of detonation (source: Rosatom State Corporation Communications Department: Rosatom: 20-08-2020 public release)
TypeThermonuclear
Place of originSoviet Union
Production history
DesignerYulii Khariton, Andrei Sakharov, Viktor Adamsky, Yuri Babayev and Yuri Smirnov [ru], Yuri Trutnev, and Yakov Zeldovich
ManufacturerSoviet Union
No. built1 operational (2 "prototypes")
Specifications
Mass27,000 kg (60,000 lb)
Length8 m (26 ft)
Diameter2.1 m (6 ft 11 in)

Detonation
mechanism
Barometric sensor
Blast yield50–58 megatons of TNT (210–240 PJ)

Coordinates: 73°48′26″N 54°58′54″E

The Tsar Bomba (Russian: Царь-бо́мба) (code name: Ivan or Vanya), also known by the alphanumerical designation "AN602", was a thermonuclear aerial bomb, and the most powerful nuclear weapon ever created and tested. The Soviet physicist Andrei Sakharov oversaw the project at Arzamas-16, while the main work of design was by Sakharov, Viktor Adamsky, Yuri Babayev, Yuri Smirnov [ru], and Yuri Trutnev. The project was ordered by Nikita Khrushchev in July 1961 as part of the Soviet resumption of nuclear testing after the Test Ban Moratorium, with the detonation timed to coincide with the 22nd Congress of the Communist Party of the Soviet Union.

Tested on 30 October 1961, the test verified new design principles for high-yield thermonuclear charges, allowing, as its final report put it, the design of a nuclear device "of practically unlimited power". The bomb was dropped by parachute from a Tu-95V aircraft, and detonated autonomously 4,000 metres (13,000 ft) above the cape Sukhoy Nos of Severny Island, Novaya Zemlya, 15 km (9.3 mi) from Mityushikha Bay, north of the Matochkin Strait. The detonation was monitored by United States intelligence agencies, via a KC-135A aircraft (Operation SpeedLight) in the area at the time. A secret U.S. reconnaissance aircraft named "Speed Light Alpha" monitored the blast, coming close enough to have its antiradiation paint scorched.

The bhangmeter results and other data suggested the bomb yielded around 58 Mt (243 PJ), which was the accepted yield in technical literature until 1991, when Soviet scientists revealed that their instruments indicated a yield of 50 Mt (209 PJ). As they had the instrumental data and access to the test site, their yield figure has been accepted as more accurate. In theory, the bomb would have had a yield in excess of 100 Mt (418 PJ) if it had included the uranium-238 fusion tamper which featured in the design but was omitted in the test to reduce radioactive fallout. As only one bomb was built to completion, that capability has never been demonstrated. The remaining bomb casings are located at the Russian Atomic Weapon Museum in Sarov and the Museum of Nuclear Weapons, All-Russian Scientific Research Institute Of Technical Physics, in Snezhinsk.

Tsar Bomba was a modification of an earlier project, RN202, which used a ballistic case of the same size but a very different internal mechanism. A number of published books, even some authored by those involved in product development 602, contain inaccuracies that are replicated elsewhere, including wrongly identifying Tsar Bomba as RDS-202 or RN202.

Project goals

In the mid-1950s, the United States had an unconditional superiority over the USSR in nuclear weapons, although thermonuclear charges had already been created in the USSR at this time. Also, there were no effective means of delivering nuclear warheads to the US, both in the 1950s and in 1961. The USSR was not therefore able to muster a possible realistic retaliatory nuclear strike against the US.

Given the Soviet Union's actual strategic disadvantage in relation to America's nuclear weapons possessions, foreign policy and propaganda considerations during the leaderships of Georgy Malenkov and Nikita Khrushchev made a response to the perceived US nuclear blackmail imperative. The creation of the Tsar Bomba represented a bluff in order to maintain the concept of nuclear deterrence.

Also on June 23, 1960, the Resolution of the Council of Ministers of the USSR was issued on the creation of a super-heavy ballistic missile N-1 (GRAU index – 11A52) with a warhead weighing 75 tonnes (83 short tons). For a comparative assessment, the weight of the warhead tested in 1964 by the UR-500 ICBM was 14 tonnes (15 short tons).

The development of new designs of nuclear and thermonuclear ammunition requires testing. The operability of the device, its safety in emergency situations, and the calculated energy release during an explosion must be confirmed.

Name

The bomb was officially known as "product 602" (изделие 602) or "AN602", and codenamed "Ivan". The usage of different names can be a source of confusion. The Tsar Bomba, being a modification of the RN202, is sometimes mistakenly labelled as RDS-37, RDS-202 or PH202 (product 202). It has also been referred to as RDS-220 in a number of relatively recent western publications.

Unofficially, the bomb would later become known as "Tsar Bomba" and "Kuzka's mother" (Кузькина мать, Kuz'kina mat'). The name Tsar Bomba (loosely translated as Emperor of Bombs) comes from an allusion to two other Russian historical artifacts, the Tsar Cannon and the Tsar Bell, both of which were created as showpieces but whose large size made them impractical for actual use. The name "Tsar Bomba" does not seem to have been used for the weapon prior to the 1990s. The name "Kuzka's Mother" was inspired by the statement of Khrushchev to then US Vice President Richard Nixon: "We have funds at our disposal that will have dire consequences for you. We will show you Kuzka's mother!"

The Central Intelligence Agency (CIA) designated the test as "JOE 111", using their "JOE" counting scheme begun with RDS-1 in 1949.

Development

A Tsar Bomba-type casing on display at the Sarov atomic bomb museum, Sarov

The development of a super-powerful bomb began in 1956 and was carried out in two stages. At the first stage, from 1956 to 1958, it was "product 202", which was developed in the recently created NII-1011. The modern name of NII-1011 is the "Russian Federal Nuclear Center or the All-Russian Scientific Research Institute of Technical Physics" (RFNC-VNIITF). According to the official history of the institute, the order on the creation of a research institute in the system of the Ministry of Medium Machine Building was signed on April 5, 1955; work at the NII-1011 began a little later.

At the second stage of development, from 1960 to a successful test in 1961, the bomb was called "item 602" and was developed at KB-11 (VNIIEF), V. B. Adamsky was developing, and besides him, the physical scheme was developed by Andrei Sakharov, Yu. N. Babaev, Yu. N. Smirnov, Yu. A. Trutnev.

Product 202

After the successful test of the RDS-37, KB-11 employees (Sakharov, Zeldovich, and Dovidenko) performed a preliminary calculation and, on February 2, 1956, they handed over to N. I. Pavlov, a note with the parameters for charges of 150 Mt (628 PJ) and the possibility of increasing the power to 1 gigaton of TNT (4.2 EJ).

After the creation in 1955 of the second nuclear center – NII-1011, in 1956, by a resolution of the Council of Ministers, the center was assigned the task of developing an ultra-high-power charge, which was called "Project 202".

On March 12, 1956, a draft Joint Resolution of the Central Committee of the Communist Party of the Soviet Union (CPSU Central Committee) and the Council of Ministers of the Soviet Union on the preparation and testing of the 202 product was adopted. The project planned to develop a version of the RDS-37 with a capacity of 30 Mt (126 PJ). RDS-202 was designed with a maximum calculated power release of 50 Mt (209 PJ), with a diameter of 2.1 m (6 ft 11 in), a length of 8 m (26 ft), weighing 26 tonnes (29 short tons) with a parachute system and structurally coordinated with the Tu-95-202 carrier aircraft specially converted for its use. On June 6, 1956, the NII-1011 report described the RDS-202 thermonuclear device with a design power of up to 38 Mt (159 PJ) with the required task of 20–30 Mt (84–126 PJ). In reality, this device was developed with an estimated power of 15 Mt (63 PJ), after testing the products "40GN", "245" and "205" its tests were deemed inappropriate and canceled.

The Tsar Bomba differs from its parent design – the RN202 – in several places. The Tsar Bomba was a three-stage bomb with a Trutnev-Babaev second- and third-stage design, with a yield of 50 Mt. This is equivalent to about 1,570 times the combined energy of the bombs that destroyed Hiroshima and Nagasaki, 10 times the combined energy of all the conventional explosives used in World War II, one quarter of the estimated yield of the 1883 eruption of Krakatoa, and 10% of the combined yield of all other nuclear tests to date. A three-stage hydrogen bomb uses a fission bomb primary to compress a thermonuclear secondary, as in most hydrogen bombs, and then uses energy from the resulting explosion to compress a much larger additional thermonuclear stage. There is evidence that the Tsar Bomba had several third stages rather than a single very large one. RDS-202 was assembled on the principle of radiation implosion, which was previously tested during the creation of RDS-37. Since it used a much-heavier secondary module than in the RDS-37, not one, but two primary modules (charges), located on two opposite sides of the secondary module, were used to compress it. This physical charging scheme was later used in the design of the AN-602, but the AN-602 thermonuclear charge itself (secondary module) was new. The RDS-202 thermonuclear charge was manufactured in 1956, and was planned for testing in 1957, but was not tested and put into storage. Two years after the manufacture of the RDS-202, in July 1958, it was decided to remove it from storage, dismantle and use automation units and charge parts for experimental work (Order No. 277 of the Ministry of Medium Machine Building dated May 23, 1957). The CPSU Central Committee and the Council of Ministers of the USSR adopted a draft Joint Resolution on 12 March, 1956, on the preparation and testing of izdeliye 202, which read:

Adopt a draft resolution of the CPSU Central Committee and the USSR Council of Ministers on the preparation and testing of izdeliye 202.

Paragraphs required for inclusion in the draft resolution:

(a) The Ministry of Medium Engineering (Comrade Avraami Zavenyagin) and the Ministry of Defense of the USSR (Comrade Georgy Zhukov) at the end of the preparatory work for the test of izdeliye 202 to report to the CPSU Central Committee on the situation;

(b) The Ministry of Medium Engineering (Comrade Zavenyagin) to solve the issue of introducing a special stage of protection into the design of izdeliye 202 to ensure disarming of the product in the event of a failure of the parachute system, as well as their proposals reported to the CPSU Central Committee.

Comrades Boris Vannikov and Kurchatov are assigned to edit the final version of this resolution.

Product 602

In 1960, KB-11 began developing a thermonuclear device with a design capacity of one hundred megatons of TNT (four hundred and eighteen petajoules). In February 1961, the leaders of KB-11 sent a letter to the Central Committee of the CPSU with the subject line "Some questions of the development of nuclear weapons and methods of their use", which, among other things, raised the question of the expediency of developing such a 100 Mt device. On July 10, 1961, a discussion took place in the Central Committee of the CPSU, at which First Secretary Nikita Khrushchev supported the development and testing of this super-powerful bomb.

To speed up the work on Tsar Bomba, it was based on the 202 Project, but was a new project, developed by a different group. In particular, in KB-11, six casings for the Project 202 bomb already manufactured at NII-1011 and a set of equipment developed for the 202 Project testing were used.

Tsar Bomba had a "three-stage" design: the first stage is the necessary fission trigger. The second stage was two relatively small thermonuclear charges with a calculated contribution to the explosion of 1.5 Mt (6 PJ), which were used for radiation implosion of the third stage, the main thermonuclear module located between them, and starting a thermonuclear reaction in it, contributing 50 Mt of explosion energy. As a result of the thermonuclear reaction, huge numbers of high-energy fast neutrons were formed in the main thermonuclear module, which, in turn, initiated the fast fission nuclear reaction in the nuclei of the surrounding uranium-238, which would have added another 50 Mt of energy to the explosion, so that the estimated energy release of Tsar Bomba was around 100 Mt.

The test of such a complete three-stage 100 Mt bomb was rejected due to the extremely high level of radioactive contamination that would be caused by the fission reaction of large quantities of uranium-238 fission. During the test, the bomb was used in a two-stage version. A. D. Sakharov suggested using nuclear passive material instead of the uranium-238 in the secondary bomb module, which reduced the bomb's energy to 50 Mt, and, in addition to reducing the amount of radioactive fission products, avoided the fireball's contact with the Earth's surface, thus eliminating radioactive contamination of the soil and the distribution of large amounts of fallout into the atmosphere.

Many technical innovations were applied in the design of Tsar Bomba. The thermonuclear charge was made according to the "bifilar" scheme – the radiation implosion of the main thermonuclear stage was carried out from two opposite sides. These secondary charges produced X-ray compression of the main thermonuclear charge. For this, the second stage was separated into two fusion charges which were placed in the front and rear parts of the bomb, for which a synchronous detonation was required with a difference in initiation of no more than 100 nanoseconds. To ensure synchronous detonation of charges with the required accuracy, the sequencing unit of the detonation electronics was modified at KB-25 (now "Federal State Unitary Enterprise "NL Dukhov All-Russian Scientific Research Institute of Automation")(VNIIA).

Development of the carrier aircraft

The initial three-stage design of Tsar Bomba was capable of yielding approximately 100 Mt through fast fission (3,000 times the power of the Hiroshima and Nagasaki bombs); however, it was thought that this would have resulted in too much nuclear fallout, and the aircraft delivering the bomb would not have had enough time to escape the explosion. To limit the amount of fallout, the third stage and possibly the second stage had a lead tamper instead of a uranium-238 fusion tamper (which greatly amplifies the fusion reaction by fissioning uranium atoms with fast neutrons from the fusion reaction). This eliminated fast fission by the fusion-stage neutrons so that approximately 97% of the total yield resulted from thermonuclear fusion alone (as such, it was one of the "cleanest" nuclear bombs ever created, generating a very low amount of fallout relative to its yield). There was a strong incentive for this modification, since most of the fallout from a test of the bomb would probably have descended on populated Soviet territory.

The first studies on "Topic 242" began immediately after Igor Kurchatov talked with Andrei Tupolev (then held in late 1954). Tupolev appointed his deputy for weapon systems, Aleksandr Nadashkevich, as the head of the Topic. Subsequent analysis indicated that to carry such a heavy, concentrated load, the Tu-95 bomber carrying the Tsar Bomba needed to have its engines, bomb bay, suspension and release mechanisms extensively redesigned. The Tsar Bomba's dimensional and weight drawings were passed in the first half of 1955, together with its placement layout drawing. The Tsar Bomba's weight accounted for 15% of the weight of its Tu-95 carrier as expected. The carrier, aside from having its fuel tanks and bomb bay doors removed, had its BD-206 bomb-holder replaced by a new, heavier beam-type BD7-95-242 (or BD-242) holder attached directly to the longitudinal weight-bearing beams. The problem of how to release the bomb was also solved; the bomb-holder would release all three of its locks in a synchronous fashion via electro-automatic mechanisms as required by safety protocols.

A Joint Resolution of the CPSU Central Committee and the Council of Ministers (Nr. 357-28ss) was issued on 17 March, 1956, which mandated that OKB-156 begin conversion of a Tu-95 bomber into a high-yield nuclear bomb carrier. These works were carried out in the Gromov Flight Research Institute from May to September 1956. The converted bomber, designated the Tu-95V, was accepted for duty and was handed over for flight tests which, including a release of a mock-up "superbomb", were conducted under the command of Colonel S. M. Kulikov until 1959, and passed without major issues.

Despite the creation of the Tu-95V bomb-carrier aircraft, the test of the Tsar Bomba was postponed for political reasons: namely, Khrushchev's visit to the United States and a pause in the Cold War. The Tu-95V during this period was flown to Uzyn, in today's Ukraine, and was used as a training aircraft; therefore, it was no longer listed as a combat aircraft. With the beginning of a new round of the Cold War in 1961, the test was resumed. The Tu-95V had all connectors in its automatic release mechanism replaced, the bomb bay doors removed and the aircraft itself covered with a special, reflective white paint.

In late 1961, the aircraft was modified for testing Tsar Bomba at the Kuibyshev aircraft plant.

Site of the detonation

Test

Nikita Khrushchev, the first secretary of the Communist Party, announced the upcoming tests of a 50-Mt bomb in his opening report at the 22nd Congress of the Communist Party of the Soviet Union on October 17, 1961. Before the official announcement, in a casual conversation, he told an American politician about the bomb, and this information was published on September 8, 1961, in The New York Times. The Tsar Bomba was tested on October 30, 1961.

The Tupolev Tu-95V aircraft, No. 5800302, with the bomb took off from the Olenya airfield, and was flown to State Test Site No. 6 of the USSR Ministry of Defense located on Novaya Zemlya with a crew of nine:

  • Test pilot – Major Andrei Yegorovich Durnovtsev
  • Lead navigator of tests – Major Ivan Nikiforovich Kleshch
  • Second pilot – Captain Mikhail Konstantinovich Kondratenko
  • Navigator-operator of the radar – Lieutenant Anatoly Sergeevich Bobikov
  • Radar operator – Captain Alexander Filippovich Prokopenko
  • Flight engineer – Captain Grigory Mikhailovich Yevtushenko
  • Radio operator – Lieutenant Mikhail Petrovich Mashkin
  • Gunner-radio operator – Captain Vyacheslav Mikhailovich Snetkov
  • Gunner-radio operator – Corporal Vasily Yakovlevich Bolotov

The test was also attended by the Tupolev Tu-16 laboratory aircraft, no. 3709, equipped for monitoring the tests, and its crew:

  • Leading test pilot – Lieutenant Colonel Vladimir Fyodorovich Martynenko
  • Second pilot – Senior Lieutenant Vladimir Ivanovich Mukhanov
  • Leading navigator – Major Semyon Artemievich Grigoryuk
  • Navigator-operator of the radar – Major Vasily Timofeevich Muzlanov
  • Gunner-radio operator – Senior Sergeant Mikhail Emelyanovich Shumilov

Both aircraft were painted with special reflective paint to minimize heat damage. Despite this effort, Durnovtsev, and his crew, were given only a 50% chance of surviving the test.

The bomb, weighing 27 tonnes (30 short tons), was so large (8 m (26 ft) long by 2.1 m (6 ft 11 in) in diameter) that the Tu-95V had to have its bomb bay doors and fuselage fuel tanks removed. The bomb was attached to an 800-kilogram (1,800 lb), 1,600-square-metre (17,000 sq ft) parachute, which gave the release and observer planes time to fly about 45 km (28 mi) away from ground zero, giving them a 50 percent chance of survival. The bomb was released two hours after takeoff from a height of 10,500 m (34,449 ft) on a test target within Sukhoy Nos. The Tsar Bomba detonated at 11:32 (or 11:33; USGS earthquake monitors list the event as occurring at 11:33:31 ) Moscow Time on October 30, 1961, over the Mityushikha Bay nuclear testing range (Sukhoy Nos Zone C), at a height of 4,200 m (13,780 ft) ASL (4,000 m (13,123 ft) above the target) (some sources suggest 3,900 m (12,795 ft) ASL and 3,700 m (12,139 ft) above target, or 4,500 m (14,764 ft)). By this time the Tu-95V had already escaped to 39 km (24 mi) away, and the Tu-16 53.5 km (33.2 mi) away. When detonation occurred, the shock wave caught up with the Tu-95V at a distance of 115 km (71 mi) and the Tu-16 at 205 km (127 mi). The Tu-95V dropped 1 kilometre (0.62 mi) in the air because of the shock wave but was able to recover and land safely. According to initial data, the Tsar Bomba had a nuclear yield of 58.6 Mt (245 PJ) (significantly exceeding what the design itself would suggest) and was overestimated at values all the way up to 75 Mt (310 PJ).

The Tsar Bomba's fireball, about 8 km (5.0 mi) wide at its maximum, was prevented from touching the ground by the shock wave, but reached nearly 10.5 km (6.5 mi) in the sky – the altitude of the deploying bomber.

Although simplistic fireball calculations predicted it would be large enough to hit the ground, the bomb's own shock wave bounced back and prevented this. The 8-kilometre-wide (5.0 mi) fireball reached nearly as high as the altitude of the release plane and was visible at almost 1,000 km (620 mi) away. The mushroom cloud was about 67 km (42 mi) high (nearly eight times the height of Mount Everest), which meant that the cloud was above the stratosphere and well inside the mesosphere when it peaked. The cap of the mushroom cloud had a peak width of 95 km (59 mi) and its base was 40 km (25 mi) wide.

A Soviet cameraman said:

The clouds beneath the aircraft and in the distance were lit up by the powerful flash. The sea of light spread under the hatch and even clouds began to glow and became transparent. At that moment, our aircraft emerged from between two cloud layers and down below in the gap a huge bright orange ball was emerging. The ball was powerful and arrogant like Jupiter. Slowly and silently it crept upwards ... Having broken through the thick layer of clouds it kept growing. It seemed to suck the whole Earth into it. The spectacle was fantastic, unreal, supernatural."

Test results

The explosion of Tsar Bomba, according to the classification of nuclear explosions, was an ultra-high-power low-air nuclear explosion.

The mushroom cloud of Tsar Bomba seen from a distance of 161 km (100 mi). The crown of the cloud is 65 km (40 mi) high at the time of the picture. (source: Rosatom State Corporation Communications Department 20-08-2020)
  • The flare was visible at a distance of more than 1,000 km (620 mi). It was observed in Norway, Greenland and Alaska.
  • The explosion's nuclear mushroom rose to a height of 67 km (42 mi). The shape of the "hat" was two-tiered; the diameter of the upper tier was estimated at 95 km (59 mi), the lower tier at 70 km (43 mi). The cloud was observed 800 km (500 mi) from the explosion site.
  • The blast wave circled the globe three times, with the first one taking 36 hours and 27 minutes.
  • A seismic wave in the earth's crust, generated by the shock wave of the explosion, circled the globe three times.
  • The atmospheric pressure wave resulting from the explosion was recorded three times in New Zealand: the station in Wellington recorded an increase in pressure at 21:57, on October 30, coming from the north-west, at 07:17 on October 31, from the southeast, and at 09:16, on November 1, from the northwest (all GMT time), with amplitudes of 0.6 mbar (0.60 hPa), 0.4 mbar (0.40 hPa), and 0.2 mbar (0.20 hPa). Respectively, the average wave speed is estimated at 303 m/s (990 ft/s), or 9.9 degrees of the great circle per hour.
  • Glass shattered in windows 780 km (480 mi) from the explosion in a village on Dikson Island.
  • The sound wave generated by the explosion reached Dikson Island, but there are no reports of destruction or damage to structures even in the urban-type settlement of Amderma, which is much closer (280 km (170 mi)) to the landfall.
  • Ionization of the atmosphere caused interference to radio communications even hundreds of kilometers from the test site for about 40 minutes.
  • Radioactive contamination of the experimental field with a radius of 2–3 km (1.2–1.9 mi) in the epicenter area was no more than 1 milliroentgen / hour. The testers appeared at the explosion site 2 hours later; radioactive contamination posed practically no danger to the test participants.

All buildings in the village of Severny, both wooden and brick, located 55 km (34 mi) from ground zero within the Sukhoy Nos test range, were destroyed. In districts hundreds of kilometres from ground zero, wooden houses were destroyed; stone ones lost their roofs, windows, and doors; and radio communications were interrupted for almost one hour. One participant in the test saw a bright flash through dark goggles and felt the effects of a thermal pulse even at a distance of 270 km (170 mi). The heat from the explosion could have caused third-degree burns 100 km (62 mi) away from ground zero. A shock wave was observed in the air at Dikson settlement 700 km (430 mi) away; windowpanes were partially broken for distances up to 900 kilometres (560 mi). Atmospheric focusing caused blast damage at even greater distances, breaking windows in Norway and Finland. Despite being detonated 4.2 km (3 mi) above ground, its seismic body wave magnitude was estimated at 5.0–5.25.

Reactions

Immediately after the test, several US Senators condemned the Soviet Union. Prime Minister of Sweden Tage Erlander saw the blast as the Soviets' answer to a personal appeal to halt nuclear testing that he had sent the Soviet leader in the week prior to the blast. The British Foreign Office, Prime Minister of Norway Einar Gerhardsen, Prime Minister of Denmark Viggo Kampmann and others also released statements condemning the blast. Soviet and Chinese radio stations mentioned the US underground nuclear test of a much smaller bomb (possibly the Mink test) carried out the day prior, without mentioning the Tsar Bomba test.

Consequences of the test

The creation and testing of a superbomb were of great political importance; the Soviet Union demonstrated its potential in creating a nuclear arsenal of great power (at that time, the most powerful thermonuclear charge tested by the United States was 15 Mt (Castle Bravo)). After the Tsar Bomba test, the United States did not increase the power of its own thermonuclear tests and, in 1963 in Moscow, the Treaty Banning Nuclear Weapon Tests in the Atmosphere, Outer Space and Under Water was signed.

The scientific result of the test was the experimental verification of the principles of calculation and design of multistage thermonuclear charges. It was experimentally proven that there is no fundamental limitation on increasing the power of a thermonuclear charge. However, as early as October 30, 1949, three years before the Ivy Mike test which utilized the Teller-Ulam design, in the Supplement to the official report of the General Advisory Committee of the US Atomic Energy Commission, nuclear physicists Enrico Fermi and Isidor Isaac Rabi observed that thermonuclear weapons have "unlimited destructive power". In the tested specimen of the bomb, to raise the explosion power by another 50 Mt, it was enough to replace the lead sheath with uranium-238, as was normally expected. The replacement of the cladding material and the decrease in the explosion power were motivated by the desire to reduce the amount of radioactive fallout to an acceptable level, and not by the desire to reduce the weight of the bomb, as is sometimes believed. The weight of Tsar Bomba did decrease from this, but insignificantly. The uranium cladding was supposed to weigh about 2,800 kg (6,200 lb), the lead sheath of the same volume – based on the lower density of lead – is about 1,700 kg (3,700 lb). The resulting relief of just over one ton is weakly noticeable with a total mass of Tsar Bomba of at least 24 tons and did not affect the state of affairs with its transportation.

The explosion is one of the cleanest in the history of atmospheric nuclear tests per unit of power. The first stage of the bomb was a uranium charge with a capacity of 1.5 Mt, which in itself provided a large amount of radioactive fallout; nevertheless, it can be assumed that Tsar Bomba was really relatively clean – more than 97% of the explosion power was provided by a thermonuclear fusion reaction, which practically does not create radioactive contamination.

A distant consequence was the increased radioactivity accumulated in the glaciers of Novaya Zemlya. According to the 2015 expedition, due to nuclear tests, the glaciers of Novaya Zemlya are 65–130 times more radioactive than the background in neighboring areas, including contamination from the tests of the Kuzka's Mother.

Sakharov was against nuclear proliferation, and played a key role in signing the 1963 Partial Test Ban Treaty. Sakharov became an advocate of civil liberties and reforms in the Soviet Union. These efforts earned him the Nobel Peace Prize in 1975.

Analysis

Total destructive radius, superimposed on Paris with the red circle indicating the area of total destruction (radius 35 kilometres [22 mi]), and the yellow circle the radius of the fireball (radius 3.5 kilometres [2 mi])

The Tsar Bomba is the single most physically powerful device ever deployed on Earth, the most powerful nuclear bomb tested and the largest man-made explosion in history. For comparison, the largest weapon ever produced by the US, the now-decommissioned B41, had a predicted maximum yield of 25 Mt (100 PJ). The largest nuclear device ever tested by the US (Castle Bravo) yielded 15 Mt (63 PJ) because of an unexpectedly-high involvement of lithium-7 in the fusion reaction; the preliminary prediction for the yield was from 4 to 6 Mt (17 to 25 PJ). The largest weapons deployed by the Soviet Union were also around 25 Mt (100 PJ) (e.g., the SS-18 Mod. 3 warhead).

The weight and size of the Tsar Bomba limited the range and speed of the specially-modified bomber carrying it. Delivery by an intercontinental ballistic missile would have required a much stronger missile (the Proton started its development as that delivery system). It has been estimated that detonating the original 100 Mt (420 PJ) design would have increased the world's total fission fallout since the invention of the atomic bomb by 25%. It was decided that a full 100 Mt detonation would create a nuclear fallout that was unacceptable in terms of pollution from a single test, as well as a near-certainty that the release plane and crew would be destroyed before it could escape the blast radius.

The Tsar Bomba was the culmination of a series of high-yield thermonuclear weapons designed by the Soviet Union and the United States during the 1950s (e.g., the Mark 17 and B41 nuclear bombs).

Practical applications

Tsar Bomba was never a practical weapon; it was a single product, the design of which allowed reaching a power of 100 Mt TE. The test of a 50-Mt bomb was, among other things, a test of the performance of the product design for 100 Mt. The bomb was intended exclusively to exert psychological pressure on the United States.

Experts began to develop military missiles for warheads (150 Mt and more) that have been redirected for space use:

  • UR-500 – (warhead mass – 40 tons, virtually implemented as a carrier rocket – "Proton" – GRAU index – 8K82)
  • N-1 – (warhead mass – 75–95 t (74–93 long tons; 83–105 short tons), the development was reoriented into a carrier for the lunar program, the project was brought to the stage of flight design tests and closed in 1976, GRAU index – 11A52)
  • R-56 – (GRAU index – 8K67)

Films

  • Footage from a Soviet documentary about the bomb is featured in Trinity and Beyond: The Atomic Bomb Movie (Visual Concept Entertainment, 1995), where it is referred to as the Russian monster bomb. The video states that the Tsar Bomba project broke the voluntary moratorium on nuclear tests. In fact, the Soviets restarted their tests and broke the unilateral voluntary moratorium 30 days before Tsar Bomba, testing 45 times in that month. Since the moratorium was unilateral there was no multilateral legal obstacle. The US had declared their own one-year unilateral moratorium on nuclear tests and, as that year had expired, the US had already announced that it considered itself free to resume testing without further notice. Later, it was stated that the US had not resumed testing at the time of the Tsar Bomba test. That announcement was in error, as the US had in fact tested five times under Operation Nougat between the USSR's ending of the moratorium on 1 October and the Tsar Bomba test on 30 October.
  • "World's Biggest Bomb", a 2011 episode of the PBS documentary series Secrets of the Dead produced by Blink Films & WNET, chronicles the events leading to the detonations of Castle Bravo and the Tsar Bomba.
  • In connection with the celebration of 75 years of nuclear industry, Rosatom released a declassified Russian language documentary video of the Tsar Bomba test on YouTube in August 2020.

Introduction to entropy

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Introduct...