RDS-1

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Nuclear test
Pervaya Molnija ("First Lightning")
nation Soviet Union 1923Soviet Union Soviet Union
Test location Semipalatinsk
date August 29, 1949
Test type Above-ground test
Test height 30 meters
Weapon type fission
Explosive power 22 kT

RDS-1 (Russian: РДС-1 for Реактивный Двигатель Специальный , Reaktiwny Dwigatel Spezialny, also "Object 501") is the name of the first nuclear weapon that was developed as part of the Soviet atomic bomb project. It was also the first nuclear weapon to be developed outside of the United States . The successful test took place on August 29, 1949. RDS-1 is an extensive copy of the US Mk.3 design (Fat Man) .

development

During the Second World War , the Soviet Union received extensive information about the American-British-Canadian nuclear weapons program ( Manhattan Project ). The Soviet Union received detailed technical data on nuclear weapons under development in the USA from the most important spies Klaus Fuchs , Theodore Hall and David Greenglass . Klaus Fuchs passed on information to the Soviet Union from 1941. He was part of the British Tube Alloy delegation and, among other things, made important contributions to the development of the implosion design for the American Mk.3 bomb. This gave him access to all important aspects of nuclear weapons development in Los Alamos , which he passed on to the Soviet Union. The young physicist Theodore Hall came to Los Alamos at the age of 19 and worked there on the development of implosion techniques. He worked as a Soviet spy from 1944. David Greenglas was a US Army mechanic who worked in Los Alamos from August 1944. Greenglas was in a laboratory and converted the scientists' theoretical designs into test units. Although he did not hold a leading position, he was given detailed access to the implosion instructions for the Mk.3 bomb, which he passed on to the Soviet Union through his brother-in-law Julius Rosenberg .

The Soviet physicists, who worked on the development of nuclear weapons under the scientific leadership of Igor Kurchatov , were able to follow the development of the first nuclear weapons in the USA and understand the foreign knowledge through their own theoretical analyzes and experimental measurements. However, until the end of the war, the Soviet Union lacked the resources to develop an industrial nuclear weapons program. This changed suddenly with the end of the war, and under the direction of the head of the secret service Lavrenti Beria a radical program was started to convert the theoretical knowledge into a real weapon.

This raised the question of which design should be used for the first Soviet weapon. Most of the scientists advocated the development of their own design. On the one hand, this was due to the fact that the first American nuclear weapons had many technical inadequacies, since they were also the product of a radical program aimed at developing a nuclear weapon as quickly as possible. Second, for reasons of pride, the Soviet scientists did not want their first nuclear weapon to be just a copy, but rather an independent product of Soviet science. On the other hand, the Soviet leadership, especially Beria, wanted a low-risk program that would make a nuclear weapon available to the Soviet Union as quickly as possible. He therefore insisted on realizing the American designs true to the original. Beria enforced his point of view at the end of 1945, whereupon the physicist and hero of the work Pjotr ​​Leonidowitsch Kapiza complained in a personal letter to Stalin on October 3, 1945:

“The main shortcomings of our current approach are that they fail to take advantage of our organizational capabilities and that it is unoriginal. We're trying to repeat everything the Americans did instead of trying to find our own way. We forget that following the American way is not within our means and would take too long. ... Comrade Beria, Malenkov and Vosnesensky act like supermen in the special committee, especially Comrade Beria. It is correct that he is holding the conductor's baton in his hand. This is fine, but according to him, a scientist should play the first violin because it is the violin that sets the tone for the entire orchestra. Comrade Beria's fundamental weakness is that as a conductor he should not only swing the baton but also understand the score. ” (Indirect translation from English)

The letter ended with the threat that Kapiza would leave the program if Stalin does not intervene. However, Beria prevailed with the development of a copy of the American bomb, and Kapiza abandoned the Soviet nuclear weapons project in December 1945.

With the establishment of the first Soviet nuclear weapons center, Arsamas-16, in 1946, scientists were given a tight time frame. The final drafts for RDS-1 (the copy of the Mk.3 Fat Man draft) and RDS-2 (the copy of the Mk.1 Little Boy draft) should be completed by July 1, 1947. RDS-1 should be ready for testing on January 1, 1948 and RDS-2 on June 1, 1948. The program made good theoretical progress, but various delays in the construction of the industrial nuclear weapons complex made it impossible to keep this tight schedule.

The first Soviet production reactor for the extraction of plutonium only became critical on June 19, 1948. Reactor A of the Mayak nuclear facility had an initial output of 100 MW th . Its first production run lasted around 100 days, plus around 30 to 40 days of cooldown for the irradiated fuel. On April 16, 1949, the first plutonium was extracted from this fuel, a total of 16.5 kg. This enabled the first Soviet nuclear weapon to be completed.

The first test and later developments

The Soviet Union selected a steppe area near Semipalatinsk in the Kazakh SSR as a nuclear weapons test site in 1947. After a few changes of name, it was finally run as State Central Scientific Test Site No. 2 ( GosZNIP-2 ). A separate town, Semipalatinsk-21 (today Kurchatov ), and a special cordoned-off area for the storage of nuclear weapon components were built for the staff of the test site . Preparations for the first test began in April 1949. Kurchatov traveled to Semipalatinsk in May 1949 to support the test preparations. The material for the first test was transported to Semipalatinsk by rail. The train stations along the route were closed to the public, and scientists on board the trains were not allowed to leave them during the brief stops along the route.

For the first test, a 30 m high tower was built on which the bomb was to be detonated. In contrast to the first American nuclear weapon test “ Trinity ” in July 1945, the bomb was not finally assembled on the tower, but in a hall next to the tower. Also in contrast to “Trinity”, wooden and brick houses, bridges, tunnels, water towers and other facilities were built near the bomb tower. Locomotives, railroad cars and tanks were also positioned. The aim was to test the effects of the first Soviet nuclear weapon explosion on such structures and vehicles. A state special commission found the area ready for testing on August 10th. On August 14th, 18th and 22nd there were several test runs in preparation for the actual test.

The parts of the bomb were delivered by truck from Semipalatinsk-21, and final assembly began on August 28, under the supervision of Kurchatov and in the presence of Beria. The bomb was mounted on a rail-bound wagon. At around 2 a.m. on August 29, RDS-1 was completed. The bomb was pushed to the tower on its car and transported to the top of the tower by a freight elevator. Once there, it was connected to the ignition system. Then the design team left the test site. The control and observation bunker was around 8 km away. Because it was drizzling all night, the test, which was scheduled for 6 a.m. local time, was postponed by an hour. The sky remained overcast, but it cleared enough that the observation conditions were good enough for the test. The automatic countdown began 30 minutes before the ignition. At 7 a.m. local time, RDS-1 detonated with an explosive force of around 22 kT. Beria hugged Khariton and Kurchatov immediately after the successful ignition . He immediately had two observers who had attended the American Operation Crossroads in 1946 confirm that the explosion had looked like that of the Americans. Shortly afterwards he called Stalin in Moscow to inform him personally. He already knew about the successful test and hung up, which caused Beria to get extremely upset.

The Soviet Union kept its first successful nuclear weapon test secret. However, at this time the USA and Great Britain were already running an intensive measurement program to detect radioactivity in the atmosphere . On September 3, 1949, an American WB-29 measurement aircraft east of Kamchatka collected radioactive particles from the "First Lightning" in its filters . A laboratory quickly found that these particles were caused by nuclear fission . In the following days the radioactive cloud could be tracked over the USA. The commercial laboratory Tracerlab determined the time of the explosion to be midnight GMT on August 29 (6 a.m. local time in Semipalatinsk), which was only an hour off. Defense Secretary Louis A. Johnson initially refused to be convinced by a Soviet test. However, on September 23 , President Harry Truman publicly announced that a nuclear test had taken place in the Soviet Union in recent weeks. The USA named the test "Joe-1".

Despite the successful test, the construction of the Soviet nuclear arsenal was slow. Problems with the first production reactors and the transition from research and development to series production made the Soviet arsenal grow very slowly. According to a source, there was another attempt with a test bomb in 1950, which failed, but other sources and the official list of Soviet nuclear weapons tests do not show a test in 1950. In December 1951, the first three modified RDS-1 bombs ("Object 501M") were completed. Like the first American bombs, however, these were not placed under the control of the armed forces, but stored in separate parts in separate facilities. At this point in time, the Soviet Union had already tested its own implosion draft under the name RDS-2 in the "Second Lightning" test on September 24, 1952. Although the designation RDS-2 was retained, this bomb has nothing in common with the copy of Little Boy originally intended under this name. All in all, only five RDS-1 series models are said to have been built. The numerically significant series production of nuclear weapons began in the Soviet Union in 1953 with RDS-3 , an implosion design with a composite core consisting of plutonium and highly enriched uranium with about 20 pieces per year.

construction

RDS-1 is a nuclear fission bomb based on the implosion principle and uses plutonium as a fission material. Since it is a replica of the American Mk.3 design, the basic structure can be read there: Structure of the Mk.3 bomb .

In 2013, the Central Archives of the Russian Federation published historical documents, which also made some specific details about RDS-1 public. A handwritten draft for a ministerial decree to conduct a nuclear weapon test by Kurchatov, dated August 18, 1949 (ten days before the first test), contains the following passages, among others:

a) Plutonium charge:
Mass of the load: 6403.39 g
outer diameter: 93 millimeters
inner diameter: 28 mm;
b) expected efficiency of the cargo: = ~ 10%, which is equivalent to an explosion of 10,000 t TNT;
c) the expected probability of an explosion with reduced efficiency is = ~ 10% (of which in 5% of the cases an expected explosive force of 10,000 to 3000 tons of TNT and in 5% of the cases - less than 3000 tons but not less than 300 tons of TNT)

(indirect translation from English)

According to this information, the plutonium core of RDS-1 was slightly heavier than that in the first American test "Trinity", which used 6.1 kg of plutonium. From the data, a density of the core of 15.6 g / cm³ could be calculated, which corresponds to a δ-phase -plutonium- gallium -alloy with 1.6% gallium. Furthermore, based on the Soviet plutonium production data, the proportion of 240 Pu can be estimated at 0.7%.

Model of the weapon

Model of the first Soviet atomic bomb in the Moscow Polytechnic Museum

An exhibition in the Moscow Polytechnic Museum commemorates the manufacture and explosion of the first RDS-1 . Among other things, a model of the RDS-1 can be seen there, which, like the real bomb, was built in the small town of Sarov near Nizhny Novgorod . In addition, every visitor can simulate a nuclear test at a control panel at the push of a button.

literature

Web links

Individual evidence

  1. ^ A b c d V. N. Mikhailov, GA Goncharov: IV Kurchatov and the development of nuclear weapons in the USSR. In: Atomic Energy. Vol. 86, no. 4, 1999, pp. 266-282.
  2. ↑ a b c d e J. Baggott: Atomic - The first war of physics and the secret history of the atom bomb: 1939-1949. Icon Books, UK 2009, ISBN 978-1-84831-082-7 .
  3. ↑ a b A. Diakov: The History of Plutonium Production in Russia. (PDF; 265 kB). In: Science & Global Security. 19, 2011, pp. 28-45.
  4. ↑ a b c P. Podvig (Ed.): Russian Strategic Nuclear Forces. MIT Press, 2004, ISBN 0-262-16202-4 .
  5. ↑ a b c R. Rhodes: Dark Sun - The Making of the Hydrogen Bomb. Simon & Schuster, 2005, ISBN 0-684-82414-0 .
  6. ↑ a b c S. J. Zaloga : The Kremlin's Nuclear Sword - The Rise and Fall of Russia's Strategic Nuclear Forces, 1945-2000. Smithsonian Institution Press, 2001, ISBN 1-58834-007-4 .
  7. ↑ ЯДЕРНЫЕ ИСПЫТАНИЯ СССР. ( Memento from July 6, 2013 in the web archive archive.today )
  8. ↑ a b c Details of the RDS-1 device
  9. ↑ Dmitri Romendik: A bomb for world peace. In: Russia Beyond the Headlines. Rossiyskaya Gazeta, September 5, 2014, accessed September 10, 2014 .

Coordinates: 50 ° 26 ′ 16.7 ″  N , 77 ° 48 ′ 51 ″  E