Chagan () was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

underground nuclear test Underground nuclear testing is the Nuclear weapons testing, test detonation of nuclear weapons that is performed underground. When the device being tested is buried at sufficient depth, the nuclear explosion may be contained, with no release of ...

conducted at the

Semipalatinsk Test Site The Semipalatinsk Test Site (Russian language, Russian: Семипалатинск-21; Semipalatinsk-21), also known as "The Polygon", was the primary testing venue for the Soviet Union's nuclear weapons. It is located on the steppe in northeast ...

on January 15, 1965.

Description

Chagan was the first and largest of the 124 detonations in the

Nuclear Explosions for the National Economy Nuclear Explosions for the National Economy (russian: Ядерные взрывы для народного хозяйства, Yadernyye vzryvy dlya narodnogo khozyaystva; sometimes referred to as ''Program #7'') was a Soviet program to investiga ...

program, designed to produce

peaceful nuclear explosion Peaceful nuclear explosions (PNEs) are nuclear explosions conducted for non-military purposes. Proposed uses include excavation for the building of canals and harbours, electrical generation, the use of nuclear explosions to drive spacecraft, and a ...

s (PNEs) for earth-moving purposes. The concept of using PNEs to create artificial lakes, harbors and canals was modeled after a United States program,

Project Plowshare Project Plowshare was the overall United States program for the development of techniques to use nuclear explosives for peaceful construction purposes. The program was organized in June 1957 as part of the worldwide Atoms for Peace efforts. As ...

, which conducted the first peaceful nuclear explosion (the 104 kt Sedan shallow cratering test) at the

Nevada Test Site The Nevada National Security Site (N2S2 or NNSS), known as the Nevada Test Site (NTS) until 2010, is a United States Department of Energy (DOE) reservation located in southeastern Nye County, Nevada, about 65 miles (105 km) northwest of th ...

in July 1962. Described as a "near clone" of the Sedan shot, Chagan's yield was the equivalent of 140

kiloton TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a t ...

s of

TNT Trinitrotoluene (), more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagen ...

and sought to produce a large conical crater suitable for a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

. The site was a dry bed of the

Chagan River (tributary of Irtysh River) The Shagan ( kk, Шаған - ''Şağan'') is a river in the east of Kazakhstan and a tributary of the Irtysh. The river is long and the area of its basin is . Geography The Shagan has its sources in the northwestern slopes of the Chingiztau, a ...

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 lake has a diameter of and is deep. Shallow subsurface (open) cratering explosions such as Sedan or Chagan release a great deal of steam and pulverized rock along with approximately 20% of the device's fission products into the atmosphere. Although the vast majority of this fallout was deposited in the general area of the test, it also produced a small but measurable radioactive plume, which in Chagan's case was detected over Japan and initially prompted complaints from the US that the Soviets were violating the provisions of the October 1963

Limited Test Ban Treaty The Partial Test Ban Treaty (PTBT) is the abbreviated name of the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, which prohibited all test detonations of nuclear weapons except for those conducted ...

, which banned atmospheric tests and any vented (or "open") subsurface detonation which caused "radioactive debris to be present outside the territorial limits of the State under whose jurisdiction or control such explosion is conducted". The device itself was a low fission-fraction design, meaning it produced only a small portion of its yield from fission and hence produced less fallout than a military device generally designed for low weight and/or size, and not fallout considerations. The device had a primary (fission) stage of and a purely thermonuclear secondary stage. The photo of the Chagan shot is occasionally confused with that of the Soviet ''

Joe 1 The RDS-1 (russian: РДС-1), also known as Izdeliye 501 (device 501) and First Lightning (), was the nuclear bomb used in the Soviet Union's first nuclear weapon test. The United States assigned it the code-name Joe-1, in reference to Joseph S ...

'' test. The correct image shows a squat, ground-level cloud similar to the Sedan shot rather than the tall

mushroom cloud A mushroom cloud is a distinctive mushroom-shaped flammagenitus cloud of debris, smoke and usually condensed water vapor resulting from a large explosion. The effect is most commonly associated with a nuclear explosion, but any sufficiently ener ...

of the tower-detonated Joe-1.

Lake Chagan

Lake Chagan Lake Chagan (russian: Чаган) or Lake Shagan ( kk, Шаған, ''Şağan''), also known as Lake Balapan, is a lake in Kazakhstan created by the Chagan nuclear test on January 15, 1965, which was conducted as part of the Soviet Union Nucle ...

or Lake Shagan, also known as Balapan, is a

created at the confluence of rivers Shagan and

Ashchysu The Ashchysu ( kk, Ащысу) is a river in the Abai Region, Kazakhstan and a tributary of the Shagan, of the Irtysh basin. The river is long and the area of its basin is .Google Earth Geography The Ashchysu has its sources in the northeas ...

by the Chagan nuclear test roughly in size, is still

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

, and has been called the "Atomic Lake". As at the

Trinity site Trinity was the code name of the first detonation of a nuclear weapon. It was conducted by the United States Army at 5:29 a.m. on July 16, 1945, as part of the Manhattan Project. The test was conducted in the Jornada del Muerto desert abo ...

of the first United States nuclear weapon test in Alamogordo, New Mexico, the exposed rock and sand was melted into a glassy substance called

trinitite Trinitite, also known as atomsite or Alamogordo glass, is the glassy residue left on the desert floor after the plutonium-based Trinity nuclear bomb test on July 16, 1945, near Alamogordo, New Mexico. The glass is primarily composed of arkosic sa ...

References

External links

The Soviet program for peaceful uses of nuclear weapons
{{coord, 49, 56, 7, N, 79, 0, 30, E, type:landmark_region:KZ, display=title 1965 in the Kazakh Soviet Socialist Republic 1965 in military history Explosions in 1965 Peaceful nuclear explosions Soviet nuclear weapons testing Underground nuclear weapons testing January 1965 events in Asia

Description

Lake Chagan

See also

References

External links