Salted bomb
Encyclopedia
A salted bomb is a variation of a nuclear weapon
designed to produce enhanced quantities of radioactive fallout, rendering a large area uninhabitable. The term is derived both from the means of their manufacture, which involves the incorporation of additional elements to a standard atomic weapon, and from the expression "to salt the earth
", meaning to render an area uninhabitable for generations. The idea originated with Hungarian-American physicist Leo Szilard
, in February 1950. His intent was not to propose that such a weapon be built, but to show that nuclear weapon technology would soon reach the point where it could end human life on Earth.
Salted versions of both fission and fusion weapons can be made by surrounding the core of the explosive device with a material containing an element that can be converted to a highly radioactive isotope by neutron
bombardment. When the bomb explodes, the element absorbs neutrons released by the nuclear reaction, converting it to its radioactive form. The explosion scatters the resulting radioactive material over a wide area, leaving it uninhabitable far longer than an area affected by typical nuclear weapons.
In a salted hydrogen bomb, the radiation case around the fusion fuel, which normally is made of some fissionable element
, is replaced with a metallic salting element. Salted fission bombs can be made by replacing the neutron reflector
between the fissionable core and the explosive layer with a metallic element. The energy yield
from a salted weapon is usually lower than from an ordinary weapon of similar size as a consequence of these changes.
The radioactive isotope chosen for the fallout material is usually a high intensity gamma ray
emitter, with a half-life
long enough that it remains lethal for an extended period. It also must have a chemistry that causes it to return to earth as fallout, rather than stay in the atmosphere after being vaporized in the explosion.
One example of a salted bomb is a proposed cobalt bomb
, which produces the radioactive isotope cobalt-60 (60Co
). Other non-fissionable isotopes can be produced, including gold-198
(198Au), tantalum-182 (182Ta) and zinc-65
(65Zn). Sodium-23 has also been proposed as a salting agent.
No salted bomb has ever been atmospherically tested and as far as is publicly known none have ever been built. The United Kingdom did test a 1 kiloton bomb incorporating a small amount of cobalt as an experimental radiochemical tracer
at their Tadje
testing site in Maralinga
range, Australia on September 14, 1957.
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
designed to produce enhanced quantities of radioactive fallout, rendering a large area uninhabitable. The term is derived both from the means of their manufacture, which involves the incorporation of additional elements to a standard atomic weapon, and from the expression "to salt the earth
Salting the earth
Salting the earth, or sowing with salt, is the ritual of spreading salt on conquered cities to symbolize a curse on its re-inhabitation. It originated as a practice in the ancient Near East and became a well-established folkloric motif in the Middle Ages.-Destroying cities:The custom of purifying...
", meaning to render an area uninhabitable for generations. The idea originated with Hungarian-American physicist Leo Szilard
Leó Szilárd
Leó Szilárd was an Austro-Hungarian physicist and inventor who conceived the nuclear chain reaction in 1933, patented the idea of a nuclear reactor with Enrico Fermi, and in late 1939 wrote the letter for Albert Einstein's signature that resulted in the Manhattan Project that built the atomic bomb...
, in February 1950. His intent was not to propose that such a weapon be built, but to show that nuclear weapon technology would soon reach the point where it could end human life on Earth.
Salted versions of both fission and fusion weapons can be made by surrounding the core of the explosive device with a material containing an element that can be converted to a highly radioactive isotope by neutron
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
bombardment. When the bomb explodes, the element absorbs neutrons released by the nuclear reaction, converting it to its radioactive form. The explosion scatters the resulting radioactive material over a wide area, leaving it uninhabitable far longer than an area affected by typical nuclear weapons.
In a salted hydrogen bomb, the radiation case around the fusion fuel, which normally is made of some fissionable element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
, is replaced with a metallic salting element. Salted fission bombs can be made by replacing the neutron reflector
Neutron reflector
A neutron reflector is any material that reflects neutrons. This refers to elastic scattering rather than to a specular reflection. The material may be graphite, beryllium, steel, and tungsten carbide, or other materials...
between the fissionable core and the explosive layer with a metallic element. The energy yield
Nuclear weapon yield
The explosive yield of a nuclear weapon is the amount of energy discharged when a nuclear weapon is detonated, expressed usually in the equivalent mass of trinitrotoluene , either in kilotons or megatons , but sometimes also in terajoules...
from a salted weapon is usually lower than from an ordinary weapon of similar size as a consequence of these changes.
The radioactive isotope chosen for the fallout material is usually a high intensity gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
emitter, with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
long enough that it remains lethal for an extended period. It also must have a chemistry that causes it to return to earth as fallout, rather than stay in the atmosphere after being vaporized in the explosion.
One example of a salted bomb is a proposed cobalt bomb
Cobalt bomb
A cobalt bomb is a theoretical type of "salted bomb": a nuclear weapon intended to contaminate an area by radioactive material, with a relatively small blast....
, which produces the radioactive isotope cobalt-60 (60Co
Cobalt-60
Cobalt-60, , is a synthetic radioactive isotope of cobalt. Due to its half-life of 5.27 years, is not found in nature. It is produced artificially by neutron activation of . decays by beta decay to the stable isotope nickel-60...
). Other non-fissionable isotopes can be produced, including gold-198
(198Au), tantalum-182 (182Ta) and zinc-65
(65Zn). Sodium-23 has also been proposed as a salting agent.
No salted bomb has ever been atmospherically tested and as far as is publicly known none have ever been built. The United Kingdom did test a 1 kiloton bomb incorporating a small amount of cobalt as an experimental radiochemical tracer
Radioactive tracer
A radioactive tracer, also called a radioactive label, is a substance containing a radioisotope that is used to measure the speed of chemical processes and to track the movement of a substance through a natural system such as a cell or tissue...
at their Tadje
British nuclear tests at Maralinga
British nuclear tests at Maralinga occurred between 1955 and 1963 at the Maralinga site, part of the Woomera Prohibited Area, in South Australia. A total of seven major nuclear tests were performed, with approximate yields ranging from 1 to 27 kilotons of TNT equivalent...
testing site in Maralinga
British nuclear tests at Maralinga
British nuclear tests at Maralinga occurred between 1955 and 1963 at the Maralinga site, part of the Woomera Prohibited Area, in South Australia. A total of seven major nuclear tests were performed, with approximate yields ranging from 1 to 27 kilotons of TNT equivalent...
range, Australia on September 14, 1957.