Definition

Improvised Nuclear Devices or (INDs) are theoretical illicit nuclear weapon

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...

s bought, stolen, or otherwise originating from a nuclear state, or a weapon fabricated by a terrorist group from illegally obtained fissile nuclear weapons material that produces a nuclear explosion. An IND would be built from the components of a stolen weapon or from scratch using nuclear material (plutonium

Plutonium

Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...

 or highly enriched uranium

Enriched uranium

Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight...

). It would produce same physical and medical effects as nuclear weapon

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...

. A successful detonation would result in catastrophic loss of life, destruction of infrastructure, and nuclear contamination of a very large area.

Types

If a nuclear yield is NOT achieved, the result would likely resemble a Radiological Dispersal Device

Dirty bomb

A dirty bomb is a speculative radiological weapon that combines radioactive material with conventional explosives. The purpose of the weapon is to contaminate the area around the explosion with radioactive material, hence the attribute "dirty"....

 in which fissile weapons material was dispensed locally. If nuclear yield is achieved, results would resemble a nuclear explosion. Like nuclear explosions, IND explosions can be evaluated with a plume map.

Design considerations

The INDs

Improvised nuclear device

- Definition :Improvised Nuclear Devices or are theoretical illicit nuclear weapons bought, stolen, or otherwise originating from a nuclear state, or a weapon fabricated by a terrorist group from illegally obtained fissile nuclear weapons material that produces a nuclear explosion...

 when built from scratch would most likely be of gun-type

Gun-type fission weapon

Gun-type fission weapons are fission-based nuclear weapons whose design assembles their fissile material into a supercritical mass by the use of the "gun" method: shooting one piece of sub-critical material into another...

 which is fairly easy to design and manufacture (however, requiring highly enriched uranium

Enriched uranium

Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight...

).

Improvised nuclear devices are likely to cause more nuclear fallout

Nuclear fallout

Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...

 because of incomplete fission - due to overengineering the pit

Pit (nuclear weapon)

The pit is the core of an implosion weapon – the fissile material and any neutron reflector or tamper bonded to it. Some weapons tested during the 1950s used pits made with U-235 alone, or in composite with plutonium, but all-plutonium pits are the smallest in diameter and have been the standard...

 (making it heavier to ensure fission

Nuclear fission

In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...

 occurs at least in part of it), using the aforementioned gun-type design or as a result of a fizzle

Fizzle (nuclear test)

In nuclear weapons, a fizzle occurs when the testing of a nuclear bomb fails to meet its expected yield. The reason for the failure can be linked to improper bomb design, poor construction, or lack of expertise. All countries that have had a nuclear weapons testing program have experienced fizzles...

(yield lower than planned due to engineering/manufacturing errors).