Cobalt bomb

A cobalt bomb is a type of "salted bomb": a nuclear weapon designed to produce enhanced amounts of radioactive fallout, intended to contaminate a large area with radioactive material, potentially for the purpose of radiological warfare, mutual assured destruction or as doomsday devices.

[4] In Russia, the triple "taiga" nuclear salvo test, as part of the preliminary March 1971 Pechora–Kama Canal project, produced relatively high amounts of cobalt-60 (60Co or Co-60) from the steel that surrounded the taiga devices, with this fusion-generated neutron activation product being responsible for about half of the gamma dose in 2011 at the test site.

The high percentage contribution is largely because the devices primarily used fusion rather than fission reactions, so the quantity of gamma-emitting caesium-137 fallout was comparatively low.

[7][8][9][10] The document states the torpedo would create "wide areas of radioactive contamination, rendering them unusable for military, economic or other activity for a long time."

[14] Complete 100% conversion into Co-60 is unlikely; a 1957 British experiment at Maralinga showed that Co-59's neutron absorption ability was much lower than predicted, resulting in a very limited formation of Co-60 isotope in practice.

[16] For the type of radiation given by a cobalt bomb, the dosage measured in sievert (Sv) and gray (Gy) can be treated as equivalent.

It may be possible to decontaminate relatively small areas contaminated by a cobalt bomb with equipment such as excavators and bulldozers covered with lead glass, similar to those employed at the cleanup of the Semipalatinsk Test Site.

[20] By skimming off the thin layer of fallout on the topsoil and burying it in the likes of a deep trench along with isolating it from ground water sources, the gamma air dose is cut by orders of magnitude.

[21][22] The decontamination after the Goiânia accident in Brazil in 1987 and the possibility of a "dirty bomb" with Co-60, which has similarities with the environment that one would be faced with after a nuclear yielding cobalt bomb's fallout had settled, has prompted the invention of "sequestration coatings" and cheap liquid phase sorbents for Co-60 that would further aid in decontamination, including that of water.