Cobalt bomb

A cobalt bomb is a theoretical type of "salted bomb": a nuclear weapon designed to produce enhanced amounts of radioactive fallout, intended to contaminate a large area with radioactive material. The concept of a cobalt bomb was originally described in a radio program by physicist Leó Szilárd on February 26, 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, a doomsday device. Such "salted" weapons were requested by the U.S. Air Force and seriously investigated, but not deployed. In the 1964 edition of the DOD/AEC book The Effects of Nuclear Weapons, a new section titled radiological warfare clarified the "Doomsday device" issue.

As far as is publicly known, no cobalt bombs have ever been built. The Operation Antler/Round 1 test by the British at the Tadje site in the Maralinga range in Australia on September 14, 1957 tested a bomb using cobalt pellets as a radiochemical tracer for estimating yield. This was considered a failure and the experiment was not repeated. Furthermore the triple "taiga" nuclear salvo test, as part of the preliminary March 1971 Pechora–Kama Canal project, produced substantial amounts of Co-60 from steel tubes and soil ("Origin of Co-60. Activation of stable Co, Fe, Ni (from the explosive device and the steel pipe, and from soil) by neutrons"), with this fusion generated neutron activation product being responsible for about half of the gamma dose now (2011) at the test site, with photosynthesizing vegetation existing all around the lake that was formed.