Post by samchiu2000 on May 10, 2017 15:32:46 GMT
According to
https ://en. wikipedia. org/wiki/Cobalt_bomb
"Theoretically, a device containing 510 tons of Co-60 can spread 1 g of the material to each square km of the Earth's surface (510,000,000 km2). Radiation output from 1 g of Co-60 over one half life is equivalent to 44,000 GBq, which is sufficient to kill any inhabitants. If one assumes that all of the material is converted to Co-60 at 100 percent efficiency and if it is spread evenly across the Earth's surface, it is possible for a single bomb to kill every person on Earth. However, in fact, complete 100% conversion into Co-60 is unlikely, as 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."
So you would neeed 510 tons of Co60 equally dispersed on the entire surface.
You would actually need more cobalt than that as not all of it would be transmuted. Someone may find better sources on the "how much", but I would guess there were not enough tests to give a really precise answer (and if there were, it would be classified).
And then there is the problem of dispersing fallout.
Counter-intuitively, ground bursts seem to cause more fallout in classical nukes, though long-duration cobalt may still find its way back from atmosphere in airburst as well after a time.
Multiple small bombs may be more efficient to disperse fallout on a larger area, but covering the entire planet seems difficult.
Maybe there is also a "Project Pluto" version possible, with cruise missiles with open-core nuclear jets leaving a trail of Co60 (and varied other fallout) behind on their wake.
If you find alternate ways to seed the atmosphere (say, dropping it from space), you also have to take air currents into account. Maybe also sea currents. Do you want to seed the oceans as well? Is there a soluble cobalt compound? Is there one that would go through the entire water cycle so it can rain back on continents?
