The Radiation Range was a mountain range on the planet Skaro, located on the continent of Dalazar.
Thousands of years prior to the 2060s, the Daleks discovered pure cobalt in the mountains. They used the ore to manufacture neutron bombs to help them in their war against the Thals. However, they would never be used for this purpose. Instead, the bombs accidentally detonated when a meteorite storm struck the buildings where the bombs were kept, eventually resulting in the near-extinction of the original Dalek race and the emergence of their mutated descendants. (COMIC: Genesis of Evil)