Existing americium is concentrated in the areas used for the atmospheric nuclear weapons tests conducted between 1945 and 1980 , as well as at the sites of nuclear incidents , such as the Chernobyl disaster . For example , the analysis of the debris at the testing site of the first U.S. hydrogen bomb , Ivy Mike , ( 1 November 1952 , Enewetak Atoll ) , revealed high concentrations of various actinides including americium ; but due to military secrecy , this result was not published until later , in 1956 . Trinitite , the glassy residue left on the desert floor near Alamogordo , New Mexico , after the plutonium-based Trinity nuclear bomb test on 16 July 1945 , contains traces of americium-241 . Elevated levels of americium were also detected at the crash site of a US Boeing B-52 bomber aircraft , which carried four hydrogen bombs , in 1968 in Greenland
crash site
1968 Thule Air Base B-52 crash
Americium