Am-241

Am-241 is isotope of Americium.

Using

$ \rm ^{241}_{~94}Pu \xrightarrow[15~y]{\beta^-,~ 21\,KeV} {} ^{241}_{~95}Am \xrightarrow[432.7\,y]{\alpha,\, 4.959\,MeV} {}^{237}_{~96}Np \xrightarrow[2.4 \times 10^6\,y]{\alpha,~4.958 \,MeV} \mathrm{^{233}_{91}Pa} ~.\,.\,. $

Am-241 is considered as the important component of the nucuear waste and dominant contaminante since come tens or years after a nuclear catastrophe.