ratmijypo'ijbama lujvo

x1 is an atom(ic)/nuclear (fission) bomb which operates primarily by the fission of core/isotope x2.

See also: "ratmijyzbajbama".

In notes:

ratmijyzbajbama
x1 is a thermonuclear device/atomic nuclear fusion bomb with primary core/fusing material/isotopes x2.