Are you actually thinking of "Curium", which may have an atomic number 2 higher than plutonium but is not produced by bombarding Pu with He, but instead with intense neutron flux or via other decay paths (see
https://en.wikipedia.org/wiki/Curium#Synthesis ). Some isotopes certainly are quite radioactive.
I think "Cirium" is a made-up vaguely Latin sounding name so it seems erudite, like many other brand names.