Effects of self-irradiation on local crystal structure and 5$f$ localization in PuCoGa$_5$

X-ray absorption fine-structure (XAFS) measurements demonstrate the structural and electronic changes involved in destroying superconductivity in PuCoGa$_5$ due to self-irradiation damage. In particular, the Pu $L_\textrm{III}$-edge data indicate a more localized $f$-orbital relative to the itinerant paramagnet UCoGa$_5$, potentially increasing with radiation damage. Moreover, the local crystal structure in aged material is disordered much more strongly than expected, consistent with all atoms within a damage cascade displaced from their equilibrium positions.