UPS is the second uranium-based pnictochalcogenide where electron-assisted tunneling presumably is realized. Although the unusual properties of UPS and UAsSe originate from the structural disorder, a clear-cut uniformity in their electrical resistivity is observed. The additional resistivity due to non-magnetic Kondo-like scattering was found as large as 140 \mu \Omega  cm at low temperatures. The estimated concentration of the fast TLS centers varies between 10¹⁹ and 10²⁰cm^-3.

PACS numbers: 72.15.Qm, 72.15.--v, 75.50.Cc