Dephosphorylates pseudouridine 5'-phosphate, a potential intermediate in rRNA degradation. Pseudouridine is then excreted intact in urine. H2O + psi-UMP = phosphate + pseudouridine Inhibited by low concentrations of calcium. Belongs to the HAD-like hydrolase superfamily. CbbY/CbbZ/Gph/YieH family. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.