Pin power reconstruction capability has recently been added to the SIMULATE-3 nodal reactor analysis code. Detailed descriptions of the models employed are presented. This reconstruction method is based on single-assembly (not colorset) form functions, and a detailed treatment of spectral interaction between assemblies is introduced. This pin power reconstruction method produces accurate calculation of pin powers throughout depletion and fuel shuffling. Comparisons with multigroup transport calculations and with measured critical assembly power distributions demonstrate that the pin power reconstruction method is comparable in accuracy to fine-mesh methods. The high numerical efficiency of the reconstruction method permits economical calculation of three-dimensional pin power distributions in light water reactors.