The results through 1988 of the postaccident inventory and distribution of selected radionuclides within the Three Mile Island Unit 2 (TMI-2) reactor system are presented. Best-estimate inventories are presented for krypton (85Kr), cesium (137Cs), iodine (129I), antimony (125Sb), strontium (90Sr), ruthenium (106Ru), and cerium (144Ce). This inventory accounting includes all repositories in the TMI-2 reactor system. The accountability for principal radionuclides includes 144Ce (105%), 90Sr (93%), 137Cs (95%), and 85Kr (91 %). The accountability for radioiodine is similar to that for cesium. The principal repositories for cesium and iodine, and the noble gases, are the reactor building, and the reactor vessel for all other radionuclides.