ABSTRACT
This chapter summarizes the results of data acquisition activities and analytical evaluations performed at Three Mile Island and at several Department of Energy laboratories. The current understanding of the relocation of molten core materials into the lower reactor vessel internals and possible damage to the reactor vessel lower head are discussed in some detail. The objective of the fission product inventory is to determine the location and amounts of fission products in the plant, including those that remained in the reactor coolant system, the containment, and the auxiliary and fuel handling building. The large majority of the radionuclides released from the reactor vessel was retained in the containment building with little being transported to the auxiliary and fuel handling building or the environment. Additional samples of the lower reactor vessel head region also need to be obtained to better calculate the fission product inventory present there.
