A requalification program was established for the Three Mile Island Unit 2 (TMI-2) reactor operators after the March 1979 accident made the TMI-2 reactor inoperable. A series of subcritical/critical experiments was presented in this requalification program using the Penn State Breazeale Reactor. The first five experiments were designed to demonstrate various conditions that might occur in the pressure vessel during the defueling program. Later this requalification program was reduced to presenting two experiments of a similar nature, but having different objectives and methods of presentation. These experiments are presented in detail, showing how this program contributed to the training of the TMI-2 operators and their successful removal of the damaged core from the TMI-2 pressure vessel.