Results of recent TMI-2 distinct core component examinations

The US Dept. of Energy is sponsoring a Three Mile Island Unit 2 (TMI-2) accident evaluation program that is being conducted by EG and G Idaho, Inc., at the Idaho National Engineering Lab. One part of this program is examination of distinct core components, which is the subject of this paper. The TMI-2 distinct core component examination program focuses on core components with high potential for yielding information about the behavior of core materials and fission products. Nondestructive examinations including photography, neutron radiography, gamma spectroscopy scanning, and density and particle-size determinations were performed. The results of these examinations were invaluable in selecting components for destructive examinations. The destructive examinations include metallography with scanning electron microscopy, chemical analysis of core element abundance, and radiochemical analysis for fission products. The examination results discussed in this paper are related to the following components: (1) fuel assembly upper end fittings, (2) fuel rod upper and lower ends, and (3) control and burnable poison rod upper and lower ends.