Participants: G. S. Was, PI, S. Teysseyre, Assistant Research Scientist
Sponsor: General Electric
This program focuses on post-test fracture surface examination of CGR samples in a scanning electron microscope (SEM) in a hot cell, in support of a larger program being conducted by General Electric for the Electric Power Research Institute. The microscope we will be using is a Philips Quanta-HiVac SEM. This instrument is ideal for hot cell applications since the vacuum and column system can be separated from the computer control. Therefore, the instrument can be moved into the hot cell when needed, while the computer control is located outside. Further, this instrument has a large specimen chamber and sample mounting system, both easing SEM use within a hot cell. The Quanta SEM uses operating voltages between 1 and 30 kV, allowing for analysis on a wide range of materials and excitation of the x-rays from all elements of interest. Energy dispersive x-ray spectrometry and a back-scatter detector will provide compositional analysis of irradiated specimens.
Each sample fracture surface will be examined to verify the straightness of the crack front and also to verify that the crack mode was indeed intergranular. Fracture surfaces will also be used to calibrate the DCPD results. The fracture mode during crack growth will be characterized in terms of the degree of intergranularity and to characterize secondary cracking. Both halves of the CT sample will be examined.