Microscopy and Microanalysis | 2019
Evolution of Materials Properties and Macropores in Thermally Crept Nuclear Graphite
Graphite is an important component to the design of high-temperature gas-cooled reactors. Many of these reactors use graphite as a neutron moderator and/or structural component such as fueland gascoolant channels , , . Graphite is a desirable material because of its low neutron absorption cross-section and its high-temperature strength . During operation, material properties and dimensions can change as a function of neutron irradiation dose and temperature. Gradients in both temperature and dose can lead to significant stress and distortion of the graphite components. Over time these stresses and distortions, if unaccounted for, can lead to failure of components, blockage of coolant channels, and even restriction of control rod sleeves .