THE EFFECTS OF RADIATION-DAMAGE ON THE PROPERTIES OF GRAPHNOL N3M

GraphNOL N3M (N3M) is a bulk graphite developed at Oak Ridge National Laboratory (ORNL) for advanced structural applications in aerospace thermal protection systems. It is currently of interest to the United States fusion energy community for plasma facing components, such as the first wall armor tiles of the International Thermonuclear Experimental Reactor (ITER) because of its superior thermal shock resistance and irradiation lifetime. This paper reports the results of irradiation experiments on N3M graphite at two temperatures, 600 and 875-degrees-C in the High Flux Isotope Reactor (HFIR) at ORNL. Maximum fluences of 4.2 x 10(26) and 2 x 10(26) n/m2 (E > 50 keV) or 28.4 and 13.5 dpa (graphite) were attained at 600 and 875-degrees-C, respectively. Data are presented on the dimensional stability, volume change, strength, Young's modulus, critical stress intensity factor K(Ic), and coefficient of thermal expansion (CTE). The thermal shock resistance of GraphNOL N3M is discussed and comparisons made with other graphites. The influence of irradiation damage on thermal shock resistance is postulated.