Simin Janitabar Darzi - Nuclear Science & Technology Research Institute, Materials and Nuclear Fuel Research School, End of North Karegar Ave., Tehran, Iran
Nilufar Mohseni - Nuclear Science & Technology Research Institute, Materials and Nuclear Fuel Research School, End of North Karegar Ave., Tehran, Iran

In the last two decades extensive R&D has been carried out on the thorium fuel cycle in nuclear industries, because of decrease of accessible uranium resources. In this research, ThO2 ceramic was synthesized by pluronic copolymer Octyl phenol ethoxylate as a directing agent .prepared ThO2-S composed of micro and meso pores and exhibited high surface area as 31.23 m2/g and particle size as 15.1 nm. The produced powder ThO2-S was pressed and sintered to form the high density ThO2 and pellets. The final grain size of the pellets reached below micrometer size. The calculated green and sintered densities of the fabricated pellets, and their microstructural characteristics studies, utilizing SEM images, show that this synthesizing route yielded a good sinterability of the synthesized ThO2 nanopowder at low temperature. Prepared ThO2-S sample and commercial ThO2 were sintered under the atmospheres Ar and Ar-8%H2, and comparison of data from samples sintered under the both of two different atmospheres at 1500 °C, show that the atmosphere had no effect on density value. Furthermore, the green density of ThO2-S pellets is less than ThO2-S but the pellets which were fabricated from the ThO2-S have reached better sintered density than the pellets fabricated by ThO2-C .

ThO2; Sol gel Process; Fuel pellet; porous ceramic; sinterability