İNERMA, 1 - 03 October 2015
Thorium (232Th) is a naturally-occurring metal and is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium. Although thorium is not itself fissile which makes it unusable in thermal reactors directly, the use of thorium was considered as an option for the fuel of nuclear reactors since the birth of nuclear energy due to its abundance, high melting point, high thermal conductivity, high chemical stability, and high fission product retention in ThO2 matrix. Besides these superior physical properties, it has certain advantages in terms of reactor operation such as it transforms to a best fissile isotope for thermal reactors (233U), higher burnups can be achieved, and it has less chemical reactivity with water at vapor, and radiotoxic inventory of ultimate waste from thorium cycles decreases much sooner than the one of U/Pu cycles. Although thorium cycle presents real attractive features, there are a lot of challenges to be overcome in the stage of fuel fabrication, reprocessing, design of new thorium/fissile material fuel cycles, etc. This article discusses future of thorium as a nuclear fuel considering advantages and drawbacks from the beginning to end of nuclear fuel cycle.