Burnup characteristics of thorium-uranium 233 fuel loaded in an advanced thermal reactor

Uranium 233 has a large η-value in the range of thermal neutron energy. To make use of this large η-value, authors propose to load a thorium-uranium 233 fuel in an advanced thermal reactor (ATR) and examine the burn characteristics using the SRAC code system. Achievable burnup, average conversion ratio, fissile conservation ratio and temperature coefficient are evaluated for various values of uranium 233 enrichment and moderator/fuel volume ratio (Vm/Vf). It is shown that for a given burnup value thorium-uranium 233 fuel attains higher conversion ratio than an uranium 235-uranium 238 one. An optimized composition of the thorium-uranium 233 fuel in ATR is also reported. (author)