Influence of the power density on a conversion ratio in Accelerated Driven System (ADS)

The U-233 Conversion Ratio (CR) calculation results for Yalina Thermal assembly are presented as a function of burnup, power density, irradiation history and U-233 concentration. The Yalina Thermal assembly is an ADS which makes configuration changes possible. These various configurations enable investigation and comparison of CR in a Thorium cycle (Th cycle) and a mixed Uranium–Thorium cycle (U–Th cycle) of burning.The power density has no influence on the U-233 concentration dependence of CR and on the burnup dependence of CR. The calculations were done with a MCNPX code.

► The U-233 concentration dependence of conversion ratio does not depend from power density of reactor.
► The burnup dependence of conversion ratio does not depend from power density of reactor (omitting power on effects).
► The conversion ratio depends mainly from U-233 concentration (for fixed moderator to fuel ratio).
► High level of Pa-233 concentration does not decrease the conversion ratio during high power density of reactor.