الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The use of thorium as a fertile material in nuclear fuel has been of interest since the dawn of nuclear power technology due to the abundance of thorium ore and to the potential for some important neutronic advantages. The absorption of a neutron in 232Th produces 233U which has a high tendency to generate neutrons by fission in thermal and epithermal neutron fluxes. The first cycle of a typical PWR core (AP-1000) in which some fuel assemblies (rods) are 232ThO2 (about 40% from total fuel) for 233U production while the rest of the fuel assemblies (rods) uses low enriched uranium fuel UO2 in two different configurations, namely the Whole Assembly Seed and Blanket (WASB) and the Seed-Blanket Unit (SBU) is simulated. The Monte Carlo code MCNPX 2.7.0 was adopted to simulate the neutronic aspects of the nuclear fuel. This study compares between the effects of the use of ADS and the increase in uranium enrichment to compensate for the sub-criticality produced by the addition of thorium fuel in this core. It was found that the ADS can be used with thorium for energy production while enhancing the fertile-to-fissile conversion as well as the transmutation of long-lived radioisotopes. It was also found that the best location of thorium is in the periphery of the reactor core in the absence of ADS. But with ADS, the thorium can be distributed with uranium inside the reactor core which resulted in the largest increase in the percentage composition of U- 233.