Study on the recently proposed direct S-CO2 and helium-cooled GCFR: Size of vessel, power conversion, and reactivity coefficients

This article contains a review on the history, progress, and objectives of the GCFR as well as a review on the newly proposed TID-type and block-type fuels of a GCFR, together with a research on their selected physical parameters. We have roughly estimated and compared size of core vessel of a suggested GCFR for S-CO2 and helium cooled as well as power conversion system efficiencies for a direct super-critical CO2 cooled cores. Moreover, the Coolant Void Reactivity (CVR) and Doppler coefficient for a reference GCFR with two different coolant types (supercritical CO2 and helium) and either different matrix materials (blended: fuel + diluents) in the block type core is calculated. MCNP 5.0 was used for our neutronic simulation and MAKXSF module was used to Doppler broaden the cross sections. Finally, the burn up comparison for two coolants and also for suggested diluents is also performed herein.