Reactor Physics and Thermal Hydraulic Analysis of Annular Fuel Rod Cluster for Advanced Heavy Water Reactor

Internally and externally cooled annular fuel rod is an advantage over solid fuel rod in reactor core design in order to improve core power density and safety aspects like Minimum Critical Heat Flux Ratio (MCHFR) and lower centerline temperature. Various cluster geometries with annular fuel rod have been suggested for Advanced Heavy Water Reactor (AHWR) depending upon the operating parameters. We had already presented the design of 33 rod annular fuel cluster for AHWR in previous paper. The 33 pin fuel cluster had a lower MCHFR and the reactor power could be increased by about 20% only. The fuel bundle geometry presented in this paper is an improvised to obtain larger MCHFR and better physics performance. The AHWR uses a fuel cluster of 54 solid fuel rods and is designed for 920MWth. We have designed an annual fuel cluster with 19 fuel rods which meets all the thermal design margin as well as gives 30% more power than the solid fuel rod cluster without any considerable changes in design basis. Reactor core power calculations are carried out and then optimized burn up is obtained. This research article mainly deals with the improvements made in the annular fuel rod bundle to get optimized burn up and core power distribution.