T.S. Syahputra, Abdul Razak, Zaki Su'ud
The startup strategies for neutronic analysis Gas-Cooled Fast Reactors with scheme Modified CANDLE have been investigated. This research used natural uranium and spent fuel PWR in the starter core. The reactor power level was set at case 800 MWth, 900 MWth, and 1000 MWth, while the fuel fraction was varied at 50%, 55%, 60%, and 65%. The calculation was performed by using SRAC-CITATION system codes, with two-dimensional R-Z cylindrical cell models. In this Modified CANDLE burnup scheme start-up strategy, the active core was divided into ten regions (region-1 until region-10) with similar volume in the axial direction and two regions in the radial direction. The fresh fuel of natural Uranium was initially put in region-1 while another was filled with a mixture of spent fuel PWR and natural Uranium. After each cycle of burnup, defined by 10 years, the fuel from region-1 was shifted to region-2, and the fuel from region-2 was shifted to region-3. This was done consecutively until all the regions have been refueling while region 1 is refilled with natural uranium fuel. An optimum design was achieved in the reactor by 60% inner and 65% outer fuel fraction for case 800 MWt. The ratios of a peak to average power density were 1.37, with power density of 187.43 W/cc. © 2020 Published under licence by IOP Publishing Ltd.
Departement of Physics, Institut Teknologi Sumatera, Lampung, Indonesia; Nuclear and Biophysics Research Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Indonesia