STARTUP OF MODIFIED CANDLE BURNUP SCHEME IN A HELIUM COOLED FAST REACTOR USING URANIUMPLUTONIUM NITRIDE

• Main Author: SISWANDI SYAHPUTRA (NIM : 20212047); Pembimbing (Prof. Dr.Eng. Zaki Su'ud, TRI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/19588
• Institution: Institut Teknologi Bandung

Study of desain strategy startup Helium Cooled Fast Reactor with natural uranium and mixer plutonium from spent fuel PWR has been done. The reactors can be <br /> <br /> <br /> <br /> <br /> operated without refueling for 10 years middle reactor and long live reactor. Calculation has been done by using SRAC system code and JENDL-32 library, with cylindrical cell two dimensional R-Z core models. Reactor design optimization is evaluated to utilize natural uranium as reactor fuel. Optimization evaluated by burning natural uranium for 80 years and put each of its burnup result per 2 year, with scheme modified CANDLE (Constan Axial shape of Neutron flux, nuclide densities and power shape During Life of Energy producing reactor). In Modified CANDLE burn-up scheme strategy, the active core is subdivided into ten regions (region-1 until region-10) with the same volume in the axial direction and 2 region in the radial direction. The fresh fuel such as natural Uranium is initially put in region-1 and another region filled mixed spent fuel PWR and natural Uranium, after one cycle of 10 years of burn-up it is shifted to region-2, region-2 to region-3 until region 10 and then region-1 is filled by fresh natural Uranium fuels. Some of core (800-1000MWth) with various fuel fraction have been investigated. Calculation core reactor with variation fuel fraction 50 to 65%. Excess reactivity at beginning operation is high. Addition burnable poison Gadolinium in region 8- <br /> <br /> <br /> <br /> <br /> 10 to reduce reactivity. Reactor with a power of 900 MWth with a 50-55% fuel fraction obtained optimal design. The ratio of peak to average power density is <br /> <br /> <br /> <br /> <br /> 1,57 in radial and 2,57 in axial direction with power density 300 W/cc.