Study of core performance for commercial Fugen; Study of burnable poison

not registered; not registered; Fukuda, Kenji*; not registered; not registered; not registered

Burnable poison in the fuel elements has been mainly used for decrease of power peak due to refueling in the Light Water Reactor. In the present study of core performance of commercial Fugen, core characteristics by introductions of Gd burnable poison was investigated from the view points of Keff, local peaking factor, mismatch factor and coolant void reactivity. The conclusions are summarized as follows. (1)Effective control or core reactivity is achieved by introduction of Gd burnable poison into a few fuel elements in inner layer. (2)Improvement of local peaking factor cannot be easily achieved by Gd burnable poison. (8)Mismatch factor is decreased from 6 % to 18 % by Gd burnable poison. (4)Coolant void reactivity shifts more negative by introduction of Gd burnable poison.