Consideration of methods to determine an enrichment of commercial fast reactor fuel

Maruyama, Shuhei   ; Oki, Shigeo ; Okubo, Tsutomu

In the situation that a variety of fuel composition is fed to FBRs during LWR-to-FBR transition stage, a special consideration on fuel reactivity and its loss by burnup is needed for each feeding fuel to keep criticality during operation period as prescribed. Suitable methods of determination of fuel enrichment will accomplish this without changing a pattern of fuel-loading (including number of loading fuel assembly). The choice of the method of enrichment determination affects the core characteristics which have to be controlled in core design. This paper describes some characteristics of the methods to determine an enrichment of fast reactor fuel from the core design points of view. Merits and demerits of these methods had been clarified in this study.