Development of high burn-up fuel for gas-cooled fast reactor (GFR), 2-4; Microstructure evaluation of high burn-up fuel elements

Donomae, Takako  ; Miwa, Shuhei  ; Park, J. S.*; Hinoki, Tatsuya*

Characteristics of the composite fuel assembly for the high burn-up fuel for the gas cooled fast breeder reactor were evaluated. By observing the microstructure from the viewpoint of the interface between SiC matrix in composite fuel assembly and buffer material, it became clear that there was the correlation between auxiliary segregation situation and strength characteristic. In addition, SiC matrix after the intensity test was also examined on the relation between microstructure and stress loading situation. As the result, there was the correlation in the growth agree with of existence and crystal grain of the stress loading.