Selection Study of Am-Target Candidates for the Irradiation in Fast Reactors

Osaka, Masahiko  ; Yoshimochi, Hiroshi; Donomae, Takako ; Inoue, Masaki 

Selection study of Am target candidates for the irradiation in the experimental fast reactor JOYO was performed by the investigation of previously reported studies as a part of JNC-JAERI joint project. Criteria of the selection of inert matrix for the Am target was decided and preliminary selection was carried out on the basis of the investigation results of the present status of development of target and several selection studies in the world. Detailed investigation of the properties such as thermal conductivity, irradiation behavior,fabrication technique on seven pre-selected candidates, specifically ZrO2, Al2O3, MgO, SiC, Si3N4, MgAl2O4 and TiN, was then performed. Five matrices for Am target candidates, ZrO2, MgO, SiC, Si3N4 and TiN,were consequently selected on considering the criteria,in particular, adaptability of the fabrication process were also designed and decided as follows: Dispersed type of Am oxide particle (dia:100/300 micro meter)into MgO (1) Am oxideparticle fabrication by dry route ; i.e. compacting of Am oxide powder, crushing and sieving (2) Mixing of Am oxide particle with MgO particle made by spray dry (3) Pelletizing by uni-axial press and sintering in one atm of inert atmosphere Mixed type of Am oxide (1) Mixing of Am oxide powder with material (SiC, Si3N4 or TiN) powder (2) Pelletizing by uni-axial press and sintering in one atm of inert atmosphere Fabrication test and property measurement will be conducted for the final decision of Am-containing target.