Transmutation of technetium in the experimental fast reactor "JOYO"

Aoyama, Takafumi ; Maeda, Shigetaka   ; Maeda, Yukimoto; Suzuki, Soju

The present study examines the potential for the demonstration of fission product transmutation in the experimental fast reactor JOYO at JNC's Oarai Engineering Center. The possibility of creating a highly-efficient transmutation irradiation field by loading neutron moderating subassemblies in the reflector region of JOYO was examined in a series of scoping calculations. A cluster of reflector subassemblies was replaced with beryllium or zirconium hydride (ZrH1.65) moderated subassemblies. These moderated subassemblies surrounded one central test subassembly that would contain Tc or I target material. The Tc transmutation rate was 16.2% using ZrH and 13.9% using beryllium as moderator. As a result of this study, basic characteristics of LLFP transmutation in JOYO using relevant moderator materials were investigated and the future feasibility was shown.