Experimental study on dilution coefficients measurement of capsule dilution tube for fuel transient tests

Inoue, Shuichi ; Omuro, Tadao; Nabeya, Hideaki; Matsui, Yoshinori ; Iida, Kazuhiro; Ito, Kazuyuki; Kimura, Akihiro ; Kanno, Masaru

In fuel irradiation transient tests using a boiling water capsule, a dilution tube has been installed in the boiling water capsule in order to detect fission products (FP) from an irradiated fuel, in case of the fuel failure during the transient, by a radiation monitor located outside the reactor. When the fuel failure occurs, the released FP flows out from the capsule through the dilution tube. The dilution tube is designed to minimize the released FP that can be detected by the radiation monitor located outside the reactor. This report summarized the measurement results of the dilution tube installed in the boiling water capsule.