For the ISOL-based radioactive ion beam facility, TRIAC, separation efficiencies and release times of neutron-rich isotopes produced in proton-induced fission of 238 U have been measured using the JAEA-ISOL target/ion source systems. With a FEBIAD-B2 type integrated target–ion source, for example, we obtained separation yields, the values were normalized to a uranium target thickness of 1g/cm 2 and 1μA primary proton beam current, 1.4×10 6 pps for 91 Kr, 7×10 5 pps for 126 In, 2.6×10 6 pps for 138 Xe, respectively. Using a surface ionization type ion source, under the same normalization, the separation yields of 1.8×10 7 pps for 93 Rb, 6×10 7 pps for 94 Sr, 2.5×10 6 pps for 143 Cs and 5×10 6 pps for 142 Ba were observed. The release times of radioactive Rb, Cs, Ba, In, Kr and Xe atoms were measured using present target/ion source systems. Comparison of the measured yields of Ba, In and Xe isotopes with the calculated ones suggests that the long release time gave low separation efficiency for short-lived isotopes.