To know the characteristic of the sponge ball separator of RSG-GAS heat exchanger mechanical cleaning system PAH 01 AT 01, the function test of the system has been done in Multi Purpose Reactor-GA Siwabessy in Serpong. The commisioning has done include comissioning procedure preperation of the sponge ball separator of RSG-GAS heat exchanger mechanical cleaning system PAH 01 AT 01 and sponge ball captures capability. From the captured has done the result found 45 pl~aces of 50 peaces of sponge balls inserted. By comparing of the separation result with the minimum allowable separation limits, the characteristic of the sponge balls separator of RSG-GAS heat exchanger mechanical cleaning system PAH 01 AT 01 is accordance with the design criteria.Djaruddin Hasibuan, Aep Saepudin C, Santosa Pujiarta, Makmuri PRSG-BATAN, Kawasan PUSPIPTEK, Serpong, Tangerang. Key word: comissioning, sponge ball.
