[en] KAERI has performed a series of steam condensation tests to assess the performance of a unit cell sparger that will be used in the APR1400 reactor. A simplified I-sparger with a bottom hole was used for the steady-state steam condensation tests to study the characteristics of the condensation phenomena in a multihole sparger. Ranges of steam mass fluxes and pool temperatures for the condensation tests were selected to study the effect of a bottom hole on the overall steam condensation phenomena in a unit cell tank. General trends of the condensation loads and the variations in the frequencies of the pressure waves due to steam condensation in a multihole sparger with a bottom hole are presented. The test data is compared with that of previous condensation tests that used a sparger without a bottom hole and the results show that a sparger with a bottom hole significantly reduces the magnitude of the condensation loads. (author)