An experimental study of the tube bundle effect on heat removal capabilities in complete condensation mode of a passive condenser was performed A full scale test section, with four condenser tubes, was designed and constructed to simulate operating conditions of a passive containment cooling system For complete condensation analysis, pure steam was supplied to the test section and heat transfer properties were measured for pressure from 100 to 280 kPa. The condensation heat transfer results were similar to the findings from single tubes, except for a slightly higher condensate mass flux. This was determined to be a result Of turbulent mixing in the secondary boiling water caused by the tube bundle. (C) 2009 Elsevier Ltd. All rights reserved