STUDIES OF UPPER-PLENUM COOLANT CIRCULATION IN A QUARTER-SCALE AIR-FLOW MODEL OF THE PWR

Air-flow studies were run in a quarter-scale flow model of the PWR to determine distribution of flow throughout the upper-plenum region with two different hold-down-barrel designs. With each hold-down barrel, flow paths were determined for operation with four loops, three loops, two opposed loops, and two adjacent loops. Exploration of flow patterns and velocities throughout the upper plenum showed that circulation of coolant throughout the upper plenum was satisfactory with either of the hold-down barrels investigated. (auth