Effect of Flow Blockage on the Coolability during Reflood in a 2 × 2 Rod Bundle. (1st April 2014)

• Record Type: Journal Article
• Authors: Kim, Kihwan; Kim, Byung-Jae; Youn, Young-Jung; Choi, Hae-Seob; Moon, Sang-Ki; Song, Chul-Hwa
• Other Names: Gou Junli Academic Editor.
• Is Part Of: Science and technology of nuclear installations. Volume 2014(2014)
• Publication Date: 2014-04-01
• Subjects: Nuclear engineering -- Periodicals; Nuclear facilities -- Periodicals; Nuclear engineering; Nuclear facilities; Electronic journals; Periodicals; 621.48
• DOI: 10.1155/2014/247862
• Languages: English
• ISSNs: 1687-6075

Abstract

Abstract : During the reflood phase of a large-break loss-of-coolant accident (LBLOCA) in a pressurized-water reactor (PWR), the fuel rods can be ballooned or rearranged owing to an increase in the temperature and internal pressure of the fuel rods. In this study, an experimental study was performed to understand the thermal behavior and effect of the ballooned region on the coolability using a 2 × 2 rod bundle test facility. The electrically heated rod bundle was used and the ballooning shape of the rods was simulated by superimposing hollow sleeves, which have a 90% blockage ratio. Forced reflood tests were performed to examine the transient two-phase heat transfer behavior for different reflood rates and rod powers. The droplet behaviors were also investigated by measuring the velocity and size of droplets near the blockage region. The results showed that the heat transfer was enhanced in the downstream of the blockage region, owing to the reduced flow area of the subchannel, intensification of turbulence, and deposition of the droplet.