Flashing Hammer Phenomenon in Rapid Liquid-liquid Contact

Abstract

In a wall-crack accident or loss-of-coolant accident (LOCA) in an advanced reactor with water-filled containment, high-pressure saturated water is discharged from the pressure vessel into the low-pressure, low-temperature water of the containment. The discharged saturated water causes flashing and generates steam. Steam is then condensed by the water in the containment. Our previous study of high-pressure saturated water that rapidly contacts low-pressure, low-temperature water, revealed that flashing of high-pressure saturated water and a subsequent water hammer occurred under the specified experimental settings. Pressure peaked when steam generation or flashing occurred at the wall surface and the flashing steam condensed. After the peak, pressure oscillated and reached equilibrium condition in a short time. To check the results of the experiments, numerical analysis was conducted using bubble growth theory in this study.