Early Response of Hot Water to Sudden Release from High Pressure

Abstract

The very early stages of blowdown are observed with the aid of a novel quick-opening mechanism. Water at pressures and temperatures up to PWR conditions is released from a long, one-half in. (1.27 cm) ID pipe. Depressurization rates up to 1.62 × 106 atm/s are achieved. As a consequence of the rapidity of depressurization, the water reaches pressures far below saturation (even approaching the spinodal line) before nucleation occurs. The performance of the opening device is described quantitatively, and implications of the response of the water are discussed in relation to nuclear safety problems.