VAPOR SUPPRESSION TEST PROGRAM REPORT

The Vapor Suppression Test Program conducted under the NS Savannah Upgrading Program demonstrated that the containment of a reactor and its primary system will operate under water, and that a water-filled containment has definite advantages over a standard dry containment. A test facility was constructed to obtain information on condensation, shock formation, and impact forces resulting from an under water pipe rupture. Forty-six rupture tests were conducted with 1- , 2-, 3-, and 6-inch-diameter ruptures. Primary system pressures ranged from 500 to 1950 psig, and temperature ranged from ambient to 600 deg F. Complete condensation was obtained in all rupture tests with horizontal discharge. In the 1-inch rupture tests with the discharge directed vertically upward, condensation was complete with two feet of water above the rupture. The shock pressures generated in the containment water are small. The shock pressure front was not steep-fronted, but sinusoidal shaped. A theoretical method for predicting the magnitude of the maximum overpressure was developed and compares favorably with test results. The maximum shock pressure recorded from a 6-inch rupture in a system operating at 1750 psig and 500 deg F was 68 psig. The duration of the 68 psig pulse was <0.5 msec. The maximummore » pressure of any significant duration was 40 psig at 43 inches from the rupture. The impact force of the effluent discharging from the rupture is sharply attenuated with distance owing to the wide divergence of the jet. The initial angle of divergence is about 120 degrees, and the axial penetration is less than eight rupture diameters. The maximum recorded impact pressure (147 psig) occurred at a distance of 12 inches from a 3-inch diameter rupture in a system operating at 1750 psig and 510 deg F. The pressure lasted for about 50 msec, followed by pulsations of lesser magnitude. (auth)« less