Experimental High Enthalpy Water Blowdown From a Simple Vessel Through a Bottom Outlet.

Abstract

S a f e t y s t u d i e s s i m u l a t i n g p r e s s u r i z e d w a t e r and b o i l i n g w a t e r r e a c t o r h y p o t h e t i c a l p i p i n g b r e a k s were conducted i n a 3 150 f t v e s s e l . High p r e s s u r e w a t e r blowdowns (up t o 2 1 0 0 p s i , from a bottom n o z z l e . I n t e r n a l p r e s s u r e and t e m p e r a t u r e , l i q u i d l e v e l , t h r u s t r e a c t i o n f o r c e s , weight of f l u i d i n t h e v e s s e l , v o i d f r a c t i o n of t h e f l u i d i n t h e e x i t d u c t were measured d u r i n g t h e blow- downs. Void f r a c t i o n i n c r e a s e d and mass v e l o c i t y d e c r e a s e d w i t h o r i f i c e s i z e .Anomalous subcooled p r e s s u r e b e h a v i o r was thought t o be caused by n i t r o g e n d i s s o l v e d i n t h e w a t e r . L i q u i d l e v e l d e c r e a s e d n o n l i n e a r l y w i t h t i m e , whereas mass l o s s r a t e was n e a r l y c o n s t a n t f o r most of t h e blowdown. Comparisons w i t h t h e o r e t i c a l t r e a t m e n t s showed t h e need f o r e m p i r i c a l c o e f f i c i e n t s t o a d j u s t p r e d i c t i o n s t o t h eobserved r e s u l t s .iii CONTENTS

Prediction of reactor coolant blowdown by similitude theory

“…Weight ratio versus pressure ratio(2) investigations(20).Figures 9 and 10, in a sense, represent an equation of state for the fluid remaining in the vessel during blowdown. The data points of the model are in agreement with the pressure predicted by a liquid blowdown, and the data of the prototype are close to the pressure predictions made by a mixture blowdown (20).…”

“…Experiment(2) which was adopted as the prototype.2. Run blowdown tests of the model to measure coolant flowrate anddecompression rate in the vessel, and predict these quantities for a reactor system by the similitude theory.3.…”