ANP PROJECT QUARTERLY PROGRESS REPORT n e a r l y z e r o p o r o s i t y a n d would c o n t a i n a minimumof 7 5 m o l e % b e r y l l i u m o x i d e . The g l a s s f o r m i n g t h e bond would a l s o c o n t a i n a s m a l l amount o f b e r y l l i u m oxide, c o n s i s t e n t w i t h v i s c o s i t y requirements for fabrication. Simulated mixes u s i n g s o d a - l i m e - s i l i c a g l a s s and s i l i c a s a n d were p r e p a r e d on a s m a l l s c a l e , and i t w a s d e t e r m i n e d t h a t s u c h a m a t e r i a l c o u l d be made s u c c e s s f u l l y , The d e n s i t y o f a s e l e c t e d , g l a s s - b o n d e d beryllium oxide, reflector-moderator m a t e r i a l w a s determined a s 2.6 g / c c . I t i s proposed t h a t t h e r e f l e c t o r be c o o l e d by m e t a l p i p e s e m b e d d e d i n t h e
1 2 . HEAT TRANSFER AN
glass-bonded beryllium oxide. The p i p e s would c o n t a i n f l o w i n g sodium a s a c o o l a n t , and once t h e g l a s s - b o n d e d b e r y l l i u m o x i d e had heen poiired i n t o t h e s h e l l and had flowed around t h e c o o l i n g p i p e s , t h e r e a c t o r s h e l l would n o t be a l l o w e d t o c o o l b e l o w a t e m p e r a t u r e j u s t above t h e annealing range o f t h e g l a s s bond. F u r t h e r r e f i n e m e n t s a n d e n g i n e e r i n g t e s t s w i l l be made, s h o u l d t h i s m a t e r i a l he o f i n t e r e s t . h o n g t h e s e would be t h e d e t e r m i n a t i o n of t h e d e v i t r i f i c a t i o n tendency o f t h e g l a s s y m a t r i x and t h e c o r r o s i o n e f f e c t of t h e g l a s s with s e l e c t e d metals.
PIIYSPCAL PROPERTIES RESEARCH
H. F . P o p p e n d i e k , R e a c t o r E x p e r i m e n t a l E n g i n e e r i n g D i v i s i o n V i s c o s i t y measurements have been made f o r two z i r c o n i u m - b e a r i n g f l u o r i d e F o r t h e p r o b a b l e ARE fuel mixtures. f u e l N a F - Z r F 4 - U F 4 ( 4 6 - 5 0 - 4 m o l e S,) t h e v i s c o s i t i e s r a n g e from 20 c e n t i p o i s e s a t a b o u t 580°C t o 7 c e n t i p o i s e s a t a b o u t 830°C, a n d f o r t h e f u e l NaFZrF4-UF, ( 5 0 - 4 6 - 4 m o l e %) t h e v i s c o s i t i e s range from 17 c e n t i p o i s e s a t a b o u t 580°C t o 6 c e n t i p o i s e s a t a b o u t 830°C. A capillary viscometer is b e i n g a s s e m b l e d and w i l l be u s e d t o obtain data t o supplement the data from t h e e x i s t i n g v i s c o m e t e r s . Some p r e l i m i n a r y t h e r m a l c o n d u c t i v i t y e x p e r i m e n t s on t h e f u e l NaF-KF-LiF-UF4 (10.9-43.5-44.5-1.1 m o l e 70) h a v e y i e l d e d t h e c o n d u c t i v i t y v a l u e 2.2 f 0.2 B t u / h r n f t 2 ( " F / f t ) over t h e tempera t u r e r a n g e 500 t o 750°C. The v a p o r p r e s s u r e s o f ZrF, a n d ZrF,,-bearing fuel mixtures a r e being determined. Zirconium t e t r a f l u o r i d e is t h e most p r e v a l e n t vapor phase above ZrF4bearing fuel t o the extent of about E n t h a l p y and h e s L 1 0 ram Hg a t 8 0 0 ° C . c a p a c i t y have been determined f o r lithium hydroxide.
144
Experimental, forced-convection, h e a t t r a n s f e r d a t a f o r molten sodium hydroxide flowing turbulently in c i r c u l a r t u b e s w e r e r e p r e s e n t e d by the equation over
t h e R e y n o l d s number
range of
6,000 t o 12,000. This equation is w i t h i n 9% o f t h e o n e n o r m a l l y u s e d t o
describe convective heat transfer of ordinary fluids. I n f o r m a t i o n on t h e r m a l e n t r a n c e l e n g t h s was a l s o d e t e r m in e d ,
Some e x p e r i m e n t a l , p o o l - b o i l i n g d a t a f o r a mercury system have been obtained for several pressure levels and two d i f f e r e n t k i n d s o f h e a t t r a n s f e r - s u r f a c e m a t e r i a 1s H e a t a n d momentum t r a n s f e r a n a l y s e s h a v e b e e n made f o r t h e ANP t h e r m a l convection harps for predicting the liquid circulation velocities. This i n f o r m a t i o n i s needed i n t h e i n t e r p r e t a t i o n of t h e harp corrosion resul-ts. I n t h e one c a s e examined, t h e c i r c u lation velocity was approximately 0.1 f t / s e c .