ANP PROJECT QUARTERLY PROGRESS REPORT I t h a s been n e c e s s a r y t o s t u d y t h e b i n a r y and t e r n a r y s y s t e m s o f z i r co nium f l u o r i d e w i t h t h e a l k a l i f l u o r i d e s . Work on t h e s e u r a n i u m - f r e e m a t e r i a l s is reported under "Coolant D e v e l o p m e n t " i n t h e f o l l o w i n g . Add i t i o n o f s m a l l a m o u n t s ( 1 t o 5 mole %) o f uranium f l u o r i d e t o s e v e r a l o f t h e s y s t e m s h a s b e e n shown t o a f f e c t t h e m e l t i n g p o i n t s o n l y s l i g h t l y , and i t a p p e a r s l i k e l y t h a t any o f t h e lowm e l t i n g c o o l a n t s o b t a i n e d from t h e p r e l i m i n a r y s t u d i e s c a n be r e a d i l y converted to fuels. The a v a i l a b l e d a t a on z i r c o n i u m f u e l s a r e r e p o r t e d under appropriate headings i n the following, along with a d d i t i o n a l d a t a o n s e v e r a l systems c o n t a i n i n g beryllium fluoride.
NaF-BeF,-UF,. D i f f i c u l t y i n establishing reproducible melting points by t h e r m a l a n a l y s i s o f m i x t u r e s o f high beryllium fluoride concentration h a s been d i s c u s s e d . ( 2 ) I n an e f f o r t t o overcome t h i s d i f f i c u l t y , h e a t i n g c u r v e s h a v e b e e n compared w i t h c o o l i n g c u r v e s f o r a number o f c o m p o s i t i o n s i n t h i s system. S e l e c t e d m i x t u r e s were h e a t e d t o 850 t o 900째C and c o o l e d , w i t h s t i r r i n g , by t e c h n i q u e s p r e v i ously described, The s o l i d i f i e d m a t e r i a l s were t h e n r e h e a t e d and t h e h e a t i n g c u r v e , measured w i t h chromela l u m e l t h e r m o c o u p l e s , was r e c o r d e d i n t h e manner p r e v i o u s l y d e s c r i b e d . T h e d a t a shown i n T a b l e 2 1 a f f o r d a comparison between b r e a k t e m p e r a t u r e s
TABLE 21 Comparison of Break Temperatures from Heating and Cooling Curves O f the System NaF-BeF2-UF4 COMPOSITION ( m o 1 e %)
BREAK TEMP' .ATURE*
(OC)
ON COOLING
NaF
BeFZ
48
52
0
345, 375, 380
332**
47.5
51.5
1
330, 365, 385
350**
47
51
2
365, 385
340**
46. 5
50. 5
3
245, 315, 369, 385
355**
46
50
4
295, 325, 385
342. *
45.5
49.5
5
270, 360, 395
352**
40
60
0
230, 300, 330, 365
250, 390
39.6
59.4
1
290, 330, 355
270, 415
39.2
58.8
2
325, 355
295, 445
38.8
58.2
3
325, 370, 400, 405
315,
38.4
57.6
4
325, 365
285, 290, 315
38.0
57.0
5
330, 360
317
UF 4
ON HEATING
H i g h e s t b r e a k temperature c o n s i d e r e d m o s t r e l i a b l e i n d i c a t i o n o f m e l t i n g point.
** S u p e r c o o l i n g definitely indicated.
100
**
430