VAPOR-LIQUID EQUILIBRIA FOR NITRIC ACID-WATER AND .
PUCID- 18148VAPOR-LIQUID EQUILIBRIA FOR NITRIC ACID-WATER A N DPLUTONIUM NITRATE-NITRIC ACID-WATER SOLUTIONSA. MAIMONIJanuarv 1980#.This work was supported by the United States Nuclear Regulatory Commission undera Memorandum of Understandingwith the United States Department of Energy.
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fVAPOR-LIQUID EQUILIBRIA, FOR NITRIC ACID-WATER AND PLUTONIUM NITRATEN I T R I C A C I D - WATER SOLUTIONS.ABSTRACTThe l i q u i d - v a p o r e q u i l i b r i u m data f o r n i t r i c a c i d and n i t r i c acid-plutoniumn i t r a t e - w a t e r s o l u t i o n s were examined t o develop c o r r e l a t i o n s c o v e r i n g t h e rangeo f c o n d i t i o n s encountered i n n u c l e a r f u e l reprocessing.The scanty a v a i l a b l edata f o r plutonium n i t r a t e s o l u t i o n s are o f poor q u a l i t y but a l l o w an order ofmagnitude estimate t o be made.A formal thermodynamic a n a l y s i s was attemptedi n i t i a l l y but was not successful due t o t h e poor q u a l i t y o f t h e data as w e l las t o t h e complex chemical e q u i l i b r i a i n v o l v e d i n t h e n i t r i c a c i d and i n t h eplutonium n i t r a t e s o l u t i o n s .Thus, w h i l e t h e r e was no d i f f i c u l t y i n c o r r e l a t i n ga c t i v i t y c o e f f i c i e n t s f o r n i t r i c a c i d s o l u t i o n s over r e l a t i v e l y narrowtemperature ranges, attempts t o extend t h e c o r r e l a t i o n s over t h e range 25 Ct o t h e b o i l i n g p o i n t were n o t successful.The a v a i l a b l e data were t h e nanalyzed u s i n g e m p i r i c a l c o r r e l a t i o n s from which normal b o i l i n g p o i n t s andr e l a t i v e v o l a t i l i t i e s can be obtained over t h e c o n c e n t r a t i o n ranges 0 t o700 g / k Pu, 0 t o 13 M n i t r i c acid.A c t i v i t y c o e f f i c i e n t s are required,however , i f estimates o f in d i v i dual component vapor pressures are needed.r e q u i r e d t e r n a r y a c t i v i t y c o e f f i c i e n t s can be approximated from t h ec o r r e l a t i ons.DISCLAIMERThe
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CONTENTS. . . . . . . . . . . . .FOREWORD . . . . . . . . . . . . .NOMENCLATURE. . . . . . . . . . .I. INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . .ANALYSIS OF NITRIC A C I D LIQUID-VAPOR EQUILIBRIUM DATA . . . . .A. Hala's Treatment o f Vapor-Liquid E q u i l i b r i u m f o rE 1ec t r o l y t e So 1u t i ons . . . . . . . . . . . . . .B. Extension o f H a l a ' s Treatment o t Nonisothermal C o n d i t i o n s . .C.Correlation o f Relative V o l a t i l i t i e s . . . . . . . . .D. P o s s i b l e Reasons f o r t h e Lack of F i t . . . . . . . . .ABSTRACT,11.111.I V.ANALYSIS OF PLUTONIUM NITRATE SOLUTIONS LIQUID-VAPOREQUILIBRIUMDATAA. E s t i m a t i o n o f t h e Ternary I n t e r a c t i o n Constant, DB. E s t i m a t i o n o f B o i l i n g P o i n t sC. Estimate o f R e l a t i v e V o l a t i l i t y Using F u r t e r ' s Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CONCLUSIONSREFERENCES'APPENDIX 1:ESTIMATE OF VAPOR COMPOSITION AND VAPOR PRESSURESOVER THE PLUTONIUM NITRATE STORAGE TANKS AT THEREPROCESSING PLANT AT BARNWELL, S. C. . . . . . . .Viiiviiix1227151826303437414550
FOREWORD.W i l l i a m Harrison assisted i n t h e e a r l y p o r t i o n of t h i s work by applying t h eGNLS code t o the c o r r e l a t i o n o f a c t i v i t y c o e f f i c i e n t s f o r pure n i t r i c acid.vii
4
I .NOMENCLATUREaij,Ai Aijtoe f f ic ie n t sBone o f t h e e l e c t r o l y t e s i n t h e m i x t u r ebc o e f f i c i e n t t o v a r i o u s equationsCconcentration'i,D]coe f i c i e n t s f o r v a r i o u s l e a s t square f i t sEdev a t i o n f u n c t i o nImean i o n i c s t r e n g t hKequi 1 ib r i um constantkconstant f o r F u r t n e r ' s equation [Eq.(SO)]1o g a r i thm base el o g a r i t h m base 10Ni.number o f moles of component i i n s o l u t i o nNnumber of p o i n t s used i n l e a s t squares f i tPpressure, t o r r .Qa f u n c t i o n o f t h e excess f r e e energyRu n i v e r s a l gas c o n s t a n tix
Sstandard deviationTtemperature,ttemperature, "C'imole fractionsZit o r ZiOKcharge of positive (or negative) i o n of species irelative v o l a t i l i t y f o r a binary systemaa y(1-X)/(1-y)Xar e l a t i v e v o l a t i l i t y of s a l t containing solutionBH a l a ' s separation functionSactivity coefficient of component i , mole fraction scaleYiAdifference between experimental and calculated boiling temperature;average value of AAFexcess f r e e energycal cul ated increase in boi 1 i ng pointATbvit,vinumber of positive (or negative) ions obtained by ionization ofcomponent itotal number of ions of species i , vi -- vi viSubscriptstor-apply t o positive or negative ions -mean ionicSapplies t o s a l t s o l u t i o nX vi-
applies t o n i t r i c acid .applies t o plutonium ( I V ) n i t r a t eapplies t o waterSuperscript0value a t the reference s t a t exi
I.INTRODUCTIONThe f e a s i b i l i t y o f u s i n g process c o n t r o l measurements as a p a r t o f t h eM a t e r i a l C o n t r o l and M a t e r i a l Accounting measurements r e q u i r e d f o r safeguardingn u c l e a r m a t e r i a l depends on t h e development o f proper process models, whichrange from simp1 e c l o s u r e equations' t o complex dynamic e s t i m a t i o n z y 3techniques, and a f i r m data base o f p h y s i c a l p r o p e r t i e s and thermodynamic dataf o r t h e v a r i o u s process streams.While a c o n s i d e r a b l e body o f data e x i s t s , most o f i t c o n s i s t s o f compilat i o n s made when t h e b a s i c s e p a r a t i o n processes i n t h e nuclear f u e l c y c l e wereThese data were "good enough" f o r t h e j o b a t hand b u ti n i t i a l l y developed.leave much t o be d e s i r e d when used w i t h t h e models r e q u i r e d f o r safeguardsm a t e r i a l e s t i m a t i o n / m a t e r i a l l o s s detection.Knowledge of t h e v a p o r i z a t i o n behavior o f plutonium n i t r a t e s o l u t i o n si s r e q u i r e d f o r modeling t h e dynamics o f evaporation from a plutonium n i t r a t es o l u t i o n s t o r a g e tank2 and f o r p r e d i c t i n g t h e b o i l i n g p o i n t s and vaporcompositions f o r t h e modeling o f a plutonium n i t r a t e concentrator. 3I n i t i a l l y a formal thermodynamic a n a l y s i s was attempted, which would haveallowed t h e use o f t h e two independent s e t s of d a t a a v a i l a b l e f o r plutoniumn i t r a t e solutions:v a p o r - l i q u i d . e q u i 1 i b r i a a t v a r i o u s temperatures andnormal b o i l i n g p o i n t s .IThe formal thermodynamic a n a l y s i s was n o t successfuland t h e l i q u i d - v a p o r compositions data were c o r r e l a t e d u s i n g e m p i r i c a l f i t s ;however, t h e r e s u l t s of t h e formal a n a l y s i s a r e usefwl t o approximate t h ev a l u e o f t h e a c t i v i t y c o e f f i c i e n t s needed t o e s t i m a t e i n d i v i d u a l componentvapor pressures a t temperatures o t h e r t h a n t h e normal b o i l i n g p o i n t .1
The c o r r e l a t i o n of t h e few a v a i l a b l e data f o r plutonium n i t r a t e r e q u i r e sas an i n p u t t h e behavior o f t h e b i n a r y system n i t r i c acid-water.Thus, t h en i t r i c acid-water system w i l l be discussed f i r s t .11.ANALYSIS OF NITRIC ACID LIQUID-VAPOR EQUILIBRIUM DATAThe most d e t a i l e d c u r r e n t l y avai 1a b l e t r e a t m e n t of e l e c t r o l y t e s o l u t i o n swas i n i t i a t e d by P i t e r and- extended by Cruz and Renon7; however, t h es i m p l e r t h e o r e t i c a l treatment of Hala e t a1.8 was used, because i t i n i t i a l l yappeared simpler t o use and more e a s i l y extended t o mmulticomponent systems9and nonisothermal data. H a l a has shown t h a t h i s system of equations canbe used t o produce very good f i t s t o t h e experimental d a t a of e l e c t r o l y t es o l u t i o n s over wide c o n c e n t r a t i o n ranges,i s o l t h e r m a l data.i n c l u d i n g i s o b a r i c as w e l l asAlso, t h e a u t h o r ' s i n i t i a l attempt a t c o r r e l a t i n g "p l u t o n i u m n i t r a t e s o l u t i o n d a t a from t h e Reactor Handbook"satisfactory results.gave a p p a r e n t l yThe c o r r e l a t i o n seemed t o be l i m i t e d by t h e i n t r i n s i cq u a l i t y of t h e data.A.HALA'S TREATMENT OF VAPOR-LIQUID EQUILIBRIUM FOR ELECTROLYTE SOLUTIONSThe main aspects of H a l a ' s approach w i l l be reviewed i n t h e c o n t e x t ofa three.-component m i x t u r e o f two s t r o n g e l e c t r o l y t e s ,non-ionizing v o l a t i l e solvent,K.Z2 c z2 "2- C-2C, and aThe i n d i v i d u a l i o n i z a t i o n s a r e1B r vl B zl v1 Bc vB andz2-
Ifwe d e f i n ewhere t h e values o f v a r e chosen f o r t h e a p p r o p r i a t e i o n i z a t i o n e q u i l i b r i u m ,t h e ( a n a l y t i c a l ) mole f r a c t i o n s i n terms o f t h e number o f moles o f eachcomponent a r e g i v e n byN,1(5)x1 N1 N2 N3x2 N2N N N123'3-N,3(7)N1 N2 N3and t h e concentrations o f t h e i n d i v i d u a l i o n s (assuming complete i o n i z a t i o n f o r t h e a p p r o p r i a t e e q u i l i b r i a , Eqs. (1) and (2),.vlNl3are
In our case, components 1 and 2 have a common anion (NO 3 - ) and Eqs. (10) and(11) become.The mean mole f r a c t i o n s are given by)l/v2'P -'3V 2 -(x2 N,3v1 N1 v2 N2 N3The ionic strength I,I [(xv22-i s defined byv 1 z 1 2 v 1-z;-)x1 (v2 z2 v 2-z q ](16)'2The basis for Hala's approach i s his assumption t h a t the excess freeenergy of m i x i n g can be expressed as a f u n c t i o n o f a term w h i c h handlest h e electrostatic interaction of the ions and another term whichhandles the non-Coulombic interactions.The f i r s t term, Q,,-can berelated t o the ionic strength by using the series expansion:E-AF b I c13/2 d1 2 --while the second term, Qb, i s d i r e c t l y related t o concentrations.a ternary system,4For
. '2X3A23The electrostatic interaction term predominates and Hala refers totreatments using only the electrostatic term, Eq. (17), as the firstapproximation, whereas both terms are used in the second approximation.The individual mean activity coefficients can be formally derivedfrom Eqs. (17) and (18):to obtain, for a binary system (HN03-H20),using the first andsecond approximations:logy3 - 21 c x13122logy1 /v3 A B X1 C (1 - 2 X1) BSimilar, but more complex equations can be derived for ternary systems.Hala defines a separation function B , similar to the relative volatility:5
V .which becomes, f o r HN03- Hpo.solutions,and, f o r a t e r n a r y system, such as t h e HN03.-P u ( N O )- H20 s o l u t i o n s(component 2 i s nonvol a t i 1e ) .I f plutonium n i t r a t e i s assumed t o be s i n g l y i o n i z e d 3 i n t h e rangeo f c o n c e n t r a t i o n s o f HN03 o f i n t e r e s t t o us, 2.1 t o 3.8 molar,*The i o n i c s t r e n g t h i s g i v e n byII x1 x2and*The nominal c o n c e n t r a t i o n s a t t h e o u t l e t o f t h e plutonium n i t r a t e s o l u t i o nc o n c e n t r a t o r and i n t h e storage tanks a t t h e A l l i e d General Nuclear Servicesreprocessing p l a n t a t Barnwell , So. Carolina, were going t o be 250 g/a o r0.02159 mole f r a c t i o n o f Pu (N03)4 and 3.0 M. o r 0.06214 mole f r a c t i o n o fHN03.6
The dependence o f t h e s e p a r a t i o n f u n c t i o n on t h e composition o f t h el i q u i d phase are given by t h e f o l l o w i n g :f i r s t - o r d e r terms only:f ir s t- and second-order terms:Iwhere t h e values of a13, b13, and 1 are3obtained f r o m f i t t i n g t h eb i n a r y system (X2 0) and t h e value o f D i s obtained from t e r n a r ydata.The constants i n Eqs. (29) and (30) are r e l a t e d t o those i nEqs. (20) through (22) by t h e d e f i n i t i o n ofB,?,Eq. (21), i.e.,Since t h e temperature range o f t h e a v a i l a b l e data f o r plutonium n i t r a t es o l u t i o n s i s about 30 t o 130 C, t h e r e was a need t o c o r r e l a t e t h ep r o p e r t i e s o f t h e n i t r i c a c i d water system over a r e l a t i v e l y l a r g etemperature range.B.EXTENSION.OF HALA'S TREATMENT TO NONISOTHERMAL CONDITIONS.The approach described below was developed i n t h e c o n t e x t o f f i t t i n g-t h e v a p o r i z a t i o n e q u i l i b r i u m data f o r the%HN03 H20 system, usingt h e i n f o r m a t i o n a v a i l a b l e i n i t i a l l y t o t h e author (Hala's c o m p i l a t i o n 9and t h e t a b l e s i n - P e r r y ' s Chemical Engineering Handbook13 ).Since thena more complete s e t o f data has been c o l l e c t e d . 13-25' The l e a s t squares7
f i t s were performed usi ng the GNLS code26 and/or standard polynomi a1f i t r o u t i nes.The vapor pressures o f the pure components were taken t o be, f o r n i t r i c,acid,0log Pi 8.25225-(32)1918.3T,which was obtained by f i t t i n g the pure HN03 vapor pressure a J u e fso r the range 30 t o 100 C.i s poorer below 30 C.high).(Mean error i n P is 0.31 percent; however, the f i tA t 20 C , the predicted pressure i s about 7 percentAntoine's equation was used f o r water:which f i t s the water data w i t h a mean error of 0.1 percent.For each of the nineteen s e t s of data (Table 1) the log (Y;?/Y )calculated and f i t using Eq. (22) and the GNLS code.t o the 50 C data of Yakimov and Mishin.20TABLE 1.Figure 1 shows the f i tA t this point we f o u n d thatLiquid-vapor data used i n the correlations of the HN03Ref. no.Authors-H20 system.Data used23Wilson and Miles15, 20 C17Vandoni and Landy2020Yakimov and Mishin25, 35, 50 C21Boublik and Kuchinka50, 100, 200, 400, 760 Torr24Pot i e r450, 600, 760 Torr22Prosek740 Torr13Perry(Table 3-65)wasc60, 80, 100, 110 C.
1.2I1III01.a0.E0.E0.40.2P1hlo IF2 -0.2-0P)- 0.4-0.6- 0.8-1.0- 1.2- 1.4--01IIII0,FIG. 1log (yIk2/y3) vers,us n i t r i c a c i d mole f r a c t i o n (Ref. 20).9I
t h e data o f Wisonand M i l e s z 3 and P o t i e r Z 4 s c a t t e r e d e x c e s s i v e l y andd i d n o t show t h e same t r e n d s as t h e r e s t o f t h e data.We found t h a t i f t h e l o gf i t s was p l o t t e d versus(Y: /Y )-c a l c u l a t e d from t h e above i n d i v i d u a l1/T a t constant composition ( F i g . 2), t h e d a t a c o u l dbe approximated by a l i n e a r f i t , such t h a t a t c o n s t a n t compositionThe l a c k of f i t o f t h e d a t a of Wilson and M i l e s z 3 and P o t i e r P 4 waseven more pronounced i n t h i s c o r r e l a t i o n and these data were e l i m i n a t e dThe equi 1 ib r i um Val ues tabu1 a t e d infrom a1 1 subsequent mani pul a t ions.Perry13 f i t smoothly i n t o t h e data o f B o u b l i k and Kuchinka andof Prosek"and were used, p a r t i c u l a r l y t o p r o v i d e a d d i t i o n a l p o i n t sa t low a c i d c o n c e n t r a t i o n .[Eq.(34)]We a l s o found t h a t t h e values o f A andBgave a smooth curve when p l o t t e d versus c o n c e n t r a t i o n and t h egeneral shape o f t h e curves was such t h a t i t seemed reasonable t oexpress Eqs. (20) through (22) as a f u n c t i o n o f temperature i n t h e f o r m) (AoB6(Ao F ) 'I2) (B A1 X1 A2 X1(A1 ) X1B1 X1 B2 X;")/T(35)0B2 112 (A2 t-)Xl-(A2 T(36)(37)The data were then f i t t o o b t a i n t h e c o e f f i c i e n t s t o Eqs. (35) through (37).U n f o r t u n a t e l y , t h e f i t was n o t good, as can be seen i n Fig. 3, where t h e10
1C-1-20--4-5-6-7-82526FIG. 22728293031I/T x 104 for X, 0.2323334log (y1 2/y3)'versus l / T a t constant l i q u i d composition.-1135
I .log ( r-, * /calc )FIG. 3Comparison o f experimental 0.5 calculated log (yIk*/y3).12
2y3) i s plotted.calculated vs. experimental. value of log (yl -The cor-responding vapor compositions were also calculated and compared t o the,Figure 4 shows that most of the s c a t t e r takes place f o rexperimental ones.liquid mole fractions below 0.32.(2Since a major source of uncertainty i n the values of log yl /y3-) arisesfrom the errors i n measurement o f vapor composition, the formulationforY21 and y 3 was used t o yield an expression f o r the total pressure-from which a f i t of total pressure versus temperature and liquid composit i o n 2 8 could be obtained.The total pressure i s given bywhere the values of the a c t i v i t y coefficients can be obtained from Eqs.(36) and (37), and- x1xl - 1 . x1(39)- x,x11x3 -- 1 t o obtainThe best f i t parameters were as follows:A,-1.4295Bo 0.99860.9521B1 3.1429A2 -0.2422B2 0.9858A1 13
i.60Liquid nitric acid concentrationFIG. 4Cunparison o f calculated w i t h experimental vapor composition,log (u1 2/Y3)fit-14
A comparison o f t h e c a l c u l a t e d versus experimental pressure i s shown i nFig. 5 and t h e vapor compositions a r e compared.in F i g . 6; again, mosto f t h e s c a t t e r seems t o o r i g i n a t e w i t h l i q u i d compositions below about0.32 mole f r a c t i o n ., IC l e a r l y , t h e r e i s something wrong e i t h e r w i t h t h e d a t a o r w i t h t h ec o r r e l a t i o n techniques being used.However, s i n c e Hala and co-workershave been successful i n c o r r e l a t i n g t h e p r o p e r t i e s o f a number o f b i n a r yand multicomponents systems, and, as mentioned e a r l i e r , t h e problemso n l y a r i s e when c o r r e l a t i o n i s attempted o v e r a l a r g e temperature range,i t i s l i k e l y t h a t t h e problem o r i g i n a t e s elsewhere.C.CORRELATION OF RELATIVE VOLATILITIESSince t h e above approach d i d n o t y i e l d s a t i s f a c t o r y r e s u l t s and ourmain i n t e r e s t was t o be a b l e t o e x t r a p o l a t e t h e few a v a i l a b l e data onplutonium n i t r a t e s o l u t i o n s , t h e more e m p i r i c a l approach o f F u r t e r29-31was t r i e d .The f i r s t s t e p i n t h e process i s t o o b t a i n a c o n s i s t e n t s e to f r e l a t i v e v o l a t i l i t i e s f o r pure n i t r i c acid.The same s e t o fd a t a used above was manipulated t o o b t a i n t h e r e l a t i v e v o l a t i l i t i e sc o r r e l ations.The r e l a t i v e v o l a t i l i t y ,a,i s d e f i n e d byThere was reasonably good agreement i n t h e r e l a t i v e v o l a t i l i t i e s calcul a t e d from data from various i n v e s t i g a t o r s , provided t h e temperaturerange spanned was r e s t r i c t e d .The data were f i t u s i n g standard p o l y -nomial f i t r o u t i n e s , f o r c e d t o an assumed value o f a 0.001 a t X1 0:15
PressureFIG. 5Comparison of calculated and experimental pressures ( t o t a lDressure f i t ) .16
2500C.-0.-G 2000 Q)U8C-.-w0 .EC 1500Q)0C00x000-5.- 1000CBQs 500 - ' '00 "0.05t 0.10y-0.150.200.250.300.350.40 0.450.500.550.60Liquid nitric acid concentration, X,FIG. 6Comparison of c a l c u l a t e d versus experimental vapor compositions( t o t a l pressure f i t approach).17
B1X1 B2X 2 B 3 X3a B(43)0The r e s u l t s f o r data around 60 C are compared i n F i g . 7, and for dataaround 100 C i n Fig. 8.As was the case i n the a c t i v i t y coefficientcorrelations, there i s good f i t i f the temperature range of the d a t a i srestricted b u t excessive s c a t t e r when the temperature range i s extended, evenwhen an attempt i s made t o compensate for the effects of temperature by usinga (Ao A l t ) (Bo B1 X1 B2 X12 B3 XI)3(44 1The r a t i o of the experimental t o the calculated relative v o l a t i l i t yu s i n g Eq. (44) i s p l o t t e d versus l i q u i d composition i n F i g . 9.The d a t aused t o calculate F i g . 9 are given in’Table 2 and the coefficients f o rthe polynomial f i t equations i n Table 3.D.POSSIBLE REASONS FOR THE LACK OF F I TMost of the work described above was finished before a more thoroughl i t e r a t u r e search was completed t h a t adds not only add tional 1 i q u i dvapor equilibrium d a t a , b u t most importantly, i l l u s t r a l2sthe complexityof the HN03-HzO system.The calculations of a c t i v i t y coefficients using compositions derived fromEq. 5-16 assume that HN03 i s a strong (i.e.,completely dissociated)electrolyte and t h a t the only species present i n the liquid phase are H-, NO3 , andH20.In f a c t , these assumptions are not correct.HN03 i s only partially dissociated i n aqueous solutions and there are anumber of complexes i n the HN03-H2018system.
1.o0.80.200,0.10II0.20.3Mole fraction nitric acid in liquid, X,FIG. 7N i t r i c acid-water r e l a t i v e v o l a t i l i t y a t about 60 C.'1190.4
1.o0 - Reactor Handbook0.8U.-5 0.6- lu0 .-s%0.4alK0.20Mole fraction nitric acid in liquid, X,FIG. 8.Nitric acid relative v o l a t i l i t y a t about 100 C.20
I10-I1II021001V000OO80 000-I0.0500O0 00.1008080000- 007IIII0.150.200.250.300.35Mole fraction nitric acid in liquid, X,FIG. 9Ratio o f experimental t o calculated relative v o l a t i l i t i & over anextended temperature range.See Eq. ( 4 4 ) .- . .21
TABLE 2.Data used i n t h e c o r r e l a t i o n o f r e l a t i v e v o l a t i l i t y over an extendedtemperature range.Reference no.AuthorsData used--i20Yakimov and M i s h i n2122B o u b l i k and Kuchinka13Perry, Table 3-65TABLE 3.50 C50, 100, 200, 400, 760 t o r r740 t o r rProsek60, 80, 100, 110 CC o e f f i c i e n t s f o r t h e polynomial f i t s t o r e l a t i v e v o l a t i l i t y ,Eqs. (43) and (44).auTemperaturerange,Coefficient o 0.887290-11040- dbooka Range o f X1:0 X1 0.38.22determination,0.9970.996-0.998
The degree o f d i s s o c i a t i o n o f HN03, a , i s a f u n c t i o n o f c o n c e n t r a t i o nand temperature32,33HN03 H' NO3(45)and v a r i e s between 0.985a t 25 C f o r 1 molar a c i d (X1 0.0183)0.081 a t 70 C and 17.2 molar a c i d (XI 0.4625).t h e d i f f e r e n c e i n c o n c e n t r a t i o n o f NO3-andF i g u r e 10 i l l u s t r a t e st h a t o b t a i n s between t h eC i s t h e s t o i c h i o m e t r i c concentration,f u l l y and p a r t i a l l y i o n i z e d acid.and t h e c o n c e n t r a t i o n o f t h e i n d i v i d u a l species i s g i v e n byHN03C(1-a)H CaN03-CaThe second reason f o r t h e l a c k o f f i t i s t h e e x i s t e n c e o f HN03-H20complexes.The thermodynamic p r o p e r t i e s o f t h e s o l i d mono- and tri-hydrates have been measured34 and thermodynamic a n a l y s i s o f HN03-H20s o l u t i o n s data, 35-37 i n d i c a t e s t h a t t h e mono- and t r i h y d r a t especies a r e s t a b l e and should be considered i n t h e a n a l y s i s o f thermodynamic data f o r n i t r i c acid.The r e l a t i v e c o n c e n t r a t i o n s o f t h ev a r i o u s species changes as t h e t o t a l a c i d c o n c e n t r a t i o n i s increased(Fig. 11).From Fig. 11 i t can be seen t h a t t h e t r i h y d r a t e complex i s an importantspecies a t c o n c e n t r a t i o n s below 16M (about 0.4 mole f r a c t i o n ) , which i swhere most o f t h e s c a t t e r i n t h e c o r r e l a t i o n s occurs.It i s l i k e l y t h a tt h e t r i h y d r a t e complex decomposes i n t h e temperature range 60 t o 100 C andt h e thermodynamic a n a l y s i s should i n c l u d e it.23
Stoichiometric molarity of nitric acidFIG. 10M o l a r i t y o f n i t r a t e i o n versus s t o i c h i o m e t r i c c o n c e n t r a t i o n o fn i t r i c acid ( s o l i d l i n e s ) .The dashed p o r t i o n s o f these l i n e s show r e l a t i v evalues o f t h i s q u a n t i t y f o r concentrated s o l u t i ons.dissociation.OC represents completeFrom Ref. 33.,24
rMole rom Krawetz data20 -- 150 Calc. this work--SIT--0.10 -5-0MolarityFIG. 11acid.C(l- a) p l o t t e dagainst the stoichiometric m o l a r i t y o f n i t r i cFrom Ref. 2.25-
A f u l l thermodynamic a n a l y s i s and c o r r e l a t i o n o f a l l a v a i l a b l e data i s ,however, c o n s i d e r a b l y beyond t h e scope o f o u r program.111.ANALYSIS OF PLUTONIUM NITRATE SOLUTIONS LIQUID-VAPOR EQUILIBRIUM DATAThe range o f compositions o f plutonium n i t r a t e s o l u t i o n s o f i n t e r e s t i nt h e n u c l e a r f u e l c y c l e range from those a t t h e o u t l e t o f t h e 3B e x t r a c t i o ncolumns i n t h e Purex process (approx. 50 g/a o f Pu*) t o those a t t h e o u t l e t o ft h e Pu c o n c e n t r a t o r , which were t o be i n t h e range o f 250 t o 500 g/a.n i t r i c a c i d c o n t e n t ranges from about 0.5 t o 7 molar.The f r e eThe chemistry o f(IV) n i t r a t e complexes can be summarized as f o l l o w s , taken fromplutoniumC1 eve1 and38:N i t r a t e i o n s complex t e t r a v a l e n t p l u t o n i u m t o form a11i o n s from P u ( N O ) t o P u ( N O 2) .; i n concentrated HN03s o l u t i o n s , t h e l a t t e r i s t h e predominant complex.Studies o f t h e v a r i a t i o n o f t h e e x t i n c t i o n c o e f f i c i e n t o f Pu ( I V ) n i t r a t ei n v a r i o u s s o l v e n t s have l e d t o t h e c o n c l u s i o n t h a t Pu ( I V ) i s associatedw i t h an average o f 2.6 n i t r a t e i o n s i n aqueous . s o l u t i o n s c o n t a i n i n g 2 t o 4MThere i s c o n f l i c t i n g i n f o r m a t i o n about t h e range o f s t a b i l i t y o f t h enitrate. Pu (NO3I3complex, b u t i t i s l i k e l y t o be t h e dominant species i n t h erange o f 1.5 t o 4.0M f r e e HN03.Pu (NO3I4 i s s t a b l e i n t h e r e g i o n 3.82- f o r concentrat o 5.6 M, Pu (N0315- from 5.6 t o 7.1 M and Pu (NO3I6t i o n s g r e a t e r t h a n 7.1M.The abundance o f t h e h e x a n i t r a t o complex i s giveni n Table 4. *Nomi nal compositions, A1 1 i e d General Nucl ear Services (AGNS) reprocessingp l ant.26
TABLE 4:Abundance o f Pu(,IV) h e x a n i t r a t o complex i n HN03 s o l u t i o n s . 38"03,Abundance o f Pu ( NO3)M546107298509751091119562:%13100V a p o r i z a t i o n e q u i l i b r i u m data obtained a t t h e t i m e t h e Purex processwas being designed a r e summarized i n t h e Reactor Handbook, Vol.11"andt h e Purex Technical Manual 39; more r e c e n t l y , Swanson12 performed a numbero f measurements on concentrated plutonium s o l u t i o n s .Swanson's data weremade a v a i l a b l e t o us by A l l i e d General Nuclear Services, o f Barnwell, S.C.--The i n f o r m a t i o n i n t h e Reactor Handbook and t h e Purex Technical Manual wasi n t h e form o f smooth graphs, and even t h e source d o c u m e n t d i d n o tc o n t a i n t h e raw experimental data.I t was assumed t h a t a l l t h e above datawas obtained a t - - o r near t o - - t h e nqrmal b o i l i n g p o i n t o f t h e s o l u t i o n s a t760 t o r r .The i n f o r m a t i o n i n t h e v a r i o u s f i g u r e s , such as Figs. 12 and 13was d i g i t i z e d and manipulated u s i n g a 9830 Hewlett-Packard computer, thus i tmay appear as many i n d i v i d u a l "data" p o i n t s i n some o f t h e computer p l o t s o fpolynomial l e a s t squares f i t s .The s i z e o f t h e o r i g i n a l Fig. 13 i n t h eReactor Handbook i s o n l y 2-1/2 inches square, t h u s appreciable r e a d i n g e r r o r sc o u l d o b t a i n d u r i n g t h e d i g i t i z i n g process, p a r t i c u l a r l y a t low plutoniumconcentrations.27
900I1I1I10 Swanson'sdata points0125 C8000120 c700Boiling point 150 C600\CI)C'0'sE 500c,-ca0C125 C112c 0111 c oidist iIIa tion Iinesupward indicatescomposition changebatch evaporation.I00E.3 400-C0Y514Hydrogen ion concentration, moles/lFIG. 12IB o i l i n g p o i n t s and r e g i o n o f polymer formation f o r plutonium-HN0 3s o l u t i ons (Ref. 42).28
1615-14-13-12-11-Pu 200 g/1pu 300 9119--8--7--"8 10-(IIru. IURIE*(II.-0L.Ez6--5--4---012345687-9101112Nitric acid - vapor phase - MFIG. 13E q u i l i b r i u m diagram29(Ref. 39).13141516
The l a c k o f good a c t i v i t y c o e f f i c i e n t s f o r n i t r i c a c i d and t h e complexchemistry of plutonium s o l u t i o n s prevented a thorough a n a l y s i s o f t h e data,i n p a r t i c u l a r , t h e data on b o i l i n g p o i n t versus l i q u i d composition of'Pugh 40and Swanson"were n o t analyzed; t h e a n a l y s i s was c o n f i n e d t o t h e a v a i l a b l el i q u i d - v a p o r e q u i l i b r i u m data.Hal a e t a1A., Eqs.The data were examined u s i n
P UCID- 18148 VAPOR-LIQUID EQUILIBRIA FOR NITRIC ACID-WATER AND PLUTONIUM NITRATE-NITRIC ACID-WATER SOLUTIONS A. MAIMONI Januarv 1980 This work was supported by the United States Nuclear Regulatory Commission under a Memorandum of Understanding with the United States Department of Energy.
Nitric Oxide Precursors The first recognized nitric oxide precursor was the amino acid arginine, which is converted to NO by a family of enzymes called Nitric Oxide Synthases (NOSs) NitroFx and NitroXtreme represent a second generation of Nitric Oxide precursors.
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Liquid Vapor Liquid Vapor Liquid Evap. Vapor Liquid Vapor Temp. 2 8F lbf/in. v f v g u f u g h f h fg h g s f s g 8 F 32 0.0886 0.01602 3305 2.01 1021.2 2.01 1075.4 1075.4 2.00003 2.1870 3 2 35 0.0999 0.01602 2948 2.99 1022.2 3.00 1073.7 1076.7 0.00607 2.1764 35 40 0.1217 0.01602 2445 8.02 1023.9 8.02 1070.9 1078.9 0.01617 2.1592 40 .
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LÄS NOGGRANT FÖLJANDE VILLKOR FÖR APPLE DEVELOPER PROGRAM LICENCE . Apple Developer Program License Agreement Syfte Du vill använda Apple-mjukvara (enligt definitionen nedan) för att utveckla en eller flera Applikationer (enligt definitionen nedan) för Apple-märkta produkter. . Applikationer som utvecklas för iOS-produkter, Apple .
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