HOME
..
..
*
3
HELP
ST
O A K RIDGE N A T I O N A L LABORATORY
L
b
.
operated b y
U N I O N CARBIDE CORPORATION
f o r the
U.S. ATOMIC ENERGY COMMISSION
ORNL- TM- 3144
COPY NO.
DATE
-
-
cs
September 30,
FLUORINE PRODUCTION AND RECOMBINATION I N
FR
' OmN MSR SALTS AFTER REACTOR OPERATION
P.- N.- Haubenreich
ABSTRACT
Exposure of c a p s u l e s of MSR f u e l s a l t s i n t h e MTR between 1961
and 1964 showed t h a t when t h e s a l t was c h i l l e d below about 80°c, F2
w a s produced by r a d i o l y s i s a t a r a t e of 0.02 molecules/100 ev. Other
experiments confirmed t h e r a d i o l y s i s of f r o z e n s a l t and provided d a t a
on t h e e f f e c t of temperature on recombination, The d a t a on y i e l d and
recombination have r e c e n t l y been reviewed and used i n answering quest i o n s involved i n s t o r i n g and d i s p o s i n g of i r r a d i a t e d s a l t from t h e MSRE
and f u t u r e m o l t e n - s a l t r e a c t o r s . The energy source i n t h e MSRE s a l t i s
low enough t h a t no f l u o r i n e e v o l u t i o n i s expected f o r over a y e a r after
h e a t i n g t o induce recombination. Salt from a high-power MSR can be
s t o r e d i n b a r e cans w i t h no f l u o r i n e e v o l u t i o n i f t h e surroundings a r e
k e p t a t a b o u t 200°F.
Keywords: m o l t e n - s a l t r e a c t o r s , f l u o r i n e , f u s e d salts, r a d i o l y s i s ,
s t o r a g e , waste d i s p o s a l , af t e r h e a t , a n a l y s i s , experiment, h e a t t r a n s f e r ,
MSRE, primary salt, r e a c t i o n rates, recombination.
C'
L
b
~
, ;**
NOTICE This document contains information of a preliminary nature
and was prepared primarily for internal use a i the O a k Ridge National
Laboratory. It is subject to revision or correction and therefore does
not represent a final report.
1970
,--
.
-
.
--
- LEGAL NOTICE
‘ e
~
T h i s report was prepared as an account of Government sponsored work.
Neither the United States,
nor the Commission, nor ony person acting on behalf of the Commission:
A.
Makes any warranty or representation, expressed or implied, w i t h respect t o the occuracy,
completeness, or usefulness of the information contained i n t h i s report, or that the use of
any
information,
apparatus,
method,
or process disclosed
i n t h i s report may not infringe
privately owned rights; or
6. Assumes any l i a b i l i t i e s with respect to the use of, or for damages resulting from the use of
any information, apparatus, method, or process disclosed in t h i s report.
As used i n the above, “person
acting on behalf of the
Commission”
includes ony employee or
contractor of the Commission, or employee of such controctor, t o the extent that such employee
or contractor of the Commission.
or employee
of
such contractor
prepares,
disseminates,
or
provides access to, any information pursuant t o h i s employment or contract w i t h the Commission,
or h i s employment w i t h such contractor.
-7
iii
CONTENTS
ABSTRACT
...........................
RESULTS OF THE 6oCo EXPERIMENT . . . . . . . . . . . . . . . . . .
D e s c r i p t i o n of the Experiment .
.
.
.
INTRODUCTION
,
*
..........................
e
Analysis.
e
E
i
3
2
2
. . . . . . . . . . . . . . . . . . . 15
. . . . . . . . . . . . . . . . . . . . . 15
RESULTS OF OTHER EXPERIMENTS
I n - P i l e Experiments
X-Ray I r r a d i a t i o n s
F a s t - E l e c t r o n Bombardment
Discussion
. . . . . . . . . . . . . . . . . . . . . . 18
. . . . . . . . . . . . . . . . . . 18
. . . . . . . . . . . . . . . . . . . . . . . . . . 18
STORAGE AND DISPOSAL OF MSRE SALT . . . . . . . . . . . . . . . . . 19
EnergySources . . . . . . . . . . . . . . . . . . . . . . . .
20
Temperature f o r I n t e r n a l Recombination . . . . . . . . . . . . 20
I n d u c t i o n P e r i o d and F l u o r i n e Release
. . , , . , 23
Discussion
. . . . . . . . . . . . . . . . . . . . . . . . . 24
e
e
a
..,
. 25
. . . . . . . . . . . . . . . . . . . . . . . . 25
. . . . . . ., . . . .. . .. . . 25
31
. . . . . . . . . . . 32
DEALING W I T H SALT FROM LARGE MOLTEN-SALT REACTORS
Energy Source
Heat T r a n s f e r and Temperatures
. ,
F l u o r i n e Y i e l d and I n d u c t i o n P e r i o d
Temperature for Zero Release of F l u o r i n e
Discussion.
.)
REFERENCES
I
a
.........................
32
............................
34
LEGAL NOTICE
This report was prepared as an account of work
sponsored by the United States Government. Neither
the United States nor the United States Atomic Energy
Commission, nor any of their employees, nor any of
their contractors, subcontractors, or their employees,
makes any warranty, express or implied, or assumes any
legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus,
product or process disclosed, or represents that its use
would not infringe privately owned rights.
c
W
e
INTRODUCTION
The phenomenon w i t h which t h i s r e p o r t i s concerned, t h a t i s , t h e
e v o l u t i o n of f l u o r i n e g a s from f r o z e n f l u o r i d e s a l t s s u b j e c t e d t o radia t i o n from i n c l u d e d f i s s i o n p r o d u c t s , was f i r s t observed i n 1962 i n caps u l e s t h a t had been exposed i n t h e MTR.l
Some c a p s u l e s (Expt. 47-4)
when opened s e v e r a l weeks a f t e r withdrawal from t h e r e a c t o r were found t o
have f l u o r i n e p r e s s u r e s as h i g h as 50 atmospheres.
It was e v i d e n t , b o t h
from t h e l a c k of metal c o r r o s i o n and from s t r e n g t h c o n s i d e r a t i o n s , t h a t
t h i s much F2 could n o t have been p r e s e n t while t h e c a p s u l e s were a t h i g h
temperature i n t h e r e a c t o r .
The n e x t experiment i n c l u d e d c a p s u l e s w i t h
p r o v i s i o n s f o r g a s sampling and p r e s s u r e measurement.
These proved t h a t
Fz was evolved o n l y when t h e s a l t was c h i l l e d well below t h e f r e e z i n g
point.
Monitoring of t h e s e c a p s u l e s a f t e r removal from t h e r e a c t o r showed
t h a t a t room temperature t h e rate of f l u o r i n e r e l e a s e was p r o p o r t i o n a l t o
t h e f i s s i o n p r o d u c t decay energy.
A t s l i g h t l y h i g h e r temperatures, t h e
F2 a p p a r e n t l y recombined w i t h t h e s a l t .
Meanwhile s e v e r a l experiments
had been done i n which f r o z e n f l u o r i d e s were s u b j e c t e d t o v a r i o u s k i n d s
of r a d i a t i o n from e x t e r n a l sources
.’,
These experiments produced f l u o r i n e
w i t h y i e l d s comparable t o those i n f e r r e d from t h e i n - p i l e c a p s u l e s .
In
one experiment, w i t h a 6oCo gamma-ray source, t h e e f f e c t of temperature
on f l u o r i n e e v o l u t i o n and recombination was e x p l o r e d d u r i n g more t h a n
7000 hours of o p e r a t i o n .
One conclusion from the experiments was t h a t f l u o r i n e e v o l u t i o n from
f r o z e n s a l t would pose no t h r e a t t o t h e o p e r a t i o n of t h e MSRE.
t i o n s were raised, however, when i n December
New ques-
1969 t h e r e a c t o r was s h u t
down and, f o r the f i r s t time a t t h e MSRE, t a n k s of f u e l s a l t were allowed
t o freeze.
During t h e i n t e r i m between t h e end of n u c l e a r o p e r a t i o n and
t h e p o s t - o p e r a t i o n examinations (scheduled f o r t h e f a l l of 1970) i t was
a simple matter t o keep t h e f r o z e n s a l t warm enough (>2OO0C) t o p o s i t i v e l y
p r e c l u d e any f l u o r i n e e v o l u t i o n .
During t h e n e x t phase (Phase 111) b e f o r e
t h e u l t i m a t e d i s p o s a l of t h e f i s s i l e and r a d i o a c t i v e materials, it would
be convenient t o t u r n o f f t h e heaters and l e t the s a l t s c o o l t o n e a r amb i e n t temperature.
I n a n t i c i p a t i o n of t h i s phase, then, t h e data on
f l u o r i n e e v o l u t i o n and recombination were reexamined.
2
RESULTS OF THE 6oC0 EXPERlMENT
O f t h e v a r i o u s experiments, t h e one t h a t c o n t a i n s t h e most informa-
t i o n on temperature e f f e c t s , which a r e of paramount importance i n t h e cons i d e r a t i o n f o r t h e shutdown MSRE, i s t h e 6oCo experiment.
D e s c r i p t i o n of t h e Experiment2
The equipment f o r t h i s experiment c o n s i s t e d of a 25-cm3 Hastelloy-N
a u t o c l a v e with p r o v i s i o n s f o r temperature c o n t r o l and measurement and w i t h
two 1/8-in.
n i c k e l t u b e s f o r g a s sampling and p r e s s u r e measurement.
Y
Powdered s a l t (35 g) of a composition
s i m i l a r t o t h a t proposed f o r t h e
MSRF: f u e l was melted i n t h e a u t o c l a v e , an a r r a y of 24 small g r a p h i t e
s p h e r e s was i n s e r t e d and t h e s a l t was allowed t o f r e e z e b e f o r e t h e a u t o c l a v e was s e a l e d .
All i n t e r i o r s u r f a c e s of t h e equipment were p r e f l u o r i -
n a t e d b e f o r e t h e s a l t was added.
The assembly was p l a c e d i n a 6oCo i r r a d i a t i o n f a c i l i t y and l e f t t h e r e
f o r 7391 hours between February and December, 1963.
During t h i s time t h e
temperature was h e l d a t v a r i o u s l e v e l s between 38°C and 150°C, t h r e e
Sam-
p l e s of g a s were taken, t h e source was removed twice t o i n t e r r u p t t h e
gamxa-ray i r r a d i a t i o n , and t h e p r e s s u r e was observed c o n t i n u o u s l y .
With
t h e source i n p l a c e , t h e energy a k s o r p t i o n r a t e was 0.45 x lo2’ ev/hr-g
The temperature of t h e s a l t and t h e t o t a l g a s p r e s s u r e e v e r t h e
salt.
s a l t d u r i n g t h e experiment a r e
heliun: a t
S ~ G ~i nR
F i g . 1. An atmosphere of pure
16 t o 18 p s i a was e s t a b l i s h e d over t h e s a l t i n i t i a l l y and a f t e r
each sample.
Analysis of t h e eamples showed t h a t t h e p r e s s u r e changes
were due t o changes i n t h e amount of f l u o r i n e i n t h e gas phase.
Analysis
The o r i g i n a l analysis.‘ of the experiment produced t h e f o l l c w f n g ccnciusions.
It was e v i d e r t t h a t p r a c t i c a l l y pure F2 gas w a s prcduced by t h e
gamma i r r a d i a t i o n of s o l i d MSRE s a l t i n the presence of g r a p h i t e .
ic
LiF-BeF2-ZrF4-ThF4-LT4
(69.0
-
23.0 - 5.2 - 1.7
-
21t h e
l.1 mole $,).
3
F i g . 1. P r e s s u r e and Temperature vs Time i n a F l u o r i d e S a l t Autoclave
Under Gamma I r r a d i a t i o n
4
absence of r a d i a t i o n o r a t e l e v a t e d temperatures i n t h e presence of r a d i a t i o n t h e g a s d i s a p p e a r e d a t a measurable r a t e , presumably recombining
with the salt.
Other p o i n t s were t h a t f o l l o w i n g complete recombination,
F2 d i d n o t reappear i n t h e gas phase u n t i l a f t e r an " i n d u c t i o n p e r i o d , "
t h a t temperature s t r o n g l y a f f e c t e d t h e recombination r a t e , and t h a t F2
p r e s s u r e had l i t t l e if any e f f e c t on t h e r e l e a s e r a t e o r recombination.
The remainder of t h i s s e c t i o n w i l l propose a simple model f o r t h e
mechanisms involved and e x t r a c t from t h e 6oCo experiment some numbers
t h a t w i l l be u s e f u l i n c a l c u l a t i o n s f o r t h e MSRF and MSBR f u e l .
Hypotheses
L e t u s adopt t h e f o l l o w i n g hypotheses as a basis f o r r e d u c i n g t h e
6oCo d a t a t o some q u a n t i t i e s t h a t can be a p p l i e d t o o t h e r s i t u a t i o n s .
1. F l u o r i n e molecules (F2) were produced i n t h e f r o z e n s a l t a t a
* The pror a t e p r o p o r t i o n a l t o t h e a b s o r p t i o n of energy from gamma r a y s .
p o r t i o n a l i t y f a c t o r , G, was independent of temperature.
2.
F l u o r i n e was evolved i n t o t h e g a s phase o n l y a f t e r t h e average
c o n c e n t r a t i o n i n t h e s a l t reached some l i m i t i n g v a l u e .
3.
F l u o r i n e recombined w i t h t h e s a l t a t a r a t e p r o p o r t i o n a l t o t h e
c o n c e n t r a t i o n of r a d i o l y t i c f l u o r i n e w i t h i n t h e s a l t .
3cx
The p r o p o r t i o n -
a l i t y f a c t o r was a f u n c t i o n o n l y of temperature.
Represent t h e s e hypotheses by
P
=
GE/~OO
K
=
k(T)C
R
=
P
- KR
=
P - k(T)cR
*I n
a c t u a l i t y , r a d i o l y t i c f l u o r i n e probably e x i s t s w i t h i n t h e s a l t
l a t t i c e as s i n g l e atoms, which form F2 molecules o n l y a f t e r t h e y have m i g r a t e d t o a s u r f a c e . The f o l l o w i n g d e s c r i p t i o n i s s i m p l i f i e d ( w i t h o u t
a f f e c t i n g the r e s u l t s ) by t r e a t i n g t h e f l u o r i n e w i t h i n t h e s a l t as an
e q u i v a l e n t number of F2 molecules.
**O r
t h e c o n c e n t r a t i o n r a i s e d t o some power n : t h e r e i s no way t c
t e l l from t h i s experiment t h e v a l u e c f n, b u t i t makes no d i f f e r e n c e i n
the a p p l i c a t i o n s we p l a n t o make.
5
where
c =
average c o n c e n t r a t i o n of
F2 i n s a l t , molecules/g
E = r a t e of energy a b s o r p t i o n i n s a l t , e v / h r
G
-
g
y i e l d , molecules/100 e v
=
K = r a t e of recombination of F2 w i t h s a l t , m o l e c u l e s / h r
k
=
recombination f a c t o r , h r -
P
=
rate of p r o d u c t i o n of F2 i n salt, m o l e c u l e s / h r
R
= r a t e of r e l e a s e of F2 from s a l t , molecules/hr - g
= temperature of s a l t , OK
T
Sub R
=
-
-
g
g
v a l u e s while r e l e a s e i s o c c u r r i n g .
I n t e r p r e t a t i o n of t h e Data
L e t us f i r s t d e r i v e v a l u e s f o r K d u r i n g t h e i n t e r v a l s when t h e source
was o u t (making E and P z e r o ) .
During t h e s e i n t e r v a l s t h e r e l e a s e r a t e
was n e g a t i v e and e q u a l t o t h e r a t e of recombination i n t h e s a l t .
The r e l e a s e r a t e can be computed from t h e r a t e of p r e s s u r e change.
Savage, Compere, and Baker2 g i v e t h e formula
G
=
0.0073 &
At
when
E
where t h e u n i t s a r e :
psi/lOOO h r .
=
0.45
X
lo2'
G, molecules F2/100 ev; E, Ev/hr-g;
and &/At,
From t h i s information, t h e r e l e a s e r a t e i n molecules
F2/hr-g i s given by
R = - GE
-
100
- 0.0073
2x
0 * 4 5 'OZo
100
=
0.328 x 1016 &
at
Table 1 g i v e s t h e observed r a t e of p r e s s u r e change and t h e computed
v a l u e of R d u r i n g i n t e r v a l s w i t h t h e source o u t .
(These times and p r e s -
s u r e s were taken from t h e o r i g i n a l d a t a s h e e t s 4 and t h e i n t e r v a l s were
6
Table 1
F l u o r i n e ConsumDtion w i t h t h e Source Removed
Interval (hr)
From
To
'At
Temp.
("C)
5542.5 559.0
47.5
110
20.21
5593.0
5637.0
7075.5
7221.8
7293.0
25.5
150
110
110
20.99
19.79
21.04
130
21.05
150
20.89
5618.5
5708.7
71.7
7221.0 145.5
7291.5 69.7
7381.1 88.1
20.14
20.43
19.58
20.78
20.63
19.02
-
si
Pressure (psi)
Start
End
Ap
(lOE0 h r
-0.07
-0.56
- 1.47
-0.21
-
10-I6R
(mol;;u;s
-22.0
2.93
- 1.79
- 6.03
-0.26
-0.42
-1.87
-21.2
)
0.48
7.22
0.96
0.59
1.98
6.95
chosen t o e l i m i n a t e t r a n s i e n t p e r i o d s a s s o c i a t e d w i t h changing temperatures.)
Since a f u n c t i o n a l r e l a t i o n s h i p of k and T of t h e form
k
=
a e
-b/T
1/T.
i s a good p o s s i b i l i t y , l e t u s t r y a p l o t of I n R
( I n attempting
such a r e p r e s e n t a t i o n , one i m p l i e s t h a t K, which i s t h e p r o d u c t of k and
CR, i s a f u n c t i o n of temperature having t h e above form.
v e n i e n t approximation, as w i l l be seen l a t e r . )
T h i s i s a con-
Figure 2 shows t h a t indeed
data do seem t o show t h e a n t i c i p a t e d dependence on temperature.
The l i n e
i n t h e f i g u r e was f i t t e d t o t h e data, t a k i n g i n t o a c c o u n t t h a t some p o i n t s
a r e more r e l i a b l e because t h e y were measured over g r e a t e r i n t e r v a l s .
e q u a t i o n of t h e l i n e i s
K
=
6.65 x
e
-9710/T molecules
hr- g
The
'7
OWL-DWG.
(x
TI MPL K A I W L .
Idb)
( O c }
2.5
2.4
T
70-12905
2.6
(OK-')
Fig, 2. Fluorine Consumption i n Autoclave kh- 3ecorfcication w i t h
S i n u l a t e d MSF23 Fuel Salt
a
L e t u s t u r n now t o t h e observed r a t e s of p r e s s u r e change while t h e
s a l t w a s being i r r a d i a t e d .
During t h r e e i n t e r v a l s t h e release r a t e was
z e r o because t h e c o n c e n t r a t i o n of F2 i n t h e s a l t was below t h e t h r e s h o l d ,
Co.
The f i r s t was t h e i n i t i a l i n t e r v a l a t ambient temperature ( a b o u t
50°c),
when t h e s a l t was i r r a d i a t e d f o r more t h a n 600 h r b e f o r e any p r e s s u r e i n c r e a s e occurred.
a f t e r Sample 3.
discussed l a t e r . )
Sample 3.
Another was t h e i n t e r v a l of similar l e n g t h a t 110°C
(The s i g n i f i c a n c e of such " i n d u c t i o n periods'' w i l l be
The o t h e r i n t e r v a l was t h e 1.50 h r a t 150°C j u s t b e f o r e
The p r e s s u r e had decreased r a p i d l y j u s t b e f o r e t h i s u n t i l a l l
t h e F2 was o u t of t h e g a s ( v e r i f i e d by Sample 3), i n d i c a t i n g t h a t recombin a t i o n was exceeding p r o d u c t i o n .
Thus, a f t e r t h e p r e s s u r e became c o n s t a n t
t h e F2 c o n c e n t r a t i o n i n t h e s a l t presumably continued t o d e c r e a s e .
The r a t e s of p r e s s u r e change d u r i n g a l l t h e i n t e r v a l s when t h e source
was i n and t h e r e was s i g n i f i c a n t F2 p r e s s u r e i n t h e g a s a r e l i s t e d i n
Table 2 and i n F i g . 3 t h e y a r e p l o t t e d a g a i n s t temperature.
These p r e s s u r e
changes a r e , of course, p r o p o r t i o n a l t o t h e d i f f e r e n c e between p r o d u c t i o n
and recombination, and t h e e f f e c t of i n c r e a s i n g recombination r a t e a t
h i g h e r temperatures c a u s e s t h e p r e s s u r e change t o be n e g a t i v e even though
f l u o r i n e i s s t i l l b e i n g produced i n t h e s a l t .
The p r o d u c t i o n r a t e can
be computed by adding t h e recombination r a t e c a l c u l a t e d from Fig. 2 t o
t h e rate of F2 r e l e a s e i n d i c a t e d by t h e observed p r e s s u r e change.
(In
doing t h i s we must assume t h a t t h e recombination rate d u r i n g a n i n t e r v a l
of p r e s s u r e i n c r e a s e was t h e same as d u r i n g an i n t e r v a l of p r e s s u r e dec r e a s e w i t h t h e source o u t a t t h e same temperature, which i s t o s a y t h a t
CR i s a b o u t t h e same when t h e r e was an outward flow of f l u o r i n e from t h e
s a l t as when t h e r e was an inward flow.)
Figure
4 shows
t h e r e s u l t s of
t h i s computation.
Some of t h e d i f f e r e n c e s between t h e p o i n t s i n F i g .
4 are
no doubt
due t o e r r o r i n h e r e n t i n t h e measurements, b u t t h e r e i s a l s o a s u g g e s t i o n
of some remaining temperature e f f e c t .
One s u s p e c t s t h e e f f e c t s of l i m i t e d
d i f f u s i o n r a t e s i n t h e s a l t and v a r i a t i o n of t h e same w i t h temperature,
b u t no firm conclusion i s j u s t i f i e d .
The band from 3 t o 8 psi/lOOO h r ,
which i n c l u d e s most of t h e p o i n t s , corresponds t o v a l u e s of G from 0.02
t o 0.06 molecules/100 ev, based on t h e energy a b s o r p t i o n r a t e of
W
9
Table 2
F l u o r i n e E v o l u t i o n from Salt Exposed t o 6oCo Source
I n t e r v a l (hr)
From
To
At
'
764
1008
1364
1774
1893
2713
2948
3217
3404
3741.
4033
4156
5084
5301.
5878
6217
6387
6603
6740
884
1343
1724
1871
2182
2852
3190
3357
3619
4029
4156
4268
5301
5541.
6142
6380
6596
6645
6979
Temp
(OC)
110
17.00
17.28
1-8.35
22.36
16.38
16.78
18.28
20.94
22.78
16.67
21.44
18.06
18.14
1-907
19.94
110
21.20
1.30
22.75
1.50
23.16
21.74
331
360
97
289
139
242
140
65
58
38
66
67
61
85
95
215
110
288
110
123
112
1.50
120
217
240
264
163
209
42
239
Pressure (psi)
Start
End
AP
150
110
110
130
17.28
18.74
20.44
22 97
17.40
17.28
20.14
22.09
23.78
19.08
18.06
16.09
19 07
20.28
20.84
22.18
22.74
22.44
21.39
.28
1.46
2.09
0.61
1.02
0.50
1.86
1.15
1.00
2.41
-3.38
-1.97
0.93
1.21
0.90
0.9
-0.01
-0.72
-0.35
AP/At
( 100; si
hr)
2.23
4.41
5.81
6.29
3.53
3.60
7.69
8.21
4.65
8.37
-27.5
-17.5
4.29
5 .Ob
3.41
6.01
-
0.05
-17.1
- 1.46
ORNL DUG. 70-12906
Fig.
W
11
Fig.
Y
4.
R a t e s of P r e s s u r e I n c r e a s e i n Salt Exposed to 6oCo Source That
Would Have R e s u l t e d i f There had been no Recombination
12
0.45 x lo2'
W
ev/hr-g.
If w e exclude t h e 1 5 0 ° C p o i n t s , which a r e v e r y
s e n s i t i v e t o temperature r e p r o d u c i b i l i t y ,
Fig.
4 corresponds
t h e average of t h e d a t a i n
t o G = 0.045 rnolecules/100 ev.
Now l e t us t u r n a g a i n t o "induction p e r i o d s . "
We would l i k e t o be
a b l e t o p r e d i c t f o r v a r i o u s k i n d s of s a l t under v a r i o u s c o n d i t i o n s how
much energy can be absorbed b e f o r e f l u o r i n e e v o l u t i o n b e g i n s .
This i s
n o t a c o n s t a n t , t h e most obvious v a r i a b l e s a f f e c t i n g it b e i n g temperature
and t h e r a t e of energy a b s o r p t i o n .
If t h e temperature were h i g h enough
o r E low enough, recombination would m a i n t a i n an F2 c o n c e n t r a t i o n i n t h e
s a l t below t h a t a t which any s i g n i f i c a n t F2 i s r e l e a s e d i n t o t h e g a s .
A t t h e o t h e r extreme, a t temperatures so low t h a t recombination i s negligible,
t h e p r o d u c t i o n would go i n t o r a i s i n g t h e c o n c e n t r a t i o n .
At
some i n t e r m e d i a t e temperature, C would i n c r e a s e more slowly because of
p a r t i a l recombination, b u t t h e l i m i t i n g c o n c e n t r a t i o n , CR, could conc e i v a b l y be lower so t h e i n d u c t i o n t i m e would n o t n e c e s s a r i l y be l o n g e r
t h a n a t low temperature.
I n t h e 6oCo experiments w e observed two i n -
d u c t i o n p e r i o d s , one a t 50°C where recombination was p r a c t i c a l l y n e g l i g i b l e
and t h e o t h e r a t 110°C where t h e recombination r a t e d u r i n g t h e i n d u c t i o n
p e r i o d p r o b a b l y ranged up t o roughly h a l f t h e p r o d u c t i o n r a t e ( s e e F i g . 3 ) .
Examination of t h e d e t a i l e d p l o t of t h e e x p e r i m e n t a l d a t a 4 shows t h a t t h e
50°C i n d u c t i o n p e r i o d was c l o s e t o TOO hours (3.1 x
110°C p e r i o d was a b o u t 630 hours (2.8 x
ev/g).
ev/g) and t h e
The F2 c o n c e n t r a t i o n
i n t h e s a l t a t t h e s t a r t of t h e l a t t e r p e r i o d was n o t q u i t e z e r o b u t was
p r o b a b l y p r a c t i c a l l y so.
Thus t h e f a c t t h a t , d e s p i t e g r e a t e r recombi-
n a t i o n , t h e i n d u c t i o n p e r i o d a t 110°C was a b o u t t h e same as a t 50°C i n d i c a t e s t h a t CR was indeed s u b s t a n t i a l l y lower a t t h e h i g h e r temperature.
F u r t h e r s u p p o r t f o r a lower CR a t h i g h e r temperature are t h e p r e s s u r e
t r a n s i e n t s accompanying some of t h e s t e p s i n temperature, which seemed t o
i n d i c a t e r a p i d r e l e a s e of f l u o r i n e when t h e temperature was r a i s e d .
From t h e foregoing, it i s a p p a r e n t t h a t t h e r e i s indeed a dependence
of CR w i t h temperature t h a t i s i n c l u d e d i n t h e e x p o n e n t i a l approximation
f o r kCR
T t h a t we d e r i v e d .
The probable d i f f e r e n c e i n t h e form of t h e
temperature dependence of k and of CR should n o t a f f e c t t h e f i t of t h e
e m p i r i c a l r e l a t i o n t o o much, however, because CR p r o b a b l y v a r i e s by a
v
f a c t o r of s e v e r a l while k i s v a r y i n g by a couple of decades.
It i s n o t
e s s e n t i a l t h a t we s e p a r a t e t h e r e l a t i o n s f o r k and CR; i n most a p p l i c a t i o n s what w e want t o know i s whether or n o t the temperature i s h i g h
enough so t h a t t h e r e w i l l b e no f l u o r i n e r e l e a s e ( t h a t t h e p r o d u c t kCR
i s l e s s than P ) .
Although t h e p o i n t h a s no s i g n i f i c a n c e f o r f u t u r e a p p l i c a t i o n s where
no f l u o r i n e p r e s s u r e i s allowed t o develop, it may be noted t h a t t h e d a t a
of t h e 6oCo experiment do n o t i n d i c a t e any c l e a r dependence of recombin a t i o n r a t e on f l u o r i n e p r e s s u r e i n t h e g a s .
Summary
Y i e l d ( p r o d u c t i o n i n t h e s a l t ) i n t h e s i m u l a t e d MSRE f u e l s a l t was
0.045 t 0.02 molecules F2/100 ev, w i t h l i t t l e or no dependence on t e m perature.
I n s a l t i n i t i a l l y f r e e of F2, a c o n s i d e r a b l e amount of energy
was absorbed b e f o r e any f l u o r i n e appeared i n t h e g a s o v e r t h e s a l t :
i n d u c t i o n p e r i o d s of 3.1 x loz2 and 2.8 x
5 5 ° C and 110°C r e s p e c t i v e l y .
ev/g were observed a t
R a t e s of recombination i n " s a t u r a t e d s a l t "
(when t h e r e was f l u o r i n e i n t h e g a s ) depended s t r o n g l y on temperature;
p r a c t i c a l l y n o t a t a l l on f l u o r i n e o v e r p r e s s u r e .
K
=
kCR
=
6.65 x
e
-
An e m p i r i c a l r e l a t i o n
molecules
hr-g
F2
f i t t h e d a t a w i t h i n 5 50%.
I n a p p l y i n g t h e s e r e s u l t s t o o t h e r s i t u a t i o n s , d i f f e r e n t u n i t s may
be convenient.
I n p a r t i c u l a r , t h e i n d u c t i o n p e r i o d and recombination
r a t e s should p r o b a b l y be r e l a t e d t o moles of s a l t r a t h e r t h a n weight of
salt.
Table 3 e x p r e s s e s t h e 6oCo experiment r e s u l t s i n v a r i o u s u n i t s .
14
Table 3
R e s u l t s of 6oCo I r r a d i a t i o n of Simulated MSRE Fuela
molecules F2
100 e v
Yield
0.045
Induction
Period
ev
3 . 0 ~ 1 0g ~ ~
Recombination
Coefficient
6.65~10~~h r - g
or
0.38
or
1.3
molecules F2
a
Composition:
STP)F,
watt - h r
CC(
watt- h r
Q
or
cc (STP) F2
O r
2.47~10~ h r - g
wa t t - h r
62 mole s a l t
cc(STP)F,
o r 1.15~10~
hr-mole s a l t
LiF-BeF2-ZrF4-ThF4-UF4(6g.0-23.0-5.2-l.7-l.lmole
Molecular weight
=
46.5.
8).
RESULTS OF OTHER EXPERIMENTS
I n - P i l e Experiments1
The s e r i e s of i n - p i l e experiments which f i r s t drew a t t e n t i o n t o t h e
matter of f l u o r i n e e v o l u t i o n and l a t e r proved it t o be a low-temperature
phenomenon a l s o produced q u a n t i t a t i v e i n f o r m a t i o n on y i e l d s and temperat u r e e f f e c t s on recombination.
There were c l u e s i n experiments 47-1, 47-2,
and 47-3 t h a t were l a t e r
recognized as e f f e c t s of f l u o r i n e e v o l u t i o n , b u t a b o u t t h e o n l y q u a n t i t a t i v e i n f o r m a t i o n on t h i s s u b j e c t was t h a t CF, y i e l d s were much lower i n
c a p s u l e s i n which t h e s a l t had cooled and f r o z e n more slowly.
When t h e c a p s u l e s from experiment 47-4 were punctured a f t e r exposure
and cooling, f l u o r i n e was i d e n t i f i e d and t h e equipment was r e v i s e d t o
a l l o w measurement of t h e amounts i n t h e c a p s u l e s .
P r e s s u r e s observed i n
t h e c a p s u l e s ranged as h i g h as 50 atmospheres of F2 and a t e n t h as much
CF,.
On t h e assumption t h a t h a l f of t h e decay energy r e l e a s e d d u r i n g t h e
95-day c o o l i n g p e r i o d was absorbed i n t h e salt, it was c a l c u l a t e d t h a t a
G v a l u e of 0.035 molecules/100 e v would have produced t h e f l u o r i n e observed
i n t h e maximum c a s e .
Other c a p s u l e s showed l e s s F2, w i t h e x t r e m e l y wide
v a r i a t i o n s b o t h i n t h e amounts of F2 and t h e r a t i o CF,/F2,
i n d i c a t i n g the
p r e s e n c e of u n i d e n t i f i e d f a c t o r s a f f e c t i n g t h e n e t y i e l d of f l u o r i n e .
Experiment 47-5, designed a f t e r t h e o b s e r v a t i o n of CF, i n t h e 47-3
capsules, i n c l u d e d two c a p s u l e s w i t h p r o v i s i o n s for g a s sampling and
p r e s s u r e measurement.
During i n t e r v a l s when t h e MTR was s h u t down, t h e
c a p s u l e s were cooled t o a b o u t 4OoC, and, a f t e r v a r i a b l e i n d u c t i o n p e r i o d s ,
an accumulation of g a s i n t h e c a p s u l e s was n o t e d by p r e s s u r e measurements.
The accumulating g a s was found t o b e F2 and t o be r e l e a s e d from t h e f r o z e n
fuel at
v a l u e s (molecules of F2 p e r 100 e v of absorbed energy) from
a b o u t 0.005 t o 0.031,
a l t h o u g h on o c c a s i o n t h e i n d u c t i o n p e r i o d p e r s i s t e d
throughout t h e shutdown.
No c o r r e l a t i o n between c a p s u l e power d e n s i t y
j u s t b e f o r e shutdown and e i t h e r GF2 v a l u e s o r d u r a t i o n of i n d u c t i o n p e r i o d s
was observed.
There were seven shutdowns of s u f f i c i e n t d u r a t i o n f o r t h e
e f f e c t s t o b e noted.
S h o r t (4-hr) p e r i o d s a t low power i n which f i s s i o n i n g
16
continued a t some r a t e w i t h t h e s a l t a t t e m p e r a t u r e s between
85 and 325°C
I
produced no d e t e c t a b l e accumulation of gas.
The s i x c a p s u l e s of experiment 47-5 were moved q u i c k l y from t h e MTR
t o an ORNL h o t c e l l where p r e s s u r e s were monitored t o determine f l u o r i n e
e v o l u t i o n i n t h e two v e n t e d c a p s u l e s .
one of which had o p e r a t e d a t
are shown i n F i g . 5 .
points.5
R e s u l t s f o r t h e s e two c a p s u l e s ,
65 watts/cm3
and t h e o t h e r a t
35 watts/cm3,
A n a l y s i s of t h e d a t a b r o u g h t o u t t h e f o l l o w i n g
The e v o l u t i o n r a t e s c a l c u l a t e d from p r e s s u r e d e r i v a t i v e s between
11 and 31 days a t
36"c and 50°C were p r o p o r t i o n a l t o t h e power d e n s i t y i n
t h e c a p s u l e s and correspond t o a y i e l d of 0.020 molecules F2/100 ev.
Ex-
periments a t v a r i o u s temperatures showed t h a t e v o l u t i o n was s u p p r e s s e d
when t h e s a l t was e i t h e r v e r y c o l d (-70°C)
o r moderately w a r m (80"~).
B u r s t s of F2 o c c u r r e d immediately a f t e r t h e temperature was s t e p p e d up.
These d a t a s u g g e s t t h a t t h e r a t e of e v o l u t i o n of F2 i s c o n t r o l l e d a t low
temperatures by r a t e s of d i f f u s i o n of r a d i o l y t i c s p e c i e s w i t h i n t h e s o l i d ,
and a t h i g h e r temperatures by a back r e a c t i o n whose r a t e i s s t r o n g l y temp e r a t u r e dependent.
L a t e r ( a f t e r day 1.13) t h e e f f e c t of F2 p r e s s u r e was
e x p l o r e d b y adding F2 t o t h e c a p s u l e s .
Above 50°C t h e r e were pronounced
d e c r e a s e s i n e v o l u t i o n a t h i g h e r p r e s s u r e s , b u t some e x t r a n e o u s e f f e c t s ,
presumed t o be changing c o n d i t i o n of t h e s a l t s u r f a c e , d i d n o t p e r m i t
d e r i v a t i o n of a q u a n t i t a t i v e p r e s s u r e r e l a t i o n .
Also exposed i n
47-5 were 4
s e a l e d c a p s u l e s of 3 d i f f e r e n t geometries.
The g a s spaces i n t h e s e c a p s u l e s , a f t e r
5
months cooling, y i e l d e d v e r y
d i f f e r e n t q u a n t i t i e s of F2 and CF,;
one gave 39 cm3 of Fz and
CF4, a n o t h e r gave 2.5 cm3 of F2 and
0.6
s u l e s y i e l d e d none of e i t h e r g a s .
70 cm3
of
cm3 of CF4, and two s m a l l e r cap-
The most p l a u s i b l e r e a s o n f o r t h e d i f -
f e r e n c e s seemed t o be t h e l a r g e d i f f e r e n c e s i n c o o l i n g rates among t h e
c a p s u l e s and consequent d i f f e r e n c e s i n c r y s t a l l i t e s i z e s and d e g r e e s of
s t r e s s i n t r o d u c e d i n t o t h e c r y s t a l l i t e , w i t h slower c o o l i n g r e s u l t i n g i n
less g a s e v o l u t i o n .
I n t h e f i n a l experiment,
47-6, t h e s a l t
i n t h e c a p s u l e s was k e p t
molten d u r i n g exposure and no f l u o r i n e e v o l u t i o n was d e t e c t e d .
After re-
moval, t h e c a p s u l e s were q u i c k l y disassembled f o r i n s p e c t i o n s o no f l u o r i n e
e v o l u t i o n r a t e was measured.
1
ORNL-DWG 63-598R
44
I
.\
42
I
I
I
I
I
I
I
I
60
70
80
90
\
\
40
\CALCULATED YIELD FOR HIGH-POWER
CAPSULE WITH GFz=0.02
\
r,
8
0
al
a
LN
b
m
6
E
0
2 4
2
0
-2
0
40
20
30
40
50
4 00
COOLING TIME (days)
F i g . 5.
P o s t i r r a d i a t i o n F l u o r i n e Release i n MTR-47-5 Capsules
X-Rag I r r a d i a t i o n s ’
S o f t x - r a y i r r a d i a t i o n of a s o l i d m i x t u r e similar t o t h e MSRE f u e l
gave evidence of r a d i o l y t i c decomposition w i t h y i e l d s of v o l a t i l e f l u o r i n e
compounds e q u i v a l e n t t o G F ~(moles of F2 p e r 100 e v absorbed) v a l u e s
r a n g i n g from 0.0006 t o 0.04.
f ied, b u t , g e n e r a l l y ,
fluoride.
I n some c a s e s e l e m e n t a l f l u o r i n e was i d e n t i -
t h e p r o d u c t s were carbon t e t r a f l u o r i d e and c a r b o n y l
P r e f l u o r i n a t i o n of t h e s a l t removed c a r b o n - c o n t a i n i n g i m p u r i t i e s
and encouraged l i b e r a t i o n of e l e m e n t a l f l u o r i n e .
Fine p a r t i c l e s l i b e r a t e d
v o l a t i l e f l u o r i n e - c o n t a i n i n g p r o d u c t s a t a b o u t t e n times t h e r a t e from
coarse p a r t i c l e s .
The compound 6LiF-BeF2eZrF4, one of t h e complex com-
pounds which c r y s t a l l i z e from t h e MSRE f u e l , decomposed w i t h an e q u i v a l e n t
GF2 of a b o u t 0.02.
P r e f l u o r i n a t e d thorium f l u o r i d e l i b e r a t e d e l e m e n t a l
f l u o r i n e a t r a t e s of a b o u t 0.005 molecule p e r 100 ev.
Neither l i t h i u m nor
zirconium f l u o r i d e s gave any evidence of r a d i o l y s i s .
F a s t E l e c t r o n Bombardment6
A Van de Graaf machine was used t o bombard s a l t a t 25
-
30°C,
He-F, atmosphere, i n an i r r a d i a t i o n c e l l equipped f o r g a s a n a l y s i s .
under a
Yields
from s i m u l a t e d MSFE f u e l s a l t v a r i e d w i t h dose r a t e and t o t a l dose, exh i b i t i n g maxima a b o u t 0.02 molecules F&00
ev.
Bombardment of LiF showed
no e v o l u t i o n of f l u o r i n e , b u t a n uptake t h a t was induced b y t h e i r r a d i a t i o n .
Discussion
The i n - p i l e c a p s u l e s were n o t a b l e f o r t h e wide v a r i a t i o n s i n f l u o r i n e
y i e l d s , w i t h some c a p s u l e s y i e l d i n g no f l u o r i n e ( t h e small c a p s u l e s i n
47-5) and o t h e r s producing up t o 0.035 molecules/100 ev.
The evidence
seems t o be t h a t slow f r e e z i n g can g r e a t l y reduce subsequent f l u o r i n e evol u t i o n even t o z e r o .
There i s some s u g g e s t i o n i n a comparison of a l l t h e d i f f e r e n t e x p e r i ments t h a t e l e c t r o n s or f i s s i o n - p r o d u c t b e t a p a r t i c l e s produce l e s s f l u o r i n e
t h a n do gamma r a y s p e r u n i t of absorbed energy (perhaps because of d i f f e r e n c e s i n d e n s i t y of d i s l o c a t i o n s a l o n g t h e p a r t i c l e t r a c k s ) .
t h e ‘ O C o gamma r a y s produced FZ w i t h an average G v a l u e of
0.045
Whereas
W
molecules/100 ev, t h e b e s t v a l u e of y i e l d from i r r a d i a t i o n b y i n c l u d e d
f i s s i o n p r o d u c t s (measured i n t h e r a p i d l y cooled 47-5 c a p s u l e s ) i s a b o u t
0.020 molecules/100.
Recombination ( s u p p r e s s i o n of e v o l u t i o n ) was s i g n i f i c a n t i n the
c a p s u l e s a t t e m p e r a t u r e s from
69 t o 87"c,
47-5
a range i n which t h e recombi-
n a t i o n f a c t o r d e r i v e d From the 6oCo experiment would be q u i t e low.
I n c a l c u l a t i o n s f o r MSF33 o r MSBR s a l t , f r o z e n s l o w l y i n r e l a t i v e l y
l a r g e tanks, and i r r a d i a t e d by c o n t a i n e d f i s s i o n p r o d u c t s , it seems
r e a s o n a b l e t o u s e the G v a l u e of 0.02 molecules/100 e v observed i n the
47-5 c a p s u l e s .
T h i s i s p r o b a b l y c o n s e r v a t i v e because t h e s a l t i n t h e
l a r g e r v e s s e l s w i l l c o o l and f r e e z e even more slowly t h a n the s l o w e s t
cooled c a p s u l e s , which showed no f l u o r i n e e v o l u t i o n .
There may be some
tendency toward a h i g h e r G because a g r e a t e r f r a c t i o n of t h e gamma r a y s
w i l l be absorbed i n t h e l a r g e b o d i e s of salt, b u t t h i s i s p r o b a b l y n o t
as i m p o r t a n t as t h e c o o l i n g r a t e e f f e c t .
I n any case t h e v a l u e of 0.02
i s p r o b a b l y w i t h i n a f a c t o r of two.
Use of t h e recombination f a c t o r from t h e 6oCo experiment i s p r o b a b l y
a l s o c o n s e r v a t i v e , based on t h e r e s u l t s of t h e 47-5 experiment.
STORAGE AND DISPOSAL OF MSRF SALT
S h o r t l y a f t e r t h e n u c l e a r o p e r a t i o n of t h e MSRE was concluded on
December 12,
1969, t h e
f u e l s a l t was d i v i d e d between t h e two @-inch I D
d r a i n t a n k s and t h e heat was t u r n e d off.7
I n the i n s u l a t e d t a n k s t h e
s a l t cooled v e r y slowly, and it was 22 days b e f o r e thermocouples a t t h e
c e n t e r s of the t a n k s i n d i c a t e d t h a t t h e s a l t t h e r e had reached t h e s o l i d u s
temperature
(6620~). A
few days l a t e r , the t a n k h e a t e r s were t u r n e d on
a t low s e t t i n g s t o h o l d t h e s a l t t e m p e r a t u r e s between 450 and
650"~.The
same was done w i t h t h e f l u s h s a l t .
I n p l a n n i n g f o r t h e u l t i m a t e d i s p o s a l of t h e M W salts and the i n t e r i m
s u r v e i l l a n c e , it i s n e c e s s a r y t o c o n s i d e r r a d i o l y t i c p r o d u c t i o n of f l u o r i n e
and t h e measures needed t o c o n t r o l f l u o r i n e e v o l u t i o n from t h e s a l t .
There
would be some advantage i n b e i n g a b l e t o t u r n o f f the h e a t e r s on t h e salt
tanks.
20
Energy Sources
During o p e r a t i o n of t h e MSRE, gaseous f i s s i o n p r o d u c t s (Xe, K r ) were
s t r i p p e d from t h e f u e l on a s h o r t c y c l e , noble m e t a l s (Nb, Mo, Ru, Te)
soon d e p o s i t e d on s u r f a c e s , and t h e o t h e r f i s s i o n p r o d u c t s remained i n t h e
f u e l salt.
Each time t h e f u e l loop was f l u s h e d , a b o u t 0.4% of t h e f i s s i o n
p r o d u c t s i n t h e f u e l s a l t became mixed i n t o t h e f l u s h s a l t .
only
T h i s was done
9 times d u r i n g t h e 4 y e a r s of power o p e r a t i o n , s o t h e a c t i v i t y i n t h e
f u e l s a l t was n o t diminished s i g n i f i c a n t l y by t h i s e f f e c t .
The i n v e n t o r i e s of f i s s i o n p r o d u c t s and a c t i n i d e s i n t h e MSRE s a l t
were computed b y M. J. B e l l , u s i n g t h e ORIGEN code and t a k i n g i n t o a c c o u n t
g a s s t r i p p i n g and t h e o p e r a t i n g h i s t o r y of t h e r e a c t o r . 8
Figure
6 shows
t h e c u r i e s of f i s s i o n p r o d u c t s remaining as a f u n c t i o n of t i m e a f t e r t h e
end of n u c l e a r o p e r a t i o n on December 12, 1969. The c a l c u l a t e d a c t i v i t y
of t h e a c t i n i d e s (mainly t h e c h a i n descending from 23%) amounts t o
2.5 x lo3 C i a t 384 d, d e c r e a s i n g v e r y slowly t o 2.3 x lo3 C i a t 1845 d.
The energy s o u r c e s r e p r e s e n t e d by t h e f i s s i o n p r o d u c t s and heavy n u c l i d e s
i n t h e MSRE s a l t a r e shown i n F i g . 7.
I n t h e 49-inch I D s a l t t a n k s
p r a c t i c a l l y a l l of t h i s energy w i l l b e absorbed.
lo5
There i s 4647 kg (1.06 x
moles) of f u e l s a l t , s o t h e energy source p e r mole i s 0.94 x
t h e t o t a l source shown i n F i g . 7.
times
A s of J a n u a r y 1, 1971 (when it would b e
convenient t o be a b l e t o t u r n o f f t h e h e a t on t h e t a n k s ) t h e source i n t e n s i t y would be 0.0069 watts/mole.
On January 1, 1975, which i s perhaps
as soon as t h e permanent d i s p o s a l might be made, t h e source would amount
t o 0.00195 watts/mole
.
Temperature f o r I n t e r n a l Recombination
The p r o d u c t i o n of F2 w i t h i n t h e MSRF: s a l t i s p r o p o r t i o n a l t o t h e
absorbed energy.
It would appear r e a s o n a b l e t o estimate t h e y i e l d on t h e
b a s i s of v a l u e s observed i n t h e i n p i l e c a p s u l e s , where t h e s a l t composition
*
was v e r y similar t o t h a t of t h e f i n a l MSRE f u e l
*The
and t h e i r r a d i a t i o n was
composition of t h e MSRE f u e l a t t h e f i n a l shutdown, based on
on a v e r a g e s of f u e l samples was LiF-BeF2-ZrF4-UF4 (64.2-30.7-5.0-0.14
mole 8 ) . The molecular weight i s 43.7.
21
ORNL DWG. 70-12908
Fig. 6. Fission Product Inventories in MSRE Salt
22
O W L DUG. 70-12909
IN71
W
V
(Y
3
0
v)
\/I
/72
1/1/73
1/1/74
1/1/75
s i m i l a r l y from i n c l u d e d f i s s i o n p r o d u c t s .
The most p r e c i s e l y measured
v a l u e was 0.020 molecules/100 ev, o b t a i n e d by t r a c k i n g t h e f l u o r i n e evol u t i o n from t h e two v e n t e d c a p s u l e s i n experiment 47-5.
The MSRE f u e l
f r o z e v e r y much more slowly than d i d t h e s a l t i n t h e s e c a p s u l e s and t h e
evidence seems t o i n d i c a t e lower y i e l d s from slower-cooled s a l t , s o use
of G = 0.020 p r o b a b l y i s a c o n s e r v a t i v e l y h i g h v a l u e f o r t h e y i e l d i n t h e
MSRE.
( T h i s i s n o t c e r t a i n , however, because of t h e unknown e f f e c t s of
t a n k s i z e , degree of s a l t cracking, e t c , ,
on escape of f l u o r i n e . )
Assuming
a y i e l d of 0.020 molecules/100 ev, t h e p r o d u c t i o n w i t h i n t h e s a l t would
amount t o 0.17 S cc(STP)/hr-mole where S i s t h e energy a b s o r p t i o n r a t e i n
watts/mole.
The recombination of f l u o r i n e i n t h e s a l t can b e e s t i m a t e d by t h e
r e l a t i o n d e r i v e d from t h e 6oCo experiment.
When t h e p r o d u c t i o n i s e q u a t e d
t o t h e e x p r e s s i o n f o r t h e recombination r a t e as a f u n c t i o n of temperature,
the r e s u l t i s
s =
1.15 x lo9 e0,17
9710
T
-
watts
mole
T h i s i s t h e r e l a t i o n between S and t h e temper>ture a t which a l l t h e
f l u o r i n e would j u s t be recombined,
I f one t a k e s S f o r t h e MSRF, f u e l from F i g .
7 and u s e s t h e f o r e g o i n g
r e l a t i o n between S and T t o compute temperature, one f i n d s t h a t t h e r e q u i r e d temperature d e c r e a s e s v e r y slowly from 173°F i n January,
1971 t o
145°F i n January, 1975. The r e q u i r e d temperatures would be h i g h e r by o n l y
15°F i f one were a r b i t r a r i l y t o assume twice t h e f l u o r i n e y i e l d ( G = 0.04
i n s t e a d of O , O ~molecules/100 e v ) .
I n d u c t i o n P e r i o d and F l u o r i n e Release
If t h e MSm s a l t were somehow cooled below t h e p c i n t of complete i n -
t e r n a l recombination of t h e F2, it would p r o b a b l y s t i l l be a v e r y long
t i m e b e f o r e any F2 was r e l e a s e d .
If t h e i n d u c t i o n p e r i o d were
6,6 x lo6 w a t t - h r
January- 1, 1971, i t
mole (as i n t h e 6oCo experiment), t h i s would amount t o
i n t h e MSRE f u e l s a l t .
If t h e s a l t were c h i l l e d on
62 w a t t - h r /
24
I
would be over 30 months b e f o r e t h i s much energy was absorbed.
i n d u c t i o n p e r i o d began on J a n u a r y 1,
1975, i t
If t h e
would be a t l e a s t 45 months
b e f o r e t h e absorbed energy amounted t o 62 watt-hr/mole.
F2 p r o d u c t i o n i n t h e M S R E f u e l s a l t on J a n u a r y 1, 1971 (assuming
0.02 molecules/100 e v ) w i l l be 0.17 x 737 = 125 cc(STP)/hr.
If t h e r e
The
G =
were no recombination and a l l t h e F2 accumulated i n t h e g a s space i n t h e
f u e l d r a i n tanks, t h e r a t e of p r e s s u r e i n c r e a s e would b e 0.12 psi/week.
(The volume of t h e two t a n k s i s 160 ft3, of which
f t 3 i s f i l l e d with
I, 1975 t h e p r o d u c t i o n r a t e would be down t o 35 cc(STP)/hr.
t h e s a l t were p u t i n cans w i t h 10% f r e e volume and a l l t h e F2 produced
salt.)
If
66
By J a n u a r y
accumulated i n t h e g a s space, t h e r a t e of p r e s s u r e rise a t t h a t t i m e would
be 0.42 psi/week.
Discussion
The f i g u r e s g e n e r a t e d above p r o v i d e a b a s i s f o r p l a n n i n g t h e s u r v e i l l a n c e and d i s p o s a l of t h e MSRE f u e l s a l t .
T h i s planning, which t a k e s
i n t o a c c o u n t many c o n s i d e r a t i o n s b e s i d e s f l u o r i n e e v o l u t i o n , i s c u r r e n t l y
underway and w i l l be r e p o r t e d s e p a r a t e l y .
One simple mode of o p e r a t i o n
d u r i n g t h e s u r v e i l l a n c e p e r i o d , t h a t a p p e a r s f e a s i b l e from t h e s t a n d p o i n t
of F2 p r o d u c t i o n and recombination, would b e t o h e a t t h e d r a i n t a n k s o n l y
once a y e a r ( a t t h e time of t h e a n n u a l system t e s t s ) t o a temperature
( s a y 300°F) a t which a l l t h e F2 would c e r t a i n l y be recombined.
There are
some d a t a which i n d i c a t e t h e t a n k s might n o t c o o l below t h e t h r e s h o l d
temperature i n one y e a r w i t h o u t e x t e r n a l h e a t .
But even i f it did, t h e
e s t i m a t e d i n d u c t i o n p e r i o d i s much l o n g e r t h a n a y e a r , so p r o b a b l y no F2
would b e r e l e a s e d i n t h e i n t e r v a l between h e a t i n g .
25
v
DEALING WITH SALT FROM LARGE MOLTEN-SALT REACTORS
I n one scheme of o p e r a t i o n of m o l t e n - s a l t c o n v e r t e r r e a c t o r s , t h e
8
f u e l s a l t would be d i s c a r d e d p e r i o d i c a l l y ( a f t e r t h e uranium had been
s t r i p p e d from i t ) . A f t e r b e i n g h e l d f o r a while i n l a r g e t a n k s w i t h
i n t e r n a l c o o l i n g c a p a b i l i t i e s , t h e s a l t would be p u t i n t o simple cans
and allowed t o f r e e z e .
I n t e r n a l h e a t i n g by t h e f i s s i o n p r o d u c t s would,
of course, keep t h e s a l t above t h e ambient temperature and t h e s a l t could
n o t be canned t o o soon a f t e r o p e r a t i o n w i t h o u t c r e a t i n g a problem of
keeping t h e cans from o v e r h e a t i n g .
Later, a f t e r t h e h e a t source had d i -
minished, t h e problem would change t o one of keeping t h e s a l t warm enough
t o p r e v e n t f l u o r i n e e v o l u t i o n due t o r a d i o l y s i s of t h e f r o z e n s a l t .
Energy Source
T y p i c a l MSR power d e n s i t i e s d u r i n g o p e r a t i o n f a l l i n t h e range from
a b o u t 1.0 t o 1.5 M w ( t ) / f t 3
of s a l t .
A few minutes a f t e r shutdown of t h e
f i s s i o n c h a i n r e a c t i o n , t h e energy from decay of f i s s i o n p r o d u c t s i n t h e
s a l t i s on t h e o r d e r of 10 kw/ft3.
By t h e t i m e t h e s a l t could b e p r o -
c e s s e d and r e a d y t o p u t i n t o s t o r a g e cans ( s a y
6 weeks a f t e r shutdown),
t h e energy source would be down t o around 500 watts/ft3.
be taken as t h e h i g h end of t h e range t o be considered.
pends on d e t a i l e d p l a n s f o r s a l t s t o r a g e and d i s p o s a l .
This then w i l l
The low end deIf t h e cans of
f l u o r i d e s a l t a r e t o be disposed of by b u r i a l i n a s a l t mine, an economic
a n a l y s i s of t h e r e l a t i o n between h e a t source and a l l o w a b l e spacing i n the
mine would p r o b a b l y d i c t a t e a c o o l i n g time of a t l e a s t a y e a r ,
A t one
y e a r t h e h e a t source i n M S R s a l t would be down t o a b o u t 60 watts/ft3.
It i s n e c e s s a r y t o c o n s i d e r much lower energy sources, however, because
f o r some r e a s o n it might b e d e s i r a b l e t o s t o r e t h e s a l t f o r much l o n g e r
than a year.
Heat T r a n s f e r and Temperatures
The temperature of t h e canned s a l t w i l l depend on t h e h e a t source,
t h e dimensions of t h e can, and t h e ambient c o n d i t i o n s .
t e n t a t i v e l y c o n s i d e r e d i s 2 - f t d i a by 1 0 - f t long.
The s i z e can
When f i r s t loaded,
26
t h e cans might b e l e f t b a r e , r a d i a t i n g t o r e l a t i v e l y c o o l s u r f a c e s i n
some k i n d of s t o r a g e v a u l t . Later, i f n e c e s s a r y t o p r e v e n t f l u o r i n e evol u t i o n , t h e cans presumably could be s e t i n t o i n s u l a t e d o r h e a t e d enclosures,
Internal Distribution
The r a d i a l temperature d i s t r i b u t i o n w i t h i n a long c y l i n d e r i n which
h e a t t r a n s f e r i s o n l y by conduction (as i t would be i f t h e s a l t were
frozen) i s
For molten MSBR s a l t , k i s a b o u t 0.7 Btu/hr-ft-'F.
The c o n d u c t i v i t y of
f r o z e n s a l t i n c r e a s e s r a p i d l y as t h e temperature i s 1 0 w e r e d . ~ For s i m p l i c i t y , l e t us use a c o n s t a n t v a l u e of k =
c e n t e r l i n e temperature, Tc,
T,
0.7.
Then f o r R = 1 f t , t h e
i s given by
=
TR
+
1.22 S
where t h e temperatures are i n OF and S i s i n watts/ft3.
If t h e s a l t were
molten, convective c u r r e n t s would reduce t h e temperature g r a d i e n t w i t h i n
the s a l t .
Surface of Bare C y l i n d e r
Consider t h e case where t h e can i s exposed t o t h e a i r .
A convective
f i l m c o e f f i c i e n t can be e s t i m a t e d from a convenient alignment c h a r t f o r
n a t u r a l convection from v e r t i c a l s u r f a c e s , g i v e n b y McAdams (Ref. 10,
p . 1-75.) Assuming a i r a t 1 atmosphere and 100°F, t h e e s t i m a t e d h e a t f l u x
due t o convection v a r i e s w i t h s u r f a c e temperature as i n d i c a t e d i n Table 4.
Heat loss by r a d i a t i o n w i l l be q u i t e i m p o r t a n t i f t h e can s e e s c o o l s u r faces.
If t h e r e a r e "black" s u r f a c e s a t T2
t r a n s f e r r e d by r a d i a t i o n i s given b y ( R e f .
qi-2
=
0.171 c1
O R
i n a l l directions the heat
10, p .
Tl
100
65).
T2
- (%)*I
Assuming s1 = 0.5 ( a b o u t r i g h t f o r o x i d i z e d n i c k e l - a l l o y s u r f a c e s ) and
T2
=
560"~(lOO°F),
t h e h e a t f l u x due t o r a d i a t i o n i s as shown i n Table I t .
27
Table
4
Heat Loss from V e r t i c a l Surface Exposed t o
A i r and Cool S u r f a c e s a t lOOOF
Surface T
( OF)
Heat Flux ( B t u / h r - f t 2 )
Convection
Radiation
To t a l
1-50
36
200
90
300
200
400
230
400
380
430
780
500
560
640
1200
34
80
70
1-70
For a l o n g 2 - f t diameter c y l i n d e r , t h e h e a t f l u x a t t h e s u r f a c e i s
r e l a t e d t o t h e i n t e r n a l h e a t source by
9 A
-
1.71 s
where q/A i s i n B t u / h r - f t 2 and S i s i n watts/ft3.
This r e l a t i o n , the
numbers i n Table 1 and t h e r e l a t i o n g i v e n above f o r c e n t e r l i n e temperat u r e combine t o g i v e s a l t temperatures i n a b a r e , r a d i a t i n g can as a
f u n c t i o n of S as shown i n F i g . 8.
S u r f a c e of I n s u l a t e d C y l i n d e r
When measures have t o be t a k e n t o keep t h e cans of s a l t warm, t h e r e
are s e v e r a l t h i n g s t h a t might be done.
It i s e v i d e n t from Table
4 that
simply c u t t i n g o f f t h e r a d i a n t h e a t l o s s would a l m o s t double t h e AT between t h e can and t h e a i r .
( A c t u a l l y a l a y e r of r e f l e c t i v e material
would p r o b a b l y a l s o c u t down on convection.)
Later, as more e f f i c i e n t
i n s u l a t i o n became necessary, it would be simple t o s e t s e v e r a l cans t o g e t h e r i n a i n s u l a t e d box.
To g e t a f e e l f o r t h e amount of i n s u l a t i o n
r e q u i r e d , c o n s i d e r a s i n g l e can, w i t h a n o n - r a d i a t i n g l a y e r of i n s u l a t i o n
28
Fi- g . 8.
Temperatures i n a 2-ft Diameter Can of S a l t Exposed t o lOOOF
Surroundings and the Temperature Required t o P r e v e n t F l u o r i n e Release
immediately around it.
For any t h i c k n e s s , x,,l e s s t h a n t h e r a d i u s of t h e
can, R, t h e AT between t h e can s u r f a c e and t h e o u t s i d e s u r f a c e of t h e
i n s u l a t i o n i s c l o s e l y approximated b y
L e t u s make c a l c u l a t i o n s f o r a long, 2 - f t d i a m e t e r can, c l o s e l y surrounded
b y i n s u l a t i o n w i t h k = 0.03 Btu/hr-ft-OF,
which does n o t r a d i a t e , b u t
g i v e s up h e a t by thermal convection t o a i r a t 100OF.
With t h e convective
f i l m c o e f f i c i e n t e v a l u a t e d as i n d i c a t e d i n t h e p r e c e d i n g s e c t i o n and t h e
through t h e i n s u l a t i o n given by t h e above r e l a t i o n , one c a l c u l a t e s t h e
t e m p e r a t u r e s as a f u n c t i o n of S shown i n F i g .
9.
Can Imbedded i n a Salt Mine
If t h e cans of MSR s a l t are disposed of i n t h e proposed n a t i o n a l
disposal facility,"
t h e y would be p u t i n t o h o l e s b o r e d i n r o c k s a l t ( N a C 1 )
and covered w i t h crushed s a l t .
i n t h e cans.
After b u r i a l ,
t h e N a C l w i l l flow and s e a l
The temperature of t h e s a l t bed i n i t i a l l y w i l l b e a b o u t TOOF,
s o i f t h e r e i s good thermal c o n t a c t , t h e temperature i n t h e canned f l u o r i d e s a l t would be p u l l e d s o low t h a t f l u o r i n e would n o t be recombined
e f f e c t i v e l y , a t l e a s t n o t f o r a while.
Some q u e s t i o n s t h a t a r i s e then
a r e "How f a s t and how f a r w i l l t h e s a l t bed temperature r i s e ? " and "Can
i n s u l a t i o n around each can be used e f f e c t i v e l y ? "
The answer t o t h e f i r s t q u e s t i o n depends on t h e i n t e n s i t y of t h e h e a t
source, t h e s p a c i n g between cans and t h e e x t e n t of t h e b u r i e d a r r a y .
Current planning f o r the d i s p o s a l f a c i l i t y a n t i c i p a t e s allowable s a l t
t e m p e r a t u r e s up t o 2OO0C, b u t i n t y p i c a l l a y o u t s t h e temperature t a k e s
a b o u t 3 y e a r s t o r i s e above 100°C ( R e f . 1 2 ) .
So t h e r e would p r o b a b l y b e
c o n s i d e r a b l e f l u o r i n e e v o l u t i o n from MSR s a l t i n b a r e cans f o r t h e f i r s t
few y e a r s a t least.
The q u e s t i o n of i n s u l a t i o n may be wroth i n v e s t i g a t i n g .
One f a c t o r
t o be c o n s i d e r e d i s t h e e f f e c t of t h e b r i n e i n c l u s i o n s i n t h e s a l t t h a t
w i l l m i g r a t e up t h e thermal g r a d i e n t t o t h e h e a t source.
ProSably more p r a c t i c a l would be t o a n t i c i p a t e f l u o r i n e g e n e r a t i o n
and p o s s i b l e escape from t h e cans.
The r a t e s of r e l e a s e would n o t be
g r e a t i n any case, and p r o b a b l y would n o t c r e a t e a h a z a r d .
F l u o r i n e Yield and I n d u c t i o n P e r i o d
The f l u o r i n e p r o d u c t i o n i n t h e s a l t w i l l be p r o p o r t i o n a l t o t h e
energy source, S.
As d i s c u s s e d i n preceding c h a p t e r s a r e a s o n a b l e v a l u e
f o r t h e f l u o r i n e y i e l d i s 0.020 molecules F2/100 e v of absorbed energy.
T h i s i s e q u i v a l e n t t o 0.17 cc/(gTP)/watt/hr.
It i s i n t e r e s t i n g t o c o n s i d e r t h e r a t e of p r e s s u r e i n c r e a s e t h a t
might occur i n a can of s a l t i f t h e temperature were such t h a t t h e r e was
no recombination so t h a t a l l f l u o r i n e was going i n t o t h e g a s phase.
Assume an energy s o u r c e of 100 watts/ft3.
(With more i n t e n s e s o u r c e s
even a b a r e can of s a l t would probably b e w a r m enough t o recombine some
of t h e F2.) Assume a l s o t h a t t h e g a s space i n t h e can i s 0 . 1 a s l a r g e
as t h e s a l t volume.
Then
c c gas
cc s a l t
io4 cc
2.83
ft3
Obviously t h e f o r e g o i n g s i t u a t i o n could be t o l e r a t e d only t e m p o r a r i l y ,
s o t h e q u e s t i o n of t h e i n d u c t i o n p e r i o d a r i s e s .
The amount of energy t h a t
might be absorbed b e f o r e f l u o r i n e b e g i n s t o be evolved i s around 62
wat-hr/mole
s a l t (based on the 6oCo e x p e r i m e n t s ) .
i s a b o u t 1500 moles/ft3.
ft3
MSBR s a l t molar d e n s i t y
If t h e energy source i n t h e s a l t were 100 watts/
(0.067 watts/mole), t h e n f o l l o w i n g a r e d u c t i o n i n s a l t temperature
from t h e range of complete recombination, t h e i n t e r v a l b e f o r e f l u o r i n e
e v o l u a t i o n began would be roughly
5
to
6 weeks.
G2 w a t t - h r
at
=
0.067
mole
watt
mole
=
930 h r
32
Temperature f o r Zero Release of F l u o r i n e
The r a t e of f l u o r i n e recombination i n M S R s a l t can b e c a l c u l a t e d
from t h e r e s u l t s of t h e 6oCo experiment.
The r a t e of recombination when
t h e c o n c e n t r a t i o n of f l u o r i n e i n t h e s a l t i s a t t h e t h r e s h o l d of evolution is
K
=
lo9
1.15 x
where T i s i n degrees Kelvin.
x 1500 e
- 9710
T
cc(sTP)
h r - f t3
The p r o d u c t i o n i n t h e s a l t ( c o r r e s p o n d i n g
t o G = 0.02) i s
P
where S i s i n watts/ft3.
=
0.17 s
c c ( STP)
h r - f t3
Equating P and K g i v e s a r e l a t i o n between T
and t h e maximum v a l u e of S a t which a l l t h e f l u o r i n e would be recombined
internally.
S
=
1.02 x
lo1'
e
- 9710
watt
T
ft3
T h i s r e l a t i o n s h i p i s r e p r e s e n t e d by t h e dashed curve superimposed on t h e
c a l c u l a t e d s a l t temperatures i n F i g s . 8 and
9.
Any combination of tem-
p e r a t u r e and absorbed energy source below and t o t h e r i g h t of t h e curve
would r e s u l t i n f l u o r i n e r e l e a s e from t h e s a l t .
A t any p o i n t on t h e
o t h e r s i d e of t h e curve, t h e f l u o r i n e would a l l be recombined w i t h i n t h e
salt.
Discussion
The purpose of t h e f o r e g o i n g c a l c u l a t i o n s i s t o p r o v i d e a b a s i s f o r
c o n s i d e r i n g ways of s t o r i n g i r r a d i a t e d MSR s a l t .
For example, from F i g . 8
one could conclude t h a t s a l t could be p u t i n t o a 2 - f t diameter can one
month a f t e r r e a c t o r shutdown and, w i t h no c o o l i n g o t h e r t h a n n a t u r a l conv e c t i o n t o 1 0 0 " a i r and r a d i a t i o n t o 100°F surroundings, it would n o t
33
W
overheat.
For t h e s e s t o r a g e c o n d i t i o n s , f l u o r i n e e v o l u t i o n might b e g i n
when t h e h e a t source had decayed t o about 1.50 watts/ft3, which would be
a b o u t 3 months a f t e r shutdown.
A r e f l e c t i v e l a y e r around t h e can would
keep t h e temperature h i g h enough o u t t o a b o u t a y e a r .
Then, as i n d i c a t e d
i n F i g . 9, an i n c h o r so of i n s u l a t i o n would keep t h e can warm enough f o r
s e v e r a l more y e a r s .
O f course, r a t h e r than changing t h e i n s u l a t i o n ,
it
might be s i m p l e r t o s t o r e t h e cans i n a c o n t r o l l e d - t e m p e r a t u r e e n c l o s u r e .
I n t h i s c a s e t h e c o n t r o l range would n o t need t o be wide:
100°F s u r -
roundings would keep t h e cans c o o l enough a t t h e b e g i n n i n g and 200°F
would keep t h e cans warm enough a t t h e end.
If t h e cans were t o be h a u l e d t o a d i s p o s a l s i t e s a y a y e a r a f t e r
shutdown, t h e r a d i a t i o n s h i e l d i n g around t h e can would p r o b a b l y keep t h e
s a l t warm enough t o p r e v e n t f l u o r i n e e v o l u t i o n .
But even i f t h e s a l t
were c h i l l e d a t t h i s time, it would probably be a few weeks b e f o r e
f l u o r i n e began t o be evolved.
It must be recognized t h a t t h e r e a r e c o n s i d e r a b l e u n c e r t a i n t i e s i n
t h e d a t a on f l u o r i n e e v o l u t i o n and t h e e x t r a p o l a t i o n from t h e c a p s u l e
experiments t o t h e MSR s a l t s t o r a g e c o n d i t i o n s .
be v a l u a b l e .
F u r t h e r r e s e a r c h would
N e v e r t h e l e s s i t i s c l e a r t h a t p r e v e n t i o n of f l u o r i n e evo-
l u t i o n from s t o r e d MSR s a l t w i l l n o t be v e r y d i f f i c u l t o r e x p e n s i v e ,
34
REFERENCES
1.
MSR Program Semiann. P r o g r . Rept. J u l y 31, 1964, ORNL-3708,
pp. 252
287.
2.
H. C. Savage, E. L. Compere, and J. M. Baker, Gamma I r r a d i a t i o n of
a Simulated MSRE F u e l Salt i n t h e S o l i d Phase, R e a c t o r Chem. Div.
Ann. Progr. Rept., J a n . 31, 1964, ORNL-3591, PP. 16 - 37.
3.
MSR Program Semiann. P r o g r . Rept., J a n . 31, 1964, ORNL-3626,
pp. 101 - 105.
4.
E. L. Compere, p r i v a t e communication, September
5.
F. F. Blankenship, S. S. Kirslis, and J. E. Savolainen, I n - P i l e Tests
of MSR M a t e r i a l s , Reactor Chem. Div. Ann. P r o g r . Rept., J a n . 31, 1964,
ORNL-3591, pp. 2 1 23.
-
1970.
-
6.
J. E. Baker and G. H. Jenks, F l u o r i n e E v o l u t i o n from S o l i d F l u o r i d e
Salts Under I r r a d i a t i o n s by Van de Graaf E l e c t r o n s , R e a c t o r Chem.
Div. Ann. P r o g r . Rept., J a n . 31, 1964, ORNL-3591, pp. 31 - 34.
7.
MSR Program Semiann. P r o g r . Rept.,
8.
M. J. B e l l , C a l c u l a t e d R a d i o a c t i v i t y of MSRF: F u e l Salt, USAEC Report
ORNL-"-2970,
(May 1970).
9.
MSR Program Semiann. Progr. Rept.,
PP. 89 - 93.
10.
W. H. McAdams, Heat Transmission,
11.
Aug. 31, 1969, OWL-4449,
3d ed., McGraw-Hill, New York, 1954.
S i t i n g of F u e l Reprocessing P l a n t s and Waste Management F a c i l i t i e s ,
OWL-4451 ( J u l y 1970) pp. 4 - 55
12.
Feb. 28, 1970, ORNL-4548, P O 3 -
-4 -
67.
R . L. Bradshaw, p r i v a t e communication, September 1970.
V
35
ORNL-TM-3144
INTERNAL
DISTRIBUTION
1. R. G. A f f e l
2. J. L. Anderson
3. C. F. Baes
4. S. E. B e a l l
5. M. Bender
6. E. S. B e t t i s
7. D. S. B i l l i n g t o n
8. F. F. Blankenship
9. J. L. Blomeke
10. E. G . Bohlmann
11. C. J. Borkowski
12. G. E. Boyd
13. R . L. Bradshaw
14. R . B. B r i g g s
15. R , H. Chapman
16. E. L. Compere
17. W. B. C o t t r e l l
18. F. L. C u l l e r
19. J. R . D i s t e f a n o
20. S. J. D i t t o
21. W. P. E a t h e r l y
22. J. R. Engel
23. D. E. Ferguson
24. L. M. F e r r i s
25. A. P. F r a a s
26. J. H. Frye
27. W. K. Furlong
28. W. R. Grimes
29. A. G. G r i n d e l l
30. R. H. Guymon
31-35. P. N. Haubenreich
36. He W. Hoffman
37. W. H. J o r d a n
38. P. R. Kasten
39. S. I. Kaplan
40. M. T. K e l l e y
41. J. J. Keyes
81-82.
83.
84-86.
87.
88.
42.
43
44.
45
46.
47
48.
49
9
50
51
52-53.
54
55
56 *
57
58
59.
9
60.
61-63.
64
65 *
66.
67
68.
69
e
70
71
72 e
73
74
75
76
77.
78
79.
80.
e
9
S. S. K i r s l i s
Kermit Laughon, AEC-OSR
R. B. Lindauer
M. I. Lundin
R . N. Won
H. G. MacPherson
R. E. MacPherson
W. C. McClain
H. E. McCoy
H. C. McCurdy
T. W. McIntosh, AEC-Washington
L. E . McNeese
A. S. Meyer
A. J. M i l l e r
R. L e Moore
J. P. Nichols
E. L. Nicholson
A. M. P e r r y
M. W. R o s e n t h a l
H. M. Roth, AFC-OR0
A. W. Savolainen
Dunlap S c o t t
M. Shaw, AEC-Washington
M. J. Skinner
W. L. Smalley, AEC-OR0
I. Spiewak
D, A. Sundberg
R. E. Thoma
D. B. Trauger
G . M. Watson
A. M. Weinberg
J. R. Weir
M. E. Whatley
J. C. White
G. D. Whitman
Gale Young
C e n t r a l Research L i b r a r y
Y-12 Document Reference S e c t i o n
Laboratory Records Department
Laboratory Records Department (RC)
ORNL P a t e n t O f f i c e
EXTERNAL
D ISITIBUTION
89-103. Division of Technical Information Extension (IYI'IE)
104. Laboratory and University Division, OR0