1
Isotope Separation Practice
1
JACOB
BIGELEISEN
Chemistry Department, Brookhaven National Laboratory, U p t o n , L o n g Island, N . Y . 11973
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A
survey
is presented
distinction
is made
scale isotope of laboratory rator,
thermal
are discussed. operated cussed
of isotope
between
separation
diffusion, Large
distillation,
scale
by their
Thermal by
in distillation
dual
temperature
sepaexchange
must be designed These
implications
to the
processes.
reflux can be achieved the
Examples
principles.
and exchange
are
and dis-
produc-
The cost of reflux
processes
in chemical and
A
laboratory
and chemical
processes
tion of heavy water by various
tems
for
by the electromagnetic
with cascade
and illustrated
operations
processes.
suitable
and large scale processes.
scale separation
in accord
separation
processes
is
stressed.
exchange
exchange
sys-
distillation
processes.
T n t e r e s t i n the s e p a r a t i o n of isotopes started as a scientific c u r i o s i t y . T h e A
q u e s t i o n arose as to w h e t h e r it w a s i n d e e d at a l l feasible or possible to
separate isotopes. (24),
A f t e r this q u e s t i o n was a n s w e r e d i n t h e affirmative
i t b e c a m e of interest to separate isotopes o n a l a b o r a t o r y scale f o r
use i n scientific research. separated isotopes.
A f e w examples s h o w the range of u t i l i t y of
D e u t e r i u m has a t t a i n e d w i d e s p r e a d use as a b i o -
c h e m i c a l a n d c h e m i c a l tracer. I t is n o w a b u n d a n t l y a v a i l a b l e a n d is u s e d as freely as a n y c h e a p c h e m i c a l reagent.
3
H e has o p e n e d u p a n e n t i r e l y
n e w field of research i n l o w t e m p e r a t u r e p h y s i c s a n d has i m p o r t a n t a p p l i cations i n the p r o d u c t i o n of temperatures b e l o w 1°K.
l 0
B , with a thermal
n e u t r o n cross section of 4,000 b a r n s , has f o u n d w i d e use i n n u c l e a r p a r ticle detectors—neutron
p r o p o r t i o n a l counters.
1
3
C s t i l l finds use as a
tracer, b u t i n recent years its most f r e q u e n t use has b e e n i n electron s p i n a n d n u c l e a r m a g n e t i c resonance
spectroscopy.
p o s i t i o n as the o n l y usable tracer for n i t r o g e n . 1
l r ,
l
s
N occupies a u n i q u e
O finds a p p l i c a t i o n as a
Present address: Univ. of Rochester, Rochester, N . Y. 14627.
1
In Isotope Effects in Chemical Processes; Spindel, William; Advances in Chemistry; American Chemical Society: Washington, DC, 1969.
2
ISOTOPE E F F E C T S IN C H E M I C A L PROCESSES
c h e m i c a l tracer, w h i l e the less a b u n d a n t isotope istotope w i t h a n u c l e a r m a g n e t i c m o m e n t .
1 7
1 7
0 is the o n l y o x y g e n
0 is scarce a n d m u c h sought
after for n u c l e a r m a g n e t i c resonance studies of o x y g e n
compounds.
S e p a r a t e d isotopes h a v e p l a y e d a n i m p o r t a n t role i n the p r o d u c t i o n of n u c l e a r p o w e r a n d i n the d e v e l o p m e n t of n u c l e a r energy.
The impor-
tance of separated isotopes i n this field c a n be seen at once b y c o n s i d e r i n g the t h e r m a l n e u t r o n cross sections of those isotopes w h i c h h a v e b e c o m e i m p o r t a n t i n the n u c l e a r i n d u s t r y . A f e w of these are g i v e n i n T a b l e I. T h e v e r y s m a l l n e u t r o n a b s o r p t i o n cross section of d e u t e r i u m , c o m p a r e d
Downloaded by 60.199.249.3 on January 17, 2016 | http://pubs.acs.org Publication Date: June 1, 1969 | doi: 10.1021/ba-1969-0089.ch001
with p r o t i u m , together w i t h its excellent m o d e r a t i n g p o w e r , has h e a v y w a t e r a v e r y i m p o r t a n t reactor moderator. Table I.
1 ( )
made
B has f o u n d w i d e -
Thermal Neutron Cross Sections of Some Isotopes Useful for Nuclear Energy Production
Isotope m m
'Natural Abundance (%)
235TJ
99.99 0.015 19 81 99.6 .37 0.7
238TJ
99.3
IOB n
B
14
N
15
N
o- (barns) 0.33 0.0005 4000. 2 3
30 MASS SPECTROMETE BACKGROUND
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29. -»28 20
30
40
510
1 6|0
1
7|0
30 TANK NITROGEN -» 2 9 1 • 1 = » 2 8 x shunt 5
If
1
|
1
1
1 1
Figure 7. Mass spectrometric comparison of N obtained from HN0 enriched by Taylor and Spindel with tank N . "Proceedings of the International Symposium on Isotope Separation" {Kef. 17) North Holland Publishing Co. 2
3
2
COLD
TOWER A
WASTE
SOLUTION
PRODUCT TO N E X T
TRANSFER STAGE
WITHDRAWAL
JHEAT EXCHANGER
2 HEAT
