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Separation of neptunium, plutonium, americium and thorium by anion exchange
NOTES
326 CHROM.
4504
Separation
of neptunium,
plutonium,
americium
and thorium
by anion
exchange
The separation of Np(IV) and Pu(II1) by anion exchange from nitric acidl-3 like U(VI), as well as Pu(IV), U(V1) and Am(III)4 has been reportecl. Because Np(VI), does not form strong anionic complexes, the separation of Np(V1) and Pu(IV) can be carried out by using the agents which hold the neptunium in hexavalent and plutonium in tetravalent state. The difference in the distribution coefficients for Pu(IV) and Th(IV) in nitric acid solutions5-7 gives the possibility for their separation, too. This paper describes investigations carried out on the separation of Np(VI) and Th(IV) from Pu(IV) by anion exchange from nitric acid solution. Americium has also been included in the separation scheme.
SEPARATION OF Am(lII), Np(VI), 'I'h(LV) AND l.'u(lV) Column: 15 cm x 0.11 cm2. Exchanger: rate : 1 rnl/min/cm2. _______-_~.--_.-_-
Elentsnt
No. of samfiles
Pcvccnt
24~AIll
224~rh 222Pu
~---~---
9 9 9 9
100.1
Lb
&
*o.oz LL - _.._.
I.2
I S_F,
Ioo--100
.___. _ __...___ -_ - -
of elements
7.2 M HNO:, (5 5121)
a3’Np
Dowcx
cluted
_.__.__ .._._ _
I.4
HNO,, (25 ml)
.. . ^
_ ._.._
oa35 ilf HNCI,, (IO .WIl)
g 2 f
could not fraction.
1%1w
a
< 0.05 100.3
p”.
-_--_-_-
4.0 iid
u
* The activity of thcsc rnclionucliclcs the neptunium fraction :~ncl 70%, in thorium
.. _
‘I’cmpcraturc:
,i,n fvact~ions
7.2 n/r FILVO:, (IO 1u1)
99.3 f ~O.O.+ < 0.06 - _..._-_--_-.--______
mesh.
bc clctcctecl.
I.3
II
lOO.rl +
0.7 __..---. . _-_ . ..-_..._.-__ _._._... __About
socyi, of ‘J33Pa clutcs
in
Exj+erz’mwta 2 The exchanger Dowex I X4 (100-200 mesh) in Reagmts ad ratliomdidcs. nitrate form was used. The purification and the preparation of the Am and Pu solutions were carried out as described previously4. The isolation of 2”4Th from U0,(N03)2 - OH,0 was done as described earliera. ‘J37Npwas in the form of nitrate in HNO,. The amount of 241Anl ancl 2”4Th used were at the tracer levels. From 4.2 * IO-:~ to 0.45 mg of z37Np ancl I.6 9IO-~ to 1.7 mg of 2%Ju were usecl. All chemicals were of p-a. purity. Detevdnation of mdionuclides. a30Pu, g37Np and z4j.Arn were measured with a Tracerlab Model P-12 alpha scintillation detector. The 234Th was measured with a Nuclear Chicago GM counter. In the presence of the alpha-emitters mentionecl, it is possible to measure 2391 over an absorber of S mg/crnZ altiminium. However, because of the presence of beta-emitters of zs3Pa (which is produced by alpha decay of 237Np), 234Th-234Pa were measured over an absorber of 99.6 mg/cm2 of aluminium. The purity of 23DPu,237Np and 241Arn was checked, i.c. the content of each one in the other two was determined by alpha spectrometric analysis using a Tracerlab, ./.Chl'OttWtO~., 46
(1970)
326-328
- _....__ ._ ~_._..__ -.- _---._.-.-.-.._._ --.--. I ____.,j 5000
t
-
&j
--7.2h’ HN03 ,A
,,p,03
.---.-.....
--.
-.-_--.-. --- -+ -
m3+
.-__--___ 0.35t.f
HII03
2000
**
Th* +
.I500 i
.E 3000-
8
-I
1
lJ*+
4000-
. Y s
-
.E
.
-1000
2000-
I 1000
8
L_ - 500
‘.’
.. .. ‘-kc, 5 0
5 Y s
10
.1 15
A
20
25
I-’ 30
35
# 40
^
zk
1 -I_
50
ml
55
Model RLD-I, I?riscll Grid chamber with a Model 20023 RCL 256 channel pulse height analyser. Clleck of tllc valency state of Np in nitric acid solutions was made spectropl~otoinetricallyf)~10 with a Unicanl SP-500 sI)ectroI?llotometer. in 1-2 Af MNO, were Snllafih prc#Wntio1z. The solution of the radionuclides treated wit11 NH,OH *HCI (0.025--0.05 Af) for 15-30 min and then NatNO, (0.05a.10 AZ) was aclclecl. After 30 min the solution is adjusted to 7.2 A1 HNO:,, thermostated for 30 min at 50” and transferred to tile column, pretreated with a 7.2 M I-INO:, and thernlostated at 50~. Tile amount of sample transferred to the column (15 cn7 x 0.x I cnlz) sllould not exceed I.6 nil,
It was reported that Np(V) in nitric acid higher than 3 111 in the presence of Under the sanle conditions Pu esists as Pu(IV). l’lle NO,- osiclises to Np(VI)ll. anion-eschange behavivur of neptunium in strong nitric acid containing NaNO, was identical to the behaviour of Np(VI) which was prepared by osidising tip with A.@+or Ce4+. Spectrop hotornetric analysis of a neptuniunl solution in 4-7 M HNO:, containing 0.1 hf NaNO, have SIICW~ that Np(V), at 5o”, was osiclisecl to Np(V1). Np(V1) elutes from the anion-csc1~an.q column approsinx~tcly like U(\:I). l‘11e distribution coefficients cleterniinccl by the coluinn nietlioc112 for 7.2 Ail HNO,, at 50” for Np(V1) and U(V1) are 10.4 and 7.0, respectively. On the basis of tliese data as \vell as on tlic basis of tlie data reportecl’~, tile separation of Am(II.I), Np(V1) allcl I’u(I V) was carriccl out (Fig. I). l’lle elution of
NOTES
328
Th(IV) from tllc column has been achieved with 4 A/r HNO,. Results are shown in Table I. As it is seen from Table I satisfactory separation of given radionuclicles is obtained. However, when a sample contained about 0.2 n/r H,SO,, only go’%, of ZS’Njp was recovered. The authors express their thanks to the Yugoslav Federal and Serbian Researcll Funds for financial support. Thanks are also due to Mr. 13. NEI->IXJKOVIC and Mr. B. PRoICIC for their technical assistance in the experiments. D, CVJETI~ANIN S. RATKOVIC
Hot Laljorntovy Dc$artmmt, I3orl:s Kid& Im$itacte of Nacclear Sc~imccs, Vida, Beogvad (Yugoslavia) I 2
3 .{ 5 6 7 Y 9 IO I I 12
L’.. P. 1’. P.
.liOHrtRTS r\ND ‘F. I’. BRAUIER, k@. I-I\V-60552, IC)!j9. ROBERTS, Refit. I-IW-59032, 1959. IL C;. LAGGIS AND C. R. SCHMITT, Rept. Y-1346, rg(ir. 13. CVJETICANIN AN13 S. RATI
I3cwgmd, IO (I gGg) 2 23, Ih.,
GPHPW,
17 (1955) 137. J. P. I;ARIS AN13 13, 1;. 13UCf?ANAN, Rapt. ?-\NL-6811, rrjb.+. J. DARAN, J. Inovg. Nwl. Cireru., 5 (1955) 237. D. CVJ@TI~ANKN AND N. MILIC, 13~111.Rovis Kidvit Iwst. Nvztcl. Sci., I3cqq~~rcrl,15 (rgc5.t) 73. 15. ~IIZSPORD AND I-1.n. c. MCk
MARCUS,
First received J.
sci.,
Pmc~~f~firlUSPS At.
A eta Clrc~rr2.Scnnd.,
II
September ISth,
1969
Chvo~~rato~., 46 (1970)
326-328
(1957)
Grg.
; revised
manuscript received November
zIst,
1gGg
326 CHROM.
4504
Separation
of neptunium,
plutonium,
americium
and thorium
by anion
exchange
The separation of Np(IV) and Pu(II1) by anion exchange from nitric acidl-3 like U(VI), as well as Pu(IV), U(V1) and Am(III)4 has been reportecl. Because Np(VI), does not form strong anionic complexes, the separation of Np(V1) and Pu(IV) can be carried out by using the agents which hold the neptunium in hexavalent and plutonium in tetravalent state. The difference in the distribution coefficients for Pu(IV) and Th(IV) in nitric acid solutions5-7 gives the possibility for their separation, too. This paper describes investigations carried out on the separation of Np(VI) and Th(IV) from Pu(IV) by anion exchange from nitric acid solution. Americium has also been included in the separation scheme.
SEPARATION OF Am(lII), Np(VI), 'I'h(LV) AND l.'u(lV) Column: 15 cm x 0.11 cm2. Exchanger: rate : 1 rnl/min/cm2. _______-_~.--_.-_-
Elentsnt
No. of samfiles
Pcvccnt
24~AIll
224~rh 222Pu
~---~---
9 9 9 9
100.1
Lb
&
*o.oz LL - _.._.
I.2
I S_F,
Ioo--100
.___. _ __...___ -_ - -
of elements
7.2 M HNO:, (5 5121)
a3’Np
Dowcx
cluted
_.__.__ .._._ _
I.4
HNO,, (25 ml)
.. . ^
_ ._.._
oa35 ilf HNCI,, (IO .WIl)
g 2 f
could not fraction.
1%1w
a
< 0.05 100.3
p”.
-_--_-_-
4.0 iid
u
* The activity of thcsc rnclionucliclcs the neptunium fraction :~ncl 70%, in thorium
.. _
‘I’cmpcraturc:
,i,n fvact~ions
7.2 n/r FILVO:, (IO 1u1)
99.3 f ~O.O.+ < 0.06 - _..._-_--_-.--______
mesh.
bc clctcctecl.
I.3
II
lOO.rl +
0.7 __..---. . _-_ . ..-_..._.-__ _._._... __About
socyi, of ‘J33Pa clutcs
in
Exj+erz’mwta 2 The exchanger Dowex I X4 (100-200 mesh) in Reagmts ad ratliomdidcs. nitrate form was used. The purification and the preparation of the Am and Pu solutions were carried out as described previously4. The isolation of 2”4Th from U0,(N03)2 - OH,0 was done as described earliera. ‘J37Npwas in the form of nitrate in HNO,. The amount of 241Anl ancl 2”4Th used were at the tracer levels. From 4.2 * IO-:~ to 0.45 mg of z37Np ancl I.6 9IO-~ to 1.7 mg of 2%Ju were usecl. All chemicals were of p-a. purity. Detevdnation of mdionuclides. a30Pu, g37Np and z4j.Arn were measured with a Tracerlab Model P-12 alpha scintillation detector. The 234Th was measured with a Nuclear Chicago GM counter. In the presence of the alpha-emitters mentionecl, it is possible to measure 2391 over an absorber of S mg/crnZ altiminium. However, because of the presence of beta-emitters of zs3Pa (which is produced by alpha decay of 237Np), 234Th-234Pa were measured over an absorber of 99.6 mg/cm2 of aluminium. The purity of 23DPu,237Np and 241Arn was checked, i.c. the content of each one in the other two was determined by alpha spectrometric analysis using a Tracerlab, ./.Chl'OttWtO~., 46
(1970)
326-328
- _....__ ._ ~_._..__ -.- _---._.-.-.-.._._ --.--. I ____.,j 5000
t
-
&j
--7.2h’ HN03 ,A
,,p,03
.---.-.....
--.
-.-_--.-. --- -+ -
m3+
.-__--___ 0.35t.f
HII03
2000
**
Th* +
.I500 i
.E 3000-
8
-I
1
lJ*+
4000-
. Y s
-
.E
.
-1000
2000-
I 1000
8
L_ - 500
‘.’
.. .. ‘-kc, 5 0
5 Y s
10
.1 15
A
20
25
I-’ 30
35
# 40
^
zk
1 -I_
50
ml
55
Model RLD-I, I?riscll Grid chamber with a Model 20023 RCL 256 channel pulse height analyser. Clleck of tllc valency state of Np in nitric acid solutions was made spectropl~otoinetricallyf)~10 with a Unicanl SP-500 sI)ectroI?llotometer. in 1-2 Af MNO, were Snllafih prc#Wntio1z. The solution of the radionuclides treated wit11 NH,OH *HCI (0.025--0.05 Af) for 15-30 min and then NatNO, (0.05a.10 AZ) was aclclecl. After 30 min the solution is adjusted to 7.2 A1 HNO:,, thermostated for 30 min at 50” and transferred to tile column, pretreated with a 7.2 M I-INO:, and thernlostated at 50~. Tile amount of sample transferred to the column (15 cn7 x 0.x I cnlz) sllould not exceed I.6 nil,
It was reported that Np(V) in nitric acid higher than 3 111 in the presence of Under the sanle conditions Pu esists as Pu(IV). l’lle NO,- osiclises to Np(VI)ll. anion-eschange behavivur of neptunium in strong nitric acid containing NaNO, was identical to the behaviour of Np(VI) which was prepared by osidising tip with A.@+or Ce4+. Spectrop hotornetric analysis of a neptuniunl solution in 4-7 M HNO:, containing 0.1 hf NaNO, have SIICW~ that Np(V), at 5o”, was osiclisecl to Np(V1). Np(V1) elutes from the anion-csc1~an.q column approsinx~tcly like U(\:I). l‘11e distribution coefficients cleterniinccl by the coluinn nietlioc112 for 7.2 Ail HNO,, at 50” for Np(V1) and U(V1) are 10.4 and 7.0, respectively. On the basis of tliese data as \vell as on tlic basis of tlie data reportecl’~, tile separation of Am(II.I), Np(V1) allcl I’u(I V) was carriccl out (Fig. I). l’lle elution of
NOTES
328
Th(IV) from tllc column has been achieved with 4 A/r HNO,. Results are shown in Table I. As it is seen from Table I satisfactory separation of given radionuclicles is obtained. However, when a sample contained about 0.2 n/r H,SO,, only go’%, of ZS’Njp was recovered. The authors express their thanks to the Yugoslav Federal and Serbian Researcll Funds for financial support. Thanks are also due to Mr. 13. NEI->IXJKOVIC and Mr. B. PRoICIC for their technical assistance in the experiments. D, CVJETI~ANIN S. RATKOVIC
Hot Laljorntovy Dc$artmmt, I3orl:s Kid& Im$itacte of Nacclear Sc~imccs, Vida, Beogvad (Yugoslavia) I 2
3 .{ 5 6 7 Y 9 IO I I 12
L’.. P. 1’. P.
.liOHrtRTS r\ND ‘F. I’. BRAUIER, k@. I-I\V-60552, IC)!j9. ROBERTS, Refit. I-IW-59032, 1959. IL C;. LAGGIS AND C. R. SCHMITT, Rept. Y-1346, rg(ir. 13. CVJETICANIN AN13 S. RATI
I3cwgmd, IO (I gGg) 2 23, Ih.,
GPHPW,
17 (1955) 137. J. P. I;ARIS AN13 13, 1;. 13UCf?ANAN, Rapt. ?-\NL-6811, rrjb.+. J. DARAN, J. Inovg. Nwl. Cireru., 5 (1955) 237. D. CVJ@TI~ANKN AND N. MILIC, 13~111.Rovis Kidvit Iwst. Nvztcl. Sci., I3cqq~~rcrl,15 (rgc5.t) 73. 15. ~IIZSPORD AND I-1.n. c. MCk
MARCUS,
First received J.
sci.,
Pmc~~f~firlUSPS At.
A eta Clrc~rr2.Scnnd.,
II
September ISth,
1969
Chvo~~rato~., 46 (1970)
326-328
(1957)
Grg.
; revised
manuscript received November
zIst,
1gGg