A Simple Method for the Analysis of Po 210 : An Initial Report D.K. Mann and J.K. Franse Y-12 National Security Complex BWXT Y-12 LLC Analytical Services Organization 113C Union Valley Road, Oak Ridge, TN 37830, USA DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make 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. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. COPYRIGHT NOTICE The submitted manuscript has been authored by a subcontractor of the U. S. Government under contract DE‑AC05‑84OR21400. Accordingly, the U. S. Government retains a paid‑up, nonexclusive, irrevocable, worldwide license to publish or reproduce the published form of this contribution, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, or allow others to do so, for U. S. Government
Transcript
A Simple Method for the Analysis of Po210: An Initial Report
D.K. Mann and J.K. FranseY-12 National Security Complex
BWXT Y-12 LLCAnalytical Services Organization
113C Union Valley Road, Oak Ridge, TN 37830, USA
DISCLAIMER
This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make 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. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
COPYRIGHT NOTICE
The submitted manuscript has been authored by a subcontractor of the U. S. Government under contract DE‑AC05‑84OR21400. Accordingly, the U. S. Government retains a paid‑up, nonexclusive, irrevocable, worldwide license to publish or reproduce the published form of this contribution, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, or allow others to do so, for U. S. Government purposes.
General Outline
Little bit of HistoryReview of Pb210 ProcedureProblems with Po210 and Bi210 SeparationDevelopment of Po210 ProcedureData and Final ProcedureBenefits and DrawbacksFuture Work
Introduction
Member of the Uranium Decay Series (found naturally)
Pb210---->Bi210---->Po210
Used extensively as Environmental process tracers (Atmospheric, Terrestrial, Oceanic)
Isotope ratio allows use as source locator
U U-238 U-234 U-232 U-235
4.4680E+0999.84%
2.4450E+05 7.0380E+08
92 y P a234m y 72y y
P a1.17m
P a-231
0.16%
91 P a234 32760y
Th Th-234 6.7h Th-230 Th-232 Th-228 Th-231 Th-227
1.405E+10
90 24.1d 77000y y 1.9132y 25.52h 98.62% 18.718d
Ac Ac-228 Ac-227
89 6.13h 21.773y
Ra Ra-226 Ra-228 Ra-224 Ra2231.38%
88 1600y 5.75y 3.62d 99.994% 11.434d
Fr Fr-223
87 21.8m
Rn Rn-222 Rn-220 Rn-2190.006%
86 3.8235d 55.61s (3%) 3.96s
At At-218 At-219 At-215
85 0.02% (~2s) (0.9m) (0.00023%) (~1E-4s)
P o P o-218 P o-214 P o-210 P o-216 P o-212 P o-215 P o-211
1.637E-04 138.378 2.98E-07 (97%) 0.001778
84 3.05m 99.979% s ~100% d 0.146s 64.07% s s 0.273% 0.516s
Bi Bi-214 Bi-210 Bi212 Bi-215 Bi-211
99.98% 99.99977%
83 19.9m ~100% 5.013d 60.55m (7.4m) 2.13m
P b P b-214 P b-210 P b-206 P b-212 P b-208 P b-211 P b-207
Po210 as source of high alpha in Hi-Vol Ambient Air monitors.
Needed quick and inexpensive method (very little funding).
No funds for Tracer.Minimal Sample Size.Startup time was minimal.
Carrying of Po206 on Te
0.3 M HCL 1.0 HCL 2.0 HCL 3.0 HCL 6.0 HCL
Te 57,470 58,458 57,024 55,866 54,611
Supn’t 570 673 511 930 2,624
Total 58,040 59,131 57,535 56,796 57,235
Te Precipitated by SnCl2
Taken from NAS-NS Nuclear Science Series “The Radiochemistry of Polonium”, pp.56-57, 1961
Dependency of Po210 Recovery on Te Concentration
0
10
20
30
40
50
60
70
0.2mg
0.4mg
0.6mg
0.8mg
1.0mg
Po-210Recovered
Dependence of Resolution on Te concentration
0
20
40
60
80
100
120
140
160
0.2
mg
0.4
mg
0.6
mg
0.8
mg
1.0
mg
Resolution (FWHM)
Dependency of Po210 recovery with varying Acid Concentrations
Plot shows Recovery of Po210 with varying acid concentrations. Average for 0.1M HCL is 66.3 +/- 1.2 with a RSD of 1.8%. When using 4M HCL, the recovery is slightly less, averaging 62.0 +/- 1.3 with a RSD of 2.0 %.
0
20
40
60
80
100
0.6mg
0.8mg
1.0mg
0.1 M HCL4 M HCL
Dependency of Po210 Resolution (FWHM) with varying Acid Concentrations
Plot shows Resolution of Po210 spectrum with varying acid concentrations. Average for 0.1M HCL is 144.7 +/- 13.6 keV with an RSD of 9.4%. When using 4M HCL, the overall resolution is better, averaging 98.8 +/- 19.5 keV with a RSD of 19.5 %. 0
20406080
100120140160180
0.6mg
0.8mg
1.0mg
0.1 M HCL4 M HCL
Recovery of Po209 vs. Po210
Recovery of Po210
averaged 61.2 +/- 2.3% while the recovery of Po209 was slightly higher, at 70.6 +/- 5.1. Excluding 1st point, average drops to 68.2 +/- 1.5
0
10
20
30
40
50
60
70
80
90
Sam #1 Sam #2 Sam #3 Sam #4
% R
ecov
ery
Po-210Po-209
Outline of Po210 Procedure
M ount fi lter on Lexan diskCount sam ple by Alpha Spec
I m m ediately fi lter the ppt through0.1 um M em brane Filter (used of N dF)
W hile still w arm , add 100 u l of0 .5 M SnC l2 . A Black ppt form s
Add 0 .6 m g Te M etal andHeat in Steam bath to 65 -70 Degrees
Convert to 4 M HCL(10-20 m l)
Elute Bi-210 and Po-210 in 10 m l 1 M HN O 3and 0 .1M HN O 3 from EichroM Pb R esin
Benefits of Po210 Method
Relatively InexpensiveRequires no special equipmentAble to use existing Eichrom Pb210
procedureRapid (1 hour from elution to counting)Can use a Tracer
Drawbacks of Po210 Method
Recovery not quantitative (60-70%).Resolution fairly large (70-100 keV).Not as good as PERALS or Silver Disk
method.May not be practical for labs who
Electroplate.
Future Work
Increase recovery (better Flocculation)Decrease FWHM (activity on surface)Try method with High Uranium SamplesWhat is the effect of heatingTry different Filter types (larger/smaller
