Rapid Determination of Actinides
in 1g Concrete and Brick Samples

AN-1432
Summary of Method U, Pu, Np, Am and Cm are separated and concentrated from 1 gram samples of concreteand brick. Samples are fused with NaOH at 600°C in zirconium crucibles. The fusion cakes are dissolved in water,transferred to 250mL centrifuge tubes and precipitated sequentially with iron-hydrous titanium oxide and lanthanum
fluoride to facilitate matrix removal. Actinides are separated on stacked 2mL cartridges of Eichrom TEVA, TRU and DGA
resins. Actinides are measured by alpha spectrometry following CeF3 microprecipitation onto Eichrom Resolve® Filters.
Chemical yields of tracers ranged from 79-98% for 236Pu, 77-90% for 243Am, and 72-81% for 232U. Measured values
typically agreed to within 10% of reference values. Sample preparation for batches of 12 samples can be completed by asingle operator in <8 hours. Alpha spectrometry count times will depend on detection limit and data quality objectives.
Reagents
TEVA Resin, 2mL Cartridges (Eichrom TE-R50-S)
TRU Resin, 2mL Cartridges (Eichrom TR-R50-S)DGA Resin, 2mL Cartridges (Eichrom DN-R50-S)
Iron carrier (50mg/mL Fe, as ferric iron nitrate)
242Pu (or 236Pu if meas. Np), 243Am and 232U tracers
Oxalic acid/Ammonium oxalate
La carrier (10mg/mL) Ce carrier (1mg/mL)
Deionized Water
1.25M Ca(NO3)2
3.2M (NH4)2HPO4
2M Al(NO3)3
10% (w:w) TiCl3
HNO3 (70%)
HCl (37%)
NaOH
HF (49%) or NaF
Boric acid
H2O2 (30%)
NaNO2Denatured ethanol
Sulfamic Acid
Ascorbic Acid
Equipment
Vacuum Box (Eichrom AR-24-BOX or AR-12-BOX)
Cartridge Reservoir, 20mL (Eichrom AR-200-RV20)
Inner Support Tubes-PE (Eichrom AR-1000-TUBE-PE)
Yellow Outer Tips (Eichrom AR-1000-OT)
Resolve Filters in Funnel (Eichrom RF-DF25-25PP01)
50mL and 250mL Centrifuge Tubes
Centrifuge
Heat Lamp
Muffle Furnace
Hot Plate
Analytical Balance
250mL Zirconium crucibles with zirconium lids
Stainless Steel Planchets with adhesive tape
Alpha Spectrometry System
Vacuum Pump

Figure 1. Sample Preparation
1g milled Concrete or Brick + tracers in zirconium crucible.
Fuse samples with 15g NaOH at 600°C for 15 minutes.
Dissolve fusion cake with H2O. Transfer to 250mL c-tube.
Add 10mL 3M HNO3 to crucible. Heat to dissolve residue.
Transfer to same 25mL c-tube.
Add 125mg Fe and 5mg La to c-tube. Dilute to 180mL.
Add 2mL 1.25M Ca(NO3)2, 3mL 3.2M (NH4)2HPO4,5mL 10% TiCl3. Mix. Cool in ice bath for 10 min.
Centrifuge at 3500rpm. Decant Supernate.
Partially dissolve precipitate in 60mL 1.5M HCl.
Some solids will remain. Dilute to 170mL.
Add 1mg La, and 3mL 10% TiCl3. Mix.
Add 20mL 49% HF. Cool in ice bath for 10 min.
Centrifuge at 3500rpm. Decant Supernate.
Dissolve precipitate in 5mL 3M HNO3-0.25M Boricacid, 7mL 70% HNO3, and 7mL 2M Al(NO3)3.
Warming samples can help complete dissolution.
Cool samples to room temperature.
Fix valence states. Mix between each addition of: 0.5mL
1.5M sulfamic acid, 10uL 50mg/mL Fe, 1.5mL 1M
ascorbic acid, 1mL 3.5M NaNO2, 1.5mL 70% HNO3.

Figure 2. Actinide Separation on TEVA - TRU - DGA* and Source Preparation(1) Precondition stacked 2mLTEVA, TRU, DGA cartridges
TEVAwith 10mL 3M HNO3.
(2) Load sample solution.
(3) Rinse sample tube
with 5mL 3M HNO3.* AddTRUtube rinse to cartridges.
(4) Rinse cartridges with
10mL 3M HNO3.
DGA(5) Separate TEVA, TRU,and DGA cartridges.
(6) Rinse TEVA cartridge with:-10mL 3M HNO3
-20mL 9M HCl-5mL 3M HNO3
(7) Strip Pu (and Np) from TEVA
cartridge with 20mL 0.1M HCl0.05MHF-0.01M TiCl3 .
(8) Add 0.5mL 30% H2O2 for Uranium
decon. in alpha source preparation.
(9) Rinse DGA cartridge with 10mL
0.1M HNO3.
(10) Place TRU cartridge above DGA.
(11) Strip Am/Cm from TRU onto
DGA with 15mL 4M HCl .

(12) Separate TRU cartridge from DGA (23) Rinse sample tube with 5mL DI
water and add to filter.
cartridge. Set TRU aside for U recovery.
(13) Rinse DGA cartridge sequentially(24) Rinse filter
with: -5mL 4M HClfunnel with 3mL-5mL 1M HNO3
DI water and 2mL-15mL 0.05M HNO3
100% ethanol.
(14) Strip Am and Cm from DGA with(25) Draw vacuum
10mL 0.25M HCl. Add 0.2mL 30% H2O2.
until filter is dry.
(15) Rinse TRU cartridge with 15mL
4M HCl-0.2M HF-0.002M TiCl3 .

(26) Remove filter fromfunnel assembly andmount filter on stainlesssteel planchet with 2-sided tape.

(16) Rinse TRU cartridge with 10mL
8M HNO3 .
(17) Strip U from TRU with 15mL of
0.1M ammonium bioxalate.
(18) Add 0.5mL 10% TiCl3.
(19) Add 50ug Ce carrier to all samples.
Mix well. Add 1mL 49% HF. Mix well.
Wait 15-20 minutes.
(20) Set up Resolve® Filter Funnel onvacuum box.
(21) Wet filter with 3mL 80% ethanol
followed by 3mL DI water.
(22) Filter sample.

(27) Dry filter under heat lamp for
3-5 minutes.
(28) Measure actinides by alpha
spectrometry.

*Adding 50uL 30% H2O2 to the tube rinse can improve Uranium recoveries and decontamination in the Pu/Np fraction.

Analyte
239

Pu

238

Pu

237

Np241

Am

244

Cm238

U

234

U

Replicates
5Method Performance
AnalyteTracer
ReferenceTracer% Yield(mBq/g)
236
90 + 718.0
PuAnalyte
Measured(mBq/g)
18 + 2% Bias
0.05236

90 + 7

14.8

15 + 2

1.4

5236

Pu

90 + 737.0

33 + 1-115243

Am

85 + 625.4

24 + 1-5.5

5243

85 + 635.0

35 + 2

0.0

5

232

77 + 329.6

31 + 3

4.7

5

232

77 + 328.4

26 + 4-8.5

Pu

AmUU

References1) Sherrod L. Maxwell, Brian K. Culligan, Angel Kelsey-Wall, Patrick J. Shaw, “Rapid radiochemical method for determination of actinides in emergency concrete and brick samples,” Analytica Chimica Acta, 701(1), 112-118 (2011).
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