Rapid Determination of Pu/Npand Am/Cm in Granite$1--
6XPPDU\ RI 0HWKRG Pu/Np and Am/Cm are separated and measured from 1 gram samples of granite. Samples
are finely ground and fused in a zirconium crucible for 15 minutes at 600°C with 15 grams of NaOH. The fusion cake isdissolved in water, and actinides are concentrated and separated from the matrix using a calcium phosphate precipitate
enhanced with iron. A secondary precipitation with calcium fluoride removes additional matrix (including silicates) anddecreases the volume of precipitate. The calcium fluoride precipitate is dissolved with nitric acid-boric acid-aluminum
nitrate to form the load solution. Analytes are separated from remaining matrix and potentially interfering radionuclides
using stacked 2 mL TEVA and DGA Resin cartridges. Actinides are measured by alpha spectrometry after CeF3
microprecipitation onto Resolve(R) Filters. An additional separation of Am/Cm from rare earth elements using TEVA
resin and ammonium thiocyanate may be required for samples with significant rare earth content. The rugged samplepreparation technique enables high tracer recovery and excellent analytical results, even when refractory materials arepresent.
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5HDJHQWVTEVA Resin, 2 mL Cartridges (Eichrom TE-R50-S)
1 g finely ground sample in zirconium crucible
Add 242Pu or 236Pu and 243Am tracers.
DGA Resin, 2 mL Cartridges (Eichrom DN-R50-S)
Lanthanum and Cerium Carriers (10 mg/mL)
Heat samples to dryness on hot plate.
Iron Carrier (50 mg/mL Fe, as ferric nitrate)
242Pu (or 236Pu if Np is measured) tracer
Add 15 g of NaOH.
243Am tracer
10-20% TiCl3
Cover crucibles with zirconium lids.
Ammonium Thyiocyanate
HF(49%)
Fuse at 600°C for 15-20 minutes.
30% H2O2
Nitric Acid (70%)
Hydrochloric Acid (37%)
Deionized Water
Carefully remove samples from furnace and1.25M Ca(NO3)2
3.2M (NH4)2HPO4cool in fume hood. Add 25-50 mL of water and2M Al(NO3)3
Boric Acid
heat on hot plate to dissolve fusion cake.
Sodium Hydroxide
Ascorbic Acid
Transfer to a 250 mL centrifuge tube. Rinse
NaNO2crucible with water. Dilute to 180 mL with water.
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Vacuum Box (Eichrom AR-24-BOX or AR-12-BOX)
Cool to room temperature. Add 125 mg Fe, 4 mg La, andCartridge Reservoir, 20 mL (Eichrom AR-200-RV20)
50 mg Ca. Mix. Add 5 mL 3.2M (NH4)2HPO4 . Mix. Add 4 mL
Inner Support Tubes-PE (Eichrom AR-1000-TUBE-PE)
20% TiCl3. Mix. Centrifuge 10 min. Decant supernate.
Yellow Outer Tips (Eichrom AR-1000-OT)
Resolve Filters in Funnel (Eichrom RF-DF25-25PP01)
Dissolve precipitate in 80 mL 1.5M HCl. Dilute to 170 mL.
50 mL and 250 mL Centrifuge Tubes
Add 2 mL 20% TiCl3, 25 mg Ca, and 20 mL 49% HF. Mix.
250 mL Zirconium crucibles with zirconium lids
Cool in ice bath 10 min. Centrifuge 10min. Decant supernate.
Alpha Spectrometry System
Stainless Steel planchets with two sided tape
Dissolve precipitate in 7 mL 3M HNO3-0.25M H3BO3,Centrifuge
6 mL 7M HNO3, and 7 mL 2M Al(NO3)3.
Muffle Furnace
Adjust valence with 1 mg Fe, 1.25 mL 1M ascorbic
Hot Plate/Heat Lampacid. Mix. Wait 5-10 min. Add 1 mL 3.5M NaNO2 andAnalytical Balance
1.5 mL 70% HNO3.
Vacuum Pump)LJXUH$FWLQLGH6HSDUDWLRQRQ7(9$-'*$DQG6RXUFH3UHSDUDWLRQ(1) Precondition stacked 2 mL
TEVA and DGA cartridges
with 10 mL 3M HNO3.
(2) Load sample solution.
(3) Rinse sample tube
with 5 mL 6M HNO3. Addtube rinse to cartridges.*(4) Rinse cartridges with
10 mL 3M HNO3.
(5) Separate TEVA and DGA
cartridges.

Optional Am/Cm rare earth separation.

TEVA

DGA

(10) Add 2 mL 70% HNO3 + 50 uL 10%
H2SO4 to Am/Cm. Evaporate to dryness. (23) Rinse sample
tube with 5 mL DI(11) Ash to dryness with 3 mL 70%
water. Add to filter.
HNO3 + 2 mL 30% H2O2.
(24) Rinse funnel(12) Dissolve Am/Cm in 5 mL
with 3 mL DI water
4M NH4SCN-0.1M Formic acid.
(13) Precondition 2 mL TEVA with 5 mL and 2 mL 100ethanol.
4M NH4SCN-0.1M Formic acid.
(14) Load Am/Cm on TEVA.
(15) Rinse Am/Cm beaker with 5 mL
4M NH4SCN-0.1M Formic acid.
Add to TEVA.
(16) Rinse TEVA w/ 10 mL 1.5M
NH4SCN-0.1M Formic acid.
(17) Strip Am/Cm from TEVA with
20 mL 1M HCl.

(6) Rinse TEVA cartridge with:-15 mL 3M HNO3 (U decon.)-20 mL 9M HCl (Th)
-5 mL 3M HNO3
(7) Strip Pu (and Np) from TEVA
cartridge with 20 mL 0.1M HCl0.05MHF-0.01M TiCl3.

(22) Filter sample.

(25) Draw vacuum
until filter is dry.
(26) Remove filter from funnel.
Mount filter on stainless steel
planchet with 2-sided tape.

(18) Add 0.5 mL 30% H2O2 to Pu, and(8) Rinse DGA cartridge with:
0.2 mL 30% H2O2 to Am/Cm samples.
-10 mL 3M HCl(19) Add 50ug Ce to Pu and Am/Cm-3 mL 1M HNO3samples. Mix well. Add 1 mL 49% HF.
-20 mL 0.1M HNO3 (U decon.)Mix well. Wait 15-20 minutes.
-10 mL 0.05M HNO3®
(27) Dry filter under heat lamp for-20 mL 3M HNO3-0.25M HF (Th) (20) Set up Resolve Filter Funnel onvacuum box.
3-5 minutes.
-5 mL 4M HCl(28) Measure actinides by alpha(9) Strip Am and Cm from DGA with (21) Wet filter with 3 mL 80% ethanol
followed by 3 mL DI water.
spectrometry.
10 mL 0.25M HCl.
*Adding 50uL 30% H2O2 to the tube rinse can improve Uranium recoveries and decontamination in Pu(Np) fractions.
Method Performance for 1 gram Granite Samples

239

Pu

Samplereplicates
8239

Pu

621.2

20.1 + 1.2

5.4

97.2 + 5.8

238

Pu

625.2

25.0 + 2.2

6.9

97.2 + 5.8

Np

637.0

37.1 + 1.7

3.5

97.2 + 5.8

Am4

37.0

37.7 + 3.3

7.0

90.7 + 5.1

Cm433.1

34.4 + 2.0

5.2

90.7 + 5.1

Analyte237241244

Reference(mBq/g)
29.4

Measured(mBq/g)29.2 + 1.4

Average% Diff.
4.3

Tracer% Yield
92.1 + 5.5

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1) Maxwell, S.L. Culligan, B. Hutchinson, J.B. Sudowe, R. McAlister, D.R. “Rapid Method to Determine Pu, Np, Am/Cmin Granite Samples,” J. Radioanal. Nucl. Chem. 140, 102-108 (2018).
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