Technical Updates on TRU and TEVA Resins

Anil Thakkar, E. Philip Horwitz, Laurie Wojtko, Lawrence Jassin & Michael Fern

November 5, 2001

Topics

• TEVA Resin: Extractant (nitrate) vs TEVA Extractant (chloride)

• TRU Resin: Am Yields

• TEVA Resin: Decontamination of U-nat/Th in Tc-99 region

TEVA Resin: Cl vs NO3

• Uptake of Th, Np and Pu– Preconditioned with 3M HNO3

– Not conditioned

• Uptake of Tc-99

TEVA Resin

• Nitrate form TEVA- Prepacked columns TE1A

• Chloride form TEVA- Bulk lot # TEA0515

Th & Np procedure (ACW08)

1) Spike 10 ml of 3M HNO3/1M Al(NO3)3 with

Th-229 and Np-237. Add ferrous sulfamate

2) Load solution on TEVA Resin columns

3) Rinse with 35 ml of 2.5M HNO3/0.1 M ferrous sulfamate

4) Rinse with 5 ml of 2.5M HNO3

ACW08...Continued

5) Strip Th with 20 ml of 9M HCl + 5 mL 6M HCl

6) Strip Np with 10 ml of 0.02M HNO3/0.02M HF

TEVA Resin: Th-229 recoveries (n=4)

Resin Type Pre-conditioned NotPre-conditioned

Chloride 95.8% + 5% 93.2% + 9%

Nitrate 92.8% + 11% 93.2 % + 6%

TEVA Resin: Np-237 recoveries (n=4)

Resin Type Pre-conditioned Not Pre-conditioned

Chloride 93.8% + 4% 105% + 4%

Nitrate 91% + 6% 103 % + 5%

TEVA Resin: Pu Uptake

1) Spike 10 ml of 3M HNO3 with Pu-242.

2) Load solution on TEVA resin columns

3) Rinse with 10 ml of 3M HNO3

4) Strip with 20 ml of 0.05M HCl / 0.02M TiCl3 / 0.05M HF solution

TEVA Resin: Pu recoveries

Resin Type Preconditioned Not Preconditioned

Chloride 91.7% + 2% (n=4)

93% + 5% (n=5)

Nitrate 90.8% + 2% (n=5)

94.8% + 4% (n=5)

TEVA Resin Column: Tc-99

1) Precondition columns with 5 mL of 0.01M HNO3

2) Spike 50 mL of 0.01M HNO3 with Tc-99

3) Load on TEVA columns

4) Rinse with 25 mL of 0.01M HNO3

5) Cut column and extrude resin into a LSC vial

6) Add 15 mL of ultima gold cocktail

7) Count on LSC

TEVA Resin Column: Tc-99 (n=6)

Resin Type Recoveries

Chloride 103% + 1%

Nitrate 87.5% + 6

TEVA Resin: Conclusion

• Two forms: chloride and nitrate performed well for Th, Np, Pu & Tc uptake

• Preconditioning versus not preconditioning doesn’t seem to affect the uptake of Th, Np or Pu

• Tc-99 recoveries for chloride form are little higher than the nitrate form

TRU Resin: History

• Historical problems with Am recoveries from TRU Resin (HCl strip.)

• Suspected Extractant Leaching handled with wet ashing of HCl Strip Solution

TRU Resin Cartridges

1) TRU Resin

2) TRU Resin with a ‘post’ Prefilter layer

Am-243 Spike Test

1) Spike 10 ml of 3M HNO3 with 6.52 dpm of Am-243

2) Load solution on TRU cartridges (assisted with VBS, flow rate 1ml/min)

3) Rinse with 10 ml 3M HNO3

4) Rinse with 5ml of 0.5M HNO3

5) Strip Am with 9M + 4M HCl

Cerium Fluoride Precipitation

Four different preparation prior to CeF3 ppt.

– 1) Digested with Aqua-regia

– 2) Undigested

– 3) Changed molarity (~0.5 M HCl)

– 4) Digested with 10% H2SO4

Am-243 recoveries (n=4)

Resin Type Am StripSolution

Digestedwith Aqua-

regia

No digestion Changedmolarity

Digested withH2SO4

TRU 9M HCl +4M HCl

89 % + 3% 48 % + 3% 97 % + 7% 84 % + 6%

TRU withprefilter layer

9M HCl +4M HCl

89 % + 5% 62 % + 5% 97 % + 3% 82 % + 23%

RETEST: Am-243 recoveries (n=4)

Resin Type Am StripSolution

Changedmolarity-First Run

Changedmolarity-RERUN

TRU 9M HCl +4M HCl

97 % + 7% 93 % + 10%

TRU withprefilter layer

9M HCl +4M HCl

97 % + 3% 95 % + 4%

ACW03 tested for Am

• 0.5 L of Eichrom tap water spiked with Am-243• Precipitated Am with calcium phosphate• Scavenge ppt. and dissolve in the load solution• Followed ACW03 procedure using UTEVA/TRU

cartridges• Collect Am fraction

ACW03…continued

6) Evaporate Am fraction to dryness

7) Add 0.5 ml of conc. HCl and dilute to 15 DI water

8) Perform CeF3 ppt.

Tap Water: Am-243 recoveries(n=5)

Resin Type Am StripSolution

Changedmolarity

UTEVA / TRU 9M HCl +4M HCl

89 % + 10%

UTEVA / TRU withprefilter layer

9M HCl +4M HCl

89 % + 11%

Conclusion

• Am recoveries improved by changing the concentration on HCl prior to CeF3

• TRU resin cartridge performed well once the HCl concentration was changed

TEVA Column: Tc-99 Issues

• Problem reported by Darrin Mann (BWXT, Oak Ridge, Tn) with bias high Tc-99 recoveries in samples with natural uranium.

• Th-234 interference was detected in Tc-99 region.

BWXT’s Tc-99 Procedure

• Solid samples are digested and dissolved finally in 20 ml of 0.1M HNO3

• Load sample on TEVA column• Rinse column with 25 ml of 0.1M HNO3• Extrude resin from the column in a LSC vial.• Add cocktail and count on LSC.

BWXT’s Procedure tested at Eichrom

• Spiked 20 ml of 0.01HNO3 with ~2000 dpm of

U-234/238• Load on TEVA Resin column• Rinse with 25 ml of 0.1M HNO3• Extrude resin in LSC vial• Added 15 ml of cocktail and count

Possible Solutions for Decontamination

• Use of fluoride to complex the residual Th-234 on the column

• Two fluoride solutions tested:– Hydrofluoric acid

– Sodium fluoride

Decontamination of Th-234• Spiked 20 ml of 0.01HNO3 with ~2000 dpm of

U-234/238• Load on TEVA Resin column• Rinse with 5 ml of 0.1M HNO3• Rinse with 25 ml of 0.5M HF/0.02M HNO3 OR

with 25 ml of 1M NaF/0.02 HNO3• Rinse with 5 ml of 0.1 HNO3• Extrude resin in LSC vial• Added 15 ml of cocktail and count

BWXT’s ProcedureTest Results

TEVA Lot#

25 0.1MHNO3 rinse

25 ml 0.5MHF/0.02M

HNO3

25 ml 1MNaF/0.02M

HNO3TEA06309 72 cpm

(n=2)14.84 cpm

(n=3)Not tested

TE0K 18.9 cpm(n=3)

13.1 cpm (n=2) 15.36 cpm(n=2)

TEVA cl-

form24.5 cpm

(n=2)15.36 cpm

(n=2)15.0 cpm (n=2)

Blank 14.7 + 0.9cpm

14.7 + 0.9 cpm 14.7 + 0.9 cpm

Conclusion

• Decontamination of Th-234 in Tc-99 region can be accomplished with additional fluoride rinse on the TEVA Resin columns

• Fluoride in the form of 1M NaF or 0.5M HF solutions could be used to remove the residual amounts of Th-234