Rapid Actinide Analysis for Large Soil Samples-Update

Sherrod L. Maxwell, III

Westinghouse Savannah River Company

SRS Soil Method

• Total Dissolution

• High recoveries

• Faster Sample preparation

• Good alpha resolution

• Effective removal of interferences such as Th isotopes and Po-210

Update-Improvements

• Enhancements to improve precipitation steps

• Better Am recovery for difficult samples– DGA Resin added to column method

Transfer to crucible after silicon removal

10 grams sodium peroxide + 5 grams sodium hydroxide

700C for 20 minutes

Just add water after cooling briefly

Dilute to 1 liter with water with iron carrier (increased to 150-250 mg), TiCl3, and barium (1.5 mL of 10%) present, add 5-10 mg Ce

After centrifuging, acidify and add TiCl3, Ce (2mg) and HF.

Place on ice, then centrifuge

Rinse with 0.25M HCL-3.8M HF-0.04M rongalite

Redissolve in acid, boric acid and aluminum nitrate

Actinides in Soil

RinseBeaker rinse: 3mL 6MHN03

Separate cartridges:TEVA: 5 mL 3MHN03 Collect/acidify - with 2 mL16M HN03 then to TRUTEVA:10 mL 5M HNO3 Discard

10 mL 3M HN03 Discard

Th Elution20mL 9MHCI

Pu (and/or Np) Elution20mL

0.10MHC1 - 0.05MHF - 0.03M TiCl3

1) Redissolve in 5 mL warm 3M HN03 - 0.25M boric acid, add 6mL 7M HNO3 and 7.5 mL 2M Al(N03 ) 3

2) Add 0.5 mL 1.5M Sulfamic Acid + 1.25 mL 1.5M Ascorbic Acid3) Add 1 mL 3.5 M Sodium Nitrite

2 mL TEVA Resin(50-100 um)

2 mL TRU-Resin (50-100 um)

Alpha spectrometry

Cerium fluoride

Add 0.5 mL 30 wt% H2O2

2 mL DGA-Resin (50-100 um)

Actinides in Soil with DGA

Remove TRU and DGA cartridge:

1) Rinse TRU+ DGA with 3 mL of 3M HNO3 and discard rinse.

2) Elute any U from DGA only with 6 mL of 0.25M HNO3 (then add 5 mL con. HNO3 to adjust acid)

3) Elute Am from DGA only with 10 mL 0.1M HCl. Add 4 mL of con. HCl to soln. To adjust acid to 3.5 M HCl.

4) Add DGA strip solution (con HCL added) to TRU to strip Am from TRU, recombine Am. Rinse TRU with 3M HCl.

Actinides in Soil with DGA, Cont.

5) Add 3M HNO3 rinse (then adj. ~7M HNO3) from TEVA to load to TRU

6) Add U fraction from DGA adjusted to ~ 7M HNO3 to add any U from DGA to TRU and remove any Po-210.

7) Add 18 mL 4M HCl-0.2M HF to TRU to remove Th

8) Elute U with 15mL 0.1M ammonium bioxalate

Load with TEVA+TRU+DGA

Split Apart TEVA and TRU/DGA

Rinse, then strip Pu from TEVA

Strip Am/Cm fromDGA/add acid/thenpass thru TRU

Am/RE Removal on TEVA

Rinse

Beaker rinse: 3mL 4M NH4SCN, warm

10 mL 1.5 M NH4SCN to column

Am Elution25 mL 1M HCl

(warm and rinse original beaker)

1) Evaporate 4M HCl with 5mL con.HNO3, 50 uL of 1.8M H2SO4, then ash with nitric acid and hydrogen peroxide

2) Redissolve in 5 mL of 4M NH4SCN, warm gently.

2mL TEVA Resin(50-100 um)

Alpha spectrometry

Cerium fluoride

Final Am Clean-up on TEVA

10 g sample

5 g sample-Resolve Filters

5 g sample-Resolve Filters

MAPEP samplewith DGA

MAPEP samplewith DGA

MAPEP samplewith DGA

Summary

• Enhanced precipitation steps– Cerium added during iron hydroxide ppt.

• Increased for sandy samples

– Increased barium during iron hydroxide ppt.– lower HF/increased rongalite in final rinse of

cerium fluoride ppt.

• Improved Am recoveries– DGA resin