rapid actinide analysis for large soil samples-update
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
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