Optimizing Radiochemical Methods at SRS Sherrod L. Maxwell, III Westinghouse Savannah River Company

Recent Improvements SRS Environmental Monitoring lab new actinide methods for water, air filters, soil, sediments, sanitary sludge SRS Bioassay lab (with Dave Fauth) increased Pu-Np recoveries faster fecal method (HEDPA-no microwave) F/H Laboratory (Process lab) faster single column separation for Pu/Np in high U samples (U-234 removal of 1E6)

SRS Environmental Monitoring Lab Stacked TEVA + TRU cartridges for all matrices Replaced UTEVA+TRU water samples air filter samples soil, sediments (up to 10 grams) sanitary waste sludge (5 grams) vegetation (10 grams) fruit (100 grams)

Advantages of TEVA+TRU Pu, Np, Am, Cm, U (Th) in a single stacked column Allows Pu and Np together on TEVA (Pu-236 tracer) High retention of Pu, Np on TEVA Higher retention of U on TRU vs. UTEVA Better Po-210 removal (interferes with U-232) and Th removal Removal of TEVA/removal on TRU if any residual

Pu, Np, Am, Cm,U, Sr on TEVA/TRU RESIN (Water/Air filters) 1) Redissolve in 10-15 mL 3M HN03 - 0.5M to 1M Al(NO3)3 2) Add 0.5 mL 1.5M Sulfamic Acid + 1 mL 1.5M Ascorbic Acid 3) Add 1 mL 3 M Sodium Nitrite Th Elution 20mL 9MHCI Rinse 20 mL 3MHN03 Pu, Np Elution 20mL 0.10MHC1 - 0.05MHF - 0.03M TiCl3 Add 0.5 mL 30 wt% H2O2 2mL TEVA Resin (50-100 um) Remove TRU cartridge: 1) Elute Am with 15mL 4M HCI 2) 10 mL 4MHCL-0.2M HF to remove any Th 2) Elute U with 15mL 0.1M ammonium bioxalate Cerium fluoride Alpha spectrometry 2.0mL TRU-Resin (50-100 um) Collect, evaporate, dissolve in 8M HNO3 Sr Resin

Alpha Resolution Improvements Strong HCL can cause extractant bleed-off TEVA: 5 mL 3M HNO3 rinse after 9M HCL Th removal rinse prior to stripping Pu and Np TRU: 4M HCL extractant bleed-off affects resolution (worse with 9M) We have gone back to evaporating 4M HCl with con HNO3 and 100 uL of 1.8M H2SO4, then ash with con HNO3 and H2O2, redissolve in 0.5M HCL 3M HNO3 rinse after 4M HCl-0.2M HF rinse UTEVA/TRU: Using 9M HCl with UTEVA or TRU can affect bleed-off and peak resolution/not needed

Total Dissolution Soil, Sediments, Sludge Actinides in soil, sediment and sanitary sludge samples 5 to 10 gram soil 5 gram sanitary sludge Replaced fusion method which had poor recoveries, load solution problems, and Po-210 problems Total Dissolution sodium peroxide/sodium hydroxide fusion (15-20 minutes) multiple samples fused at once in furnace inexpensive zirconium crucibles

Total Dissolution Soil, Sediments, Sludge, contd. Total Dissolution and matrix removal (1 day) soils: heat at 550C, then nitric acid/HF silicon removal first, then fusion sanitary sludge: heat at 550C, then fusion fusion in zirconium crucibles for 20 minutes at 700C 10 grams sodium peroxide/5 grams sodium hydroxide Hydroxide precipitation with TiCl3 reductant and barium present to eliminate carbonate interference

Total Dissolution Soil, Sediments, Sludge, contd. Redissolve in dilute HCl and perform cerium fluoride precipitation (500 ug to 2 mg Ce) with TiCl3 present Rinse precipitate with 0.25M HCl- 6MHF with 0.02M rongalite present Soil load solution: 5 mLs 3M HNO3-0.25M boric acid, 6 mL 7M HNO3, 7.5 mL 2M AL(NO3)3

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, TiCl3, and barium present

After centrifuging, acidify and add TiCl3, Ce and HF.

Place on ice, then centrifuge

Rinse with dilute HCl, HF with rongalite present

Redissolve in acid, boric acid and aluminum nitrate

Cerium fluoride / Alpha spectrometry Actinides in SOIL 1) Redissolve in 18.5 mL 3M HN03 - 0.8M Al(NO3)3- 0.07M boric acid 2) Add 0.5 mL 1.5M Sulfamic Acid + 1.25 mL 1.5M Ascorbic Acid 3) Add 1 mL 3 M Sodium Nitrite Rinse Beaker rinse: 3mL 5MHN03 Separate cartridges: TEVA: 5 mL 3MHN03 Collect/acidify - with 2 mL16M HN03 then to TRU TEVA:10 mL5M HNO3 8 mL3M HN03 Th Elution 20mL 9MHCI Pu Elution 20mL 0.10MHC1 - 0.05MHF - 0.03M TiCl3 Remove TRU cartridge: 1) Elute Am with 15mL 4M HCI 2) Add 3M HNO3 rinse from TEVA 3) 10 mL 6M HNO3 -remove any Po-210 4) 15 mL 4M HCl-0.2M HF-remove Th 5) Elute U with 15mL 0.1M ammonium bioxalate Add 0.5 mL 30 wt% H2O2 2mL TEVA Resin (50-100 um) Cerium fluoride Alpha spectrometry 2.0mL TRU-Resin (50-100 um) Cerium fluoride / Alpha spectrometry

(warm and rinse original beaker) Am/RE Removal on TEVA 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. Rinse Beaker rinse: 3mL 4M NH4SCN, warm 10 mL 1.5 M NH4SCN to column Am Elution 25 mL 1M HCl (warm and rinse original beaker) 2mL TEVA Resin (50-100 um) Cerium fluoride Alpha spectrometry

Final Am Clean-up on TEVA

QAP 0903-SOIL SRS EML Ratio Pu-238 14.9 14.6 1.021 Pu-239 31.6 30.4 1.039 Am-241 18.3 18.4 0.995 U-234 117.7 127.3 0.925 U-238 119.9 127.1 0.943 Results in Bq/kg 5 gram sample analyzed

Bioassay Lab Improvements Actinides and Sr-90 in urine stacked TEVA+TRU Resin cartridges with vacuum boxes Pu-236 tracer for Pu and Np at same time Pu, Np (TEVA) and U, Am (TRU) Sr (Sr Resin) Pu stripping improvement: Increased rongalite to 0.04M (sodium formaldehyde sulfoxylate) - compatible with electroplating adjust bisulfate added for sulfate added from rongalite decomposition (2.0 mLs 10 % bisulfate instead of 3 mLs)

Bioassay Lab Urine Method Tracer Recoveries 2002 2003 2004 Pu 77.5 86.1 95.1 EU 80.6 83.4 87.4 Sr 82.7 80.1 82.2 Am 83.5 84.3 80.5 Np 76.6 87.1 94.4

Recent Improvements in Fecal Method HEDPA strip of Diphonix instead of microwave destruction (18 mL 0.5M HEDPA) 45 minute hot plate destruction 30 mL of 30 wt% H2O2 Add 200 uL of 1.5M ferrous sulfate 1 mL of concentrated HNO3 Ash to dryness Add 5 mL concentrated HNO3, ash to dryness Add 5 mL 30 wt% H2O2, ash to dryness. Repeat 3 more times. Faster than microwave, but requires more aluminum in load solution due to higher phosphate

Process Lab Improvements Process samples to support HEU Blenddown processing Pu and Np are key product specification measurements Pu-236 tracer for Pu and Np on TEVA resin in HEU and LEU process solutions Improvements: Single cartridge instead of two column method use Ti (III) reductant in Pu strip from TEVA Using 0.5mL 30wt% H2O2 instead of nitrite, much better oxidation of U+4 to U+6 1000 x removal of residual U in cerium fluoride precipitation $100K savings-labor and materials

Summary Future work SRS Environmental Monitoring lab work TEVA+TRU for all matrices Cerium fluoride matrix elimination Bioassay lab Improved Pu stripping using rongalite (95% recoveries) HEDPA to eliminate microwave in fecal analysis (save 1-2 days) Process lab Single cartridge separation for Pu, Np in process lab on high uranium samples (cost/time savings) Future work Ra on MnO2 resin

MnO2 Resin