Low Enriched Uranium Control Applicable to a Range of Potential 99 - PowerPoint PPT Presentation

LA-UR-14-24630 Low Enriched Uranium Control Applicable to a Range of Potential 99 Mo Production Processes I. May 2014 Mo-99 Topical Meeting, June 24-27, Washington D.C . UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 1

NRC Regulations, Title 10 – Nuclear Material Accountancy Requirements  >10,000 g of 235 U containing materials enriched up to 20.00 % is deemed to be special nuclear material of moderate strategic significance. – http://www.nrc.gov/reading-rm/doc- collections/cfr/part074/part074-0041.html  Establish and maintain a measurement control program so that for each inventory period the SEID (Standard Error of Inventory Difference) is less than 0.125 percent of the active inventory – http://www.nrc.gov/reading-rm/doc- collections/cfr/part074/part074-0045.html UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 2

Davis and Gray Titration  Destructive analysis method for quantitative uranium measurement  Titration method used extensively for the analysis of uranium in nuclear materials  M. Bickel, J. Nucl. Mater., 246 (1997), 30-36  W. Davies and W. Gray, Talanta, 11 (1964), 1203 UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 3

Technique for Uranium Analysis - Visible Spectroscopy  Uranyl absorption spectra – can be applied 16 to uranium concentration measurement in 1 M sulfuric acid -1 ) 14 solution -1 cm 12 Molar Absorptivity (L mol 𝐵 = 𝜁𝑑𝑚  – A= absorbance 10 – 𝜁 = molar absorptivity (M -1 cm -1 ) 8 – c= concentration (M) – 6 l= path length, cm 4 l max (peak max, nm) and 𝜁 (molar  absorptivity) vary with chemical composition 2 1 M nitric acid 0 A small aliquot of sample ( e.g. 50  L) and  360 400 440 480 dilute in excess of either 1 M HNO 3 or Wavelength (nm) H 2 SO 4 (2000  L) UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 4

Molar Absorptivity of Uranium(VI) Determined from Matrix of Standard Uranium Solutions  The molar absorptivity Abs 419.5nm = m·[U] + b of uranium(VI) in 1.0 ± 0.4 (y = m·x + b) 0.1 M H 2 SO 4 at 19.5 ± 1.7 Weighted least squares fit results: ° C is 13.736 ± 0.026 cm – 1 m = 13.736 ± 0.026 0.3 Abs 419.5nm b = 0.0001 ± 0.0002 M – 1 at 419.5 nm. 0.2  Accurate molar absorptivity values 0.1 could be obtained for a wide range of chemical 0.0 matrices 0.0000 0.0100 0.0200 0.0300 [Uranium] (M) UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 5

Assay Method Accuracy Testing (151.2 gU/L, 0.6353 mol/L)  The white lines represent 1 0.640 standard deviation of the known molar uranium concentration based 0.638 on gravimetric data from solution 0.636 preparation. 0.634 [U] (M)  The square and circle points are 0.632 the uranium concentrations measured by the spectroscopy 0.630 assay method using 90 or 50 µL 0.628 uranium aliquots, respectively. 0.626  The error bars are the standard deviations in these measurements. 1.0 2.0 3.0  Solution Replicate Number Difference between known and measured values all < 0.7 %. For the 90 µL assays. UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 6

Density Measurements on pH1 Uranium Sulfate Solutions 1.22 U/HSO 4 Solution Density (g/mL) 1.26 U/HSO 4 Solution Density (g/mL) 183.6 gU/L 154.3 gU/L 154.3 gU/L 1.24 1.21 142.5 gU/L 142.5 gU/L 133.4 gU/L 133.4 gU/L 1.22 105.5 gU/L 1.20 1.20 1.19 1.18 1.18 1.16 1.14 1.17 20 40 60 10 20 30 40 50 60 Temperature (°C) Temperature (°C) UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 7

Analysis of Contaminants and Impurities Raman Spectroscopy Detection of Nitrate in 143 gU/L (pH 1) Impact of Cr(III) on the uranium Uranium Sulfate Solution spectroscopy technique 1600 2+ UO 2 143 g/L U sulfate 1400 0.12 % NaNO 3 0.24 % NaNO 3 Raman Intensity 1200 0.52 % NaNO 3 1.37 % NaNO 3 1000 2.79 % NaNO 3 800 600 - NO 3 400 2- 200 SO 4 - ClO 4 - HSO 4 0 1100 1000 900 800 -1 ) Wavenumber (cm UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 8

Chemical Process for the Recovery of Fission Molybdenum-99 • 99 Mo recovery and purification processes • Initial solid target dissolution step undertaken using acid or base (MDS Nordion use a HNO 3 dissolution process) • HEU to LEU conversion: - increase in no. of solid targets, processing runs & waste volume • Most currently operating flow sheets are not well suited to the recycle of uranium • LEU solution target concepts linked to the http://nucleus.iaea.org/HHW/Radio pharmacy/VirRad/Eluting_the_Gen application of titania based sorbents for 99 Mo erator/Generator_Module/Design_p recovery (uranyl nitrate in dilute HNO 3 is a potential rinciples/index.html fuel solution) •Alumina is the ‘Industry Standard’ sorbent UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 9

99 Mo Retention on Alumina – Impact of Uranium Concentration http://www.rertr.anl.go v/Web2002/2003Web /Wilkinson.html. See also D.C. Stepinski et al. in IAEA-TECDOC-1601, 2008 (P73) UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 10

“Inventive Application” of Individual Separation Processes 1. a. Evaporation and addition of HNO 3 b. Target dissolution in HNO 3 . 2. i) Lower soln. temp. and/or evaporate under reduced pressure to crystallize out uranium. ii) Separation of crystalline phase from solution. 3. Preparation of final uranium product, option for recycle/reuse. 4. Remove excess nitric acid and add water to obtain the desired uranium and nitric acid concentration. 5. Recovery of a Mo-99 product using an alumina column. http://en.wikipedia.org/wiki/File:Uranyl_nitrate.jpg UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 11

Experimental Validation UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 12

Crystallization Process Removes Most of the Uranium Solution Solution LEU Mo-99 Crystals Crystals UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 13

Crystallization Provides a Purified Uranium Nitrate ‘Product’ UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 14

Alumina Column Separation Recovers the 99 Mo 14 12 Feed solution contained 10 'low' uranium concentration pH 8 6 4 100 2 Activity(µCi/ml) 0 10 Mo-99 Example fission product 1 0.1 0.01 1 2 3 4 5 6 7 8 9 10 Column Fraction UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 15

Acknowledgements Analysis of Uranium Uranium Crystallization Process   D. Rios & S. D. Reilly (LANL) A.S. Anderson, R. Copping, G.E, Dale, D.A. Dalmas, M.J.  J. Driscoll (SHINE Medical Gallegos, L.A. Hudston, C.T. Technologies) Kelsey IV, M. Mocko, S.D.  The NNSA Global Threat Reilly, D. Rios, F.P. Romero Reduction Initiative (GTRI) and K.A. Woloshun  LANL Laboratory Directed Research & Development – Exploratory Research project UNCLASSIFIED Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA UNCLASSIFIED | 16