Offgas from Radiolysis Difficult analysis needing High Resolution Mass Spectrometry

Transcription

1 Offgas from Radiolysis Difficult analysis needing High Resolution Mass Spectrometry William A. Spencer, Charles L. Crawford, Thomas L. White, Stephen L. Crump, Robert J. Lascola, Chris Beam, and Laura L. Tovo, WSRC-MS Operated for Department of Energy by Westinghouse Savannah River Company, Aiken, SC

2 Basic Radiolysis High doses of radiation [gamma and alpha] can generate reactive and flammable gas mixtures. The gases limit plant processes because of the requirements to meet the lower flammability limits [LFL/LEL]. The analytical chemist must determine the rates of gas generation and often determine the LFL. Interaction with Water production of hydrogen Interaction with Air H 2 O e -, H, H 2, OH, H 2 O 2, HO 2,H + Air (N 2 +O 2 ) NO, NO 2, N 2 O 4, N 2 O Air + water vapor, H 2 NH 3, NH 4 OH, NH 4 + Interaction with Organic compounds [good online ref [Radiochemistry in Nuclear Power Reactors (166), National Academy of Sciences] Tributylphosphate [extractant for U/Pu] TBP DBP + t- butanol DBP MBP + t-butanol Butanol isobutane, isopentanol, butanal, methane, ethylene, hydrogen, peroxides Tetraphenylborate (extractant for Cs) TPB phenols, benzene, hydrogen, methane, cyclohexenes, cyclohexanol, phenylates, PAHs WSRC-MS Slide 2

3 Gamma Radiolysis Studies Radiation Cobalt 6* Chamber 6 x8 or 1O cube Sample Size - up to liter Exposures minutes to weeks Rad dose is adjustable 1 R/hr to 2 E6 R/hr distance from source Web srtc/srtchtm/gamma.htm * note yellow light is fake WSRC-MS Slide 3

4 Gamma Radiolysis Studies Material/Offgas analyzed Pressure Measured real-time Temperature Watched real-time Mass Scan in-situ GC Scan in-situ Microscopy Hardness/Tensile Testing DMA/TMA/IR/TGA WSRC-MS Slide 4

5 Most Measurements are made with GC or Quadrupoles Mass Spectrometers Low Resolution Quadrupole Scans During a Radiolysis Experiment Detector Mas s (in tenths of amu) Tim e WSRC-MS Slide 5

6 2.E-6 1.8E-6 1.6E-6 1.4E-6 1.2E-6 1.E-6 8.E-7 6.E-7 4.E-7 2.E-7.E+ -2.E-7 Most Measurements are made with GC or Quadrupoles Mass Spectrometers Hydrogen Water Nitrogen Oxygen Argon 8/28/2 15:23 8/2/2 15:11 8/3/2 15:2 /6/2 14:54 8/2/2 15:21 8/3/2 15:7 8/31/2 15:16 /6/2 14:43 8/3/2 15:18 8/31/2 15:28 /1/2 15:27 /6/2 14:33 8/31/2 15:43 /1/2 15:11 /2/2 15:2 /6/2 14:22 /1/2 15:41 /2/2 15:5 /3/2 15:27 /6/2 14:1 /2/2 15:34 /3/2 15:1 /4/2 15:43 /6/2 13:57 /3/2 15:44 /4/2 15:28 /5/2 16:17 /6/2 13:46 /4/2 15:56 /5/2 16:4 /6/2 13:1 /5/2 16:32 /6/2 13:6 /6/2 13:32 R1R1R1 R1 R2R2R2 R2 R3R3R3 R3 R4R4R4 R4 R5R5R5 R5 R6R6R6 R6 R7R7R7 R7 R8R8 R8 R R R1A WSRC-MS Slide 6

7 Common Mass Problem Is it CH4 or O, CO or N2, CO2 or N2O? Species M/z Possible Source O 15.4 oxygen NH ammonia fragment CH methane OH hydroxide -water fragment, alcohols NH ammonia H2O 18.1 water NH ammonium ion Ar argon Ne 1.24 neon D2O 2.22 heavy water Si from silanization or Si oxides, [sand is in all our samples from airborne dust - we work on top of sand hills inside concrete structures] CO 27.4 carbon monoxide N nitrogen C2H ethylene N2H protonated nitrogen - [common in traps] C2H5 2.3 ethane organic fragment NO 2.7 nitrogen monoxide C2H ethane CH2O aldehyde or alcohol fragment Ar argon C3H4 propane fragment CO carbon dioxide N nitrous oxide C2H4O acetal aldehyde or ethanol fragment [ we see from HEDTA extractants] C3H Propane WSRC-MS Slide 7

8 Siemens Quantra FTICR Extremely High Resolution - >3K at M28 Ion Trap Limits on mixtures Ion interactions Ion Pump no Turbo Pico-liter injection valve Flow Across inlet Mass Range 6-1 WSRC-MS Slide 8

9 JEOL GCMATE II GC/MS Resolution >5 Mass Spectral Library Mass Range 1-1 Dual Pumping Multi-Sector Magnetic Electron Source Tunable Plates Easy Acceleration Adjustments Adjustable Beam Focus Electrostatic or Magnet Sweep Low (<2) vs High Mass (>2) Separate tuning WSRC-MS Slide

10 High Resolution Siemens Quantra Spectra note: Chemical Ionization of H2 and N2 forming N2H at mass 2 WSRC-MS Slide 1

11 Mass 28 Carbon Monoxide, Nitrogen Gas, Ethylene WSRC-MS Slide 11

12 Mass 44 Carbon Dioxide, Nitrous Oxide, Propane Resolution > 8 WSRC-MS Slide 12

13 TRU Waste Drums Initial Movements from Pad Burial Issue Thousands of Drums To Ship to Carlsbad, NM For initial movement, need below LFL Hydrogen Up to 5% Methane Up to 44% Total Non-Methane VOCs - O2 + N2 Vent and Purge - Monitor Full Characterization GC/MS after vent safe Verify Radiological Data X-Ray no liquids, etc. WSRC-MS Slide 13

14 TRU Drums Have Complex VOC Mixtures Restek Silco Canisters are used to collect samples from waste drums and the gases are verified in our laboratory. Full GC/MS scans can take several hours. The spectra were too complex for direct high resolution mass spectral analysis. Several total VOC sensors were evaluated as an alternative field screen and compared to the current column GC w/fid and TCD detection method but they did not provide enough information to determine a reasonable LFL without using a large flash point correction factor to allow for the different types of possible organics that the sensors would detect. hsgbdr Acetone Butanol Methanol Methane 1,1,1-Trichloroethane 2-methyl 2-propanol Ethyl Ether Toluene Hydrogen Methylene Chloride cyclohexanone Trichloroethylene Isopropyl Alcohol M,P-Xylene Benzene (s) 2-hydroxypropanoic acid ,1-Dichloroethane Methyl Ethyl Ketone Ethyl Benzene 3-Butyn-2-ol, 2-methyl Chloroform Acetic acid, 1-methylethyl ester O-Xylene Tetrachloroethylene acetic acid, methyl ester 7-2- Ethanol, 2-butoxy ,1,2-Trichloro-1,2,2-Trifluoroethane 1-Propene, 2-methyl TETRAHYDRO-3-FURANOL methyl-cyclohexane Propane, 2-methyl-1-nitro ,4-Dimethyl-1-heptene Butanal Hexane, 3-methyl ,3,6-Trioxocane Ethyl Acetate ,2-Dichloroethane Methyl Isobutyl Ketone cyclopentanol Number above Trigger WSRC-MS Slide Trigger Maximum

15 Savannah River National Laboratory Future Hydrogen Technology Studies SRTC Became SRNL SRP Nuclear Processes Shutdown separation facilities D&D cleanup completed in many areas Reduction in Force up to 5% from historic high ~12% this year New Missions Allowed Hydrogen Technology Hydride- bed storage Hydrogen Sensors Material Science R&D Opportunities New Lab 66, sq ft Built - Owned by Aiken County Half Rented by DOE for 5 years Outside the Fence uncleared okay! Other Half University and Industry Several auto industries WSRC-MS Slide 15

16 New Hydrogen Technology Research Laboratory 8 modules for Analytical Sensor Development WSRC-MS Slide 16

17 MiniMass Spectroscopy On Hold for FY5 Fast Hydrogen Analysis Mass Sensors, Inc R8 Fast Electrostatic Voltage Sweep Acceleration Fixed Magnetic Field Data Collected Pulse counts Amtek/ORTEC MCS Sweeps in 2 ms Bins.1 ms SERMACS, Nov 24 Some New Funding for FY6 WSRC-MS Slide 17

18 SERMACS 26 Savannah River Section of the American Chemical Society will host the South Eastern Regional Meeting of the American Society [SERMACS] Augusta, Georgia November 1-4, 26 Hope some of you will attend and send your students to give talks and posters. WSRC-MS Slide 18

19 Acknowledgements Charles Crawford Tom White Chris Beam Rob Lascola Laura Tovo Steve Crump WSRC-MS Slide 1