Research Seminar. Radiochemical Analysis of Plutonium in Tissues from Former Nuclear Workers

Transcription

1 Research Seminar Oregon State University, School of Nuclear Science and Engineering November 27, 2017 Radiochemical Analysis of Plutonium in Tissues from Former Nuclear Workers Sergei Y. Tolmachev and George Tabatadze United States Transuranium and Uranium Registries College of Pharmacy, Washington State University 1845 Terminal Drive, Suite 201, Richland, WA Learning from Plutonium and Uranium Workers

2 Outline U.S. Transuranium and Uranium Registries Radiochemistry at the USTUR Plutonium in human

3 U.S. Atomic Energy Commission Vision 1966 meeting Plutonium Contamination in Man to protect the interests of workers, employees, and the public by. the acquisition and provision of the latest and most precise information about the effects of the transuranic elements on man.

4 National Plutonium Registry: Blue Ribbon Committee Standing left to right: Carlos E. Newton, Jr., W. Daggett Norwood, H.D. Bruner, Philip A. Fuqua Seated left to right: Thomas F. Mancuso, J.H. Sterner, Robley D. Evans, Herbert M. Parker Not photographed: Clarence C. Lushbaugh, Lloyd M. Joshel

5 Genealogy of the USTUR REGISTRIES MANAGEMENT ANALYTICAL SUPPORT 1968 National Plutonium Registry Rocky Flats Pacific Northwest at Hanford Environmental Health Foundation Facility Laboratory 1970 United States Transuranium Registry at Hanford Environmental Health Foundation 1971 Los Alamos National Laboratory 1978 United States Uranium Registry at Hanford Environmental Health Foundation United States Transuranium and Uranium Registries at College of Pharmacy, Washington State University

6 USTUR Mission Follow up occupationally exposed individuals (nuclear workers) by studying the biokinetics (uptake, translocation, retention, and excretion), and dosimetry of actinides (uranium, plutonium, americium) Refine internal radiation dose assessment methods as the bases for reliable epidemiological studies, risk projection, and credible standards for radiological protection Assess adequacy of historical and current U.S. regulatory controls and practices

7 USTUR Today Unique resource worldwide for the comprehensive study of the biokinetics and internal dosimetry of actinide elements in the human body National Human Radiobiology Tissue Repository The USTUR has provided important scientific information to ensure the adequacy of the safety standards for these radioactive elements

8 Primary Research: Biokinetic Modeling and Dosimetry of Actinides Model development, validation, and parameterization Inhalation i. Americium Oxide (AmO 2 ) ii. Plutonium Oxide (PuO 2 ) iii. Plutonium Nitrate [Pu(NO 3 ) 4 ] iv. Uranium Hexafluoride (UF 6 ) Wound i. Americium Nitrate [Am(NO 3 ) 3 ] ii. Plutonium Nitrate [Pu(NO 3 ) 4 ] iii. Plutonium Oxide (PuO 2 ) Ca-EDTA/DTPA Chelation i. Americium Oxide (AmO 2 ) ii. Plutonium Nitrate [Pu(NO 3 ) 4 ] Courtesy of W.J. Bair

9 USTUR Registrants (I) Voluntary tissue donors (posthumous): whole-(44) and partial-body (307) donations Former nuclear workers from DOE sites

10 USTUR Registrants (II) Documented radiation exposure and work history Acceptance criteria: i. actinide internal deposition of 74 Bq (2 nci) ii. external dose to whole body 0.1 Sv (10 rem)

11 Primary Exposure

12 USTUR Donations

13 USTUR Operation Autopsy Tissue Collection Radiochemical Analysis Biokinetic Modeling Drying and Ashing Digestion and Dissolution Radionuclide Separation α-source Preparation Actinide Measurements

14 Radiochemistry at USTUR Laboratory Facilities NHRTR Radiochemical Tissue Analysis Plutonium in Human

15 USTUR Laboratory Building Office Autopsy Lab Chemistry Lab Counting Room Drying/ashing room Sample storage area 6,500 sq. ft. facility

16 Autopsy Laboratory MORTECH Mortuary Refrigerator MORTECH Autopsy Station and Elevating Table

17 Tissue Ashing Room VWR 1685 HAFO Series Forced-Air Oven, Fisher Scientific Isotempâ Muffle Furnace 550 Series, LINDBERG Muffle Furnace Model 52641

18 Radiochemistry Laboratory

19 Counting Room

20 Sample Storage Area

21 National Human Radiobiology Tissue Repository Established in 1992 Resources for radiation dosimetry and biological effects studies USTUR frozen-tissue collection:

22 Tissue Sample Analysis Protocol Drying/Ashing Digestion/Dissolution Radionuclide Separation α-source Preparation Actinide Measurements (Alpha-Spec)

23 USTUR 106: Sample Drying and Ashing 100 C for 4 days, max. 48 samples 450 C for 4 days ( 2), max. 32 samples

24 USTUR 110: Sample Digestion Microwave Digestion Soft tissue: HNO3 HCl HF, 9:3:4 (ml) Bone: HNO3 HCl, 10:3 (reverse aqua regia) Controlled temperature: 220 C Monitored pressure: 40 bar Radiochemical tracers (NIST): 242 Pu, 243 Am, 232 U MARS-5 Microwave EasyPrep Vessel

25 DGA TRU TEVA USTUR 350: Actinide Separation Vacuum-Assisted Extraction Chromatography

26 USTUR 350: Actinide Separation (Pu) 1) Sample in 40 ml 3M HN0 3 1M Al(NO 3 ) 3 2) Add 0.75 ml 1.5M Sulfamic Acid + 6 ml 0.75M Ascorbic Acid 3) Add 2.5 ml 3.5 M Sodium Nitrite 4) Sample loading (1 drop sec -1 ) 5) Beaker rinse: 2 5 ml 3M HNO 3 6) Separate cartridges 7) TEVA rinse: 30 ml 3M HNO 3 8) Rinse: 20 ml 9M HCl (Th) 9) Pu Elution: 20 ml 0.1M HCl M HF 0.04M Rongalite 1 ml TEVA Resin ( µm) 1 ml TRU-Resin ( µm) (6) Electrodeposition 1 ml DGA-Resin ( µm) Alpha spectrometry Discard (4 8)

27 USTUR 350: Actinide Separation (Am) TRU DGA cartridges from Step 6 10) Am to DGA: 15 ml 4M HCl 11) Separate cartridges 12) Rinse: 3 ml 1M HNO 3 13) Rinse: 10 ml 0.1M HNO 3 (U) 14) Am Elution: 10 ml 0.25M HCl 1 ml TRU-Resin ( µm) (11) 1 ml DGA-Resin ( µm) 1 ml DGA-Resin ( µm) (14) Discard (10) Discard (12,13) Electrodeposition Alpha spectrometry

28 USTUR 350: Actinide Separation (U) TRU cartridge from Step 11 15) Rinse: 12 ml 2.0 M HCl 0.2M HF (Th) 16) U Elution: 15 ml 0.1M Ammonium Bioxalate (16) Discard (15) Electrodeposition Alpha spectrometry

29 USTUR 520: Electrodeposition Phoenix EP-12 Series electrodeposition unit Custom Electrolytic Cell Na 2 SO 4 electrolyte solution 1 hr 0.75 A α-source: 5/8 stainless steel disk (planchet)

30 USTUR 600: Alpha-Spectrometry ORTEC: Ensemble (3) and Octête PC (3) systems Detector: ENS-U450 (48) Software: AlphaVision Calibration: E&Z Analytics (1); USTUR (8) Sample count time: 150,000 s

31 USTUR Case Analysis Timeline 1 2 Weeks Drying 2 weeks Ashing 2 3 Weeks Digestion/Dissolution 48 Tissue Samples 1 week Radionuclide Separation 2 weeks α-source Preparation 2 weeks Actinide Measurements ~ 10 weeks

32 Tissue Analysis Throughput Samples Analyzed

33 Plutonium in Tissues of Occupationally Exposed Individuals

34 Deposition and Retention in Human Body Pu intake Bloodstream Systemic deposition Liver (45%) Skeleton (45%) Soft tissues (10%)

35 Deposition and Retention in Human Body Inhalation Insoluble material Respiratory Tract + Systemic Respiratory tract (major) Systemic deposition (minor)

36 Route of Intake

37 239 Pu Activity Concentration: Lung Range ,225 Geometric Mean % CI for Mean Median % CI for Median Bq kg -1

38 239 Pu Activity Concentration: LNTH Range ,400 Geometric Mean % CI for Mean Median % CI for Median Bq kg -1

39 239 Pu Activity Concentration: Liver Range Geometric Mean % CI for Mean Median % CI for Median Bq kg -1

40 239 Pu Activity Concentration: Skeleton Range Geometric Mean % CI for Mean Median % CI for Median Bq kg -1

41 Summary: 239 Pu Activity Concentration Skeleton < Liver Lung << LNTH

42 239 Pu Activity Concentration in Organs: USTUR vs Mayak PA

43 Hanford Site vs Mayak Hanford 586-square-miles of shrub-steppe desert in southeastern Washington State In 1943, site was used to produce plutonium for the bomb Continued operation during the cold war Last reactor ceased operation in 1987 Site clean up operation present Mayak The Mayak Production Association Built between Secret Soviet Union atomic bomb project Five nuclear reactors Plutonium for weapons Later reprocessing spent nuclear fuel from nuclear reactors Mayak is still active as of

44 LNTH-to-Lung: 239 Pu Concentration Ratio LNTH : Lung > 19 ICRP Type S Range Geometric Mean % CI for Mean Median % CI for Median

45 Skeleton-to-Liver: 239 Pu Activity Ratio 1:1 (Systemic Model Assumption) Range Geometric Mean % CI for Mean Median % CI for Median

46 USTUR: Take Home Message In-depth study of actinide biokinetics and dosimetry Unique resource of data from former nuclear workers Obtain, analyze, and preserve tissue samples for future research Significant impact on national and international radiation protection advisory bodies 50-y research funded by U.S. DOE

47 Questions?