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Neutron Activation Analysis at the Radiochemical Laboratory, Institute of Nuclear Techniques , Budapest University of Technology and Economics N. Vajda, Zs. Molnár, M. Balla, D. Bódizs, IWIRad Bucharest, 20-21 June 2005. Contents. Facility INAA –accredited procedure uncertainty budget

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  1. Neutron Activation Analysis at the Radiochemical Laboratory,Institute of Nuclear Techniques,Budapest University of Technology and Economics N. Vajda, Zs. Molnár, M. Balla, D. Bódizs,IWIRadBucharest, 20-21 June 2005

  2. Contents • Facility • INAA –accredited procedure uncertainty budget method validation Application examples: geological samples archaeological samples biological samples • RNAA analysis of 129I

  3. Equipment for the measurement of trace elements by NAA γ spectrometer training reactorpneumatic transport Фth= 2E12 /s/cm2 system

  4. Radiochemical laboratories for „high” activity samples for low activity samples hot cell facility for processing irradiated samples

  5. NAA in numbers • Training reactor vertical irradiation channels with several thermal irradiation positions rabbit system with 2 irradiation positions φth: 2.6E12/cm2/s (100 kW, thermal channel) φth/φepi: 26-33 (100 kW, thermal channel) • HPGe detectors and MCAs efficiency: resolution: well type Ge 14 % 1.95 keV POP-TOP Ge 22 % 2.5 keV • MCA: S100 (16k), Accuspec B (8k) • SAMPO 90, Gennie 2000

  6. INAA • Comparator technique: Au comparator Zr flux monitor • Standard conditions: sample preparation • irradiation • measurement • standardization

  7. Sample preparation: Irradiation: Measurement: flux variation, the, irr. time weighing :sample, gold, Zr humidity, impurities of vials counting statistics, geometry, dead time, timing, background canalyte Standardisation Uncertainty budget / major sources of uncertainty: counting statistics: 0.2-30 %; k factors: 2-7 %

  8. Uncertainties of k factors

  9. QC Analysis of SRMs FA fly ash, S7 soil-7 MS marine sediment

  10. QC Analysis of SRMs

  11. Ce

  12. Method validation: inter- comparison exercise

  13. Method validation: inter- comparison exercise

  14. Analysis of steel BSS3 (intercomparison) Element Average σ (k=2) Mn % 1,88 +- 0,1 Cu % 1,08+- 0,2 V ppm 704 +- 50 Cr % 25,6+- 1 Sb ppm 5,2+- 0,3 As ppm 25,8 +- 2 Fe % 37,5 +- 1,5 Co ppm 398 +- 20 Ni % 29,4 +- 2 W ppm 69 +- 3 Mo % 3,24 +- 0,5

  15. APPLICATION EXAMPLE: INAAAnalysis of archaeological samples Fingerprinting of archaeological ceramic materials: Multivariate statistical methods using trace element data for provenance studies of ceramics. Terra sigillata ceramics used in Aquincum were not locally manufactured.

  16. Jan Gunneweg, MartaBalla The Provenance of Qumran Pottery by Instrumental Neutron Activation Analysis COST G8 Qumran Meeting 21-23 May 2005

  17. Main goals to trace pottery by its chemistry to their place(s) of manufacture to establish the relation between pottery found in the settlement and the caves to study what pottery was locally made and which was brought in from elsewhere to learn the interregional contact between Qumran and its surroundings COST G8 Qumran Meeting 21-23 May 2005

  18. Sample selection • Qumran reference samples • Clay and ceramic samples from Jericho, Jerusalem, Hebron, Callirhoe, ‘Ain Feshkha • 166 pottery samples from the settlement and the caves COST G8 Qumran Meeting 21-23 May 2005

  19. Analytical results evaluated by multivariate statistics COST G8 Qumran Meeting 21-23 May 2005

  20. Most important results and archaeological conclusions • Qumran’s local chemical fingerprint has been defined • 5 chemically different groups of pottery were determined and their probable provenance have been localized • Analysis of clay and ceramic samples from other sites of the Dead Sea region provided reference data for workshop assignment • Pottery serves as a connecting link between the settlement and the caves COST G8 Qumran Meeting 21-23 May 2005

  21. APPLICATION EXAMPLE: INAAAnalysis of geological samples mineral separates, bulk rocklanthanides and other incompatible trace elements Processes of igneous petrogenesis, paleotectonic and paleogeographic position of rocks Typical detection limits:

  22. APPLICATION EXAMPLE: INAAAnalysis of biological samples brain biopsy samples to study Alzheimer deseasealkali metals + iodine Uncertainties LD INAA ICPMS ICPAES INAA ICPMS ICPAES unc% STD% unc% STD% unc% STD% Li(ng/g) - - 3 32 5 28 3 1 Na(ug/g) 1 2 5 8 40 2 K(ug/g) 5 3 2 6 1300 90 Rb(ug/g) 5 4 2 11 0,6 0,02 Cs(ng/g) 10 5 5 24 7 20 I(ng/g) 7 Good reproducibility in INAA!

  23. RNAAfor the analysis of radionuclides • Long-lived • „difficult to determine nuclides„ • (DDN) • in the nuclear fuel cycle • e.g. 129I T1/2=1.57E7 y • 129I(n,γ)130I T1/2=12.4 h • 99Tc T1/2=2.13E5 y • 99Tc(n,γ)100Tc T1/2=15.8 s • Too short! Methods: α spectrometry β spectrometry γ spectrometry RNAA

  24. Radiochemical separation procedure for the simultaneous separation of DDNs 129I 99Tc Ni Pu-Np-U Sr Am-Cm

  25. APPLICATION EXAMPLE: RNAA 129I analysis: - Ground level measurements in well water on the site of the future radioactive waste disposal area: analysis of 100 L of water <μBq/L - Analysis of nuclear wastes: evaporation concentrates: 10-100 mBq/L spent ion exchange resins: 1-10 Bq/L

  26. Accredited procedures: • γ spectrometry • Determination of Gamma Emitting Fission and • Corrosion Nuclides in NPP Primary Coolant by • Gamma Spectrometry • Determination of Activity Concentration of Nuclear • Power Waste by Gamma-Spectrometry • Determination of Activity Concentration of • Environmental Samples by Gamma-Spectrometry • NAA • NAA of geological and environmental samples • NAA of archaeological potteries • α and β spectrometries • Analysis of Uranium, Plutonium, Americium, • Curium, Nickel and Strontium Nuclides in • Radioactive Wastes • Determination of Strontium and Plutonium Isotopes • in Concentrates of Water Samples

  27. Staff: N. Vajda, Zs. Molnár, M. Balla, D. Bódizs, Gy. Csuday, J. Szabó, K. JoviczaPhD students: A. Kerkápoly, Sz. Osváth, É. Kabai, D. Tar, G. Surányi

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