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Nuclear Data for Transmutation: status, needs and methods

Nuclear Data for Transmutation: status, needs and methods. Second IP EUROTRANS Internal Training Course Nuclear Data for Transmutation: status, needs and methods , Santiago de Compostela (Spain) June 7 - 10, 2006.

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Nuclear Data for Transmutation: status, needs and methods

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  1. Nuclear Data for Transmutation: status, needs and methods Second IP EUROTRANS Internal Training CourseNuclear Data for Transmutation: status, needs and methods,Santiago de Compostela (Spain) June 7 - 10, 2006 Review of the available experimental and evaluated capture cross section data for 241Am and 243Am Nikola Vasilev, Institute for Nuclear Researches and Nuclear Energy, Bulgarian Academy of Sciences

  2. Nuclear Data for Transmutation: status, needs and methods Introduction • Nuclear Waste • Minor actinides • Americium • Radiotoxicity & Solutions Objectives • Cross section data • AvailableEvaluated Data Files for Americium • Available Experimental Data for Americium

  3. Nuclear Data for Transmutation: status, needs and methods Spent Nuclear Fuel Waste • Elements with more than 92 protons: Transuranium elements (TRU) • Fission products • Neptunium, americium & curium: Minor Actinides (MA)

  4. Nuclear Data for Transmutation: status, needs and methods • Nuclear power plants generate long lived radiotoxic nuclidesthrough the reactions: • n + 235U → fission products+ g + n + e-+ n The fission reaction is however not the only reaction that can result from neutron absorption in uranium. The capture reaction, denoted as (n,g), leads to the Transuranium or Actinides production • n + 238U → 239U + g→ 239Np + n +e- → 239Pu + n + e- →…… etc. • n + 239Pu → 240Pu + g • n + 240Pu → 241Pu + g→ 241Am + n + e-

  5. Americiumappears in the nuclear system in two ways: Nuclear Data for Transmutation: status, needs and methods beta decay of 241Pu 241Pu 􀃷 →241Am + b neutron capture on 242Pu n + 242Pu 􀃷 → 243Pu →􀃷 243Am +b T1/2 I g Thermal Capture 241Am 432.2 y 1425±100b 587±12 b T1/2 I g Thermal Capture 243Am 1820±70 b 75.1±1.8 b 7370 y *Data taken from Mughabghab

  6. Nuclear Data for Transmutation: status, needs and methods Radiotoxicity in spent nuclear fuel * * The radiotoxicity values are relative to the radiotoxicity (horizontal line) of the quantity of uranium ore that was originally mined to produce the fuel (eight tons of natural uranium yields one ton of enriched uranium, 3.5% 235U)

  7. Nuclear Data for Transmutation: status, needs and methods Possible Solutions Repository : How long is it possible to be stored? Isn’t it Very hazardous? Probably the more sophisticated and clever way is Transmutation in existing facilities like HWR & LWR or Accelerator Driven Systems and Fast Reactors

  8. Nuclear Data for Transmutation: status, needs and methods Cross section status and needs Accurate and reliable neutron capture cross section data for MA are necessary for the proper design, safety regulation and precise performance assessment of transmutation. At the present moment evaluated cross section files for 241Am exist in all recent releases of the available evaluated cross section libraries ENDF, JEFF, JENDL, BROND and CENDL. At the very beginning detailed knowledge of the available DATA SETS is very important

  9. Nuclear Data for Transmutation: status, needs and methods Americium 241 Capture Cross Sections Data • Thermal Energy Range • 1 / v • Up to 0.15 eV • Resolved Resonances • 190 number of resonances are observed • RR Range: • 0.15 eV to 150eV • Unresolved Resonance • RR Range: • 150eV up to 4000eV

  10. Nuclear Data for Transmutation: status, needs and methods Recent releases of evaluated files libraries

  11. JENDL 3.3 ENDF / B-VI.8 Resolved resonance parameters in the energy range 1.0E-5 eV to 150 eV are derrived by means of MLBW formula, and five negative resonances were added. The resonance parameters were adopted by Maslov which were mainly taken from Darrien et al. transmission measurements. Resolved resonance parameters in the energy range 1.0E-5 eV to 150 eV are derrived by means of SLBWformula, and five negative resonances were added JEF 3.0 BROND 2 Resolved resonance parameters in 1.0E-5 eV to 150 eV, The RRP were adopted by means of SLBW formula and one negative resonance was added. Resolved resonance parameters in 1.0E-5 eV to 150 eV, data were taken from JENDL 3.0 with small corrections. The RRP were adopted by means of MLBW formula and one negative resonance was added. Nuclear Data for Transmutation: status, needs and methods Evaluated Data Files for 241Am

  12. Nuclear Data for Transmutation: status, needs and methods Most recent releases of evaluated (n,γ) cross section in thermal and resonance energy region

  13. Nuclear Data for Transmutation: status, needs and methods Comparison between ENDF/B-VI.8 and BROND 2.2, MT=102, energy region 20eV - 40eV 6 times higher

  14. Nuclear Data for Transmutation: status, needs and methods Shape and amplitude difference as well as energy shifting between the evaluated files for MT=102

  15. BROND vs. ENDF/B-VI.8 in energy range 140eV-150ev, MT=102 Nuclear Data for Transmutation: status, needs and methods

  16. Nuclear Data for Transmutation: status, needs and methods Unresolved Resonance Region Due to the lack of experimental data in the unresolved resonance region, the discrepancy of the evaluated data from the different libraries become more visible, since it is 5% up to 20keV and 10% or larger above.

  17. Nuclear Data for Transmutation: status, needs and methods Resolved & Unresolved resonance region

  18. Nuclear Data for Transmutation: status, needs and methods RRR Significant differences are found in the resolved resonance region • up to 30eV mainly in the shape of the resonances • The evaluated file from BROND contains few strong resonances that are not included into the other libraries URR • the discrepancy of the evaluated data from the different libraries become more visible in UnresolvedResonanceRegion , since it is 5% up to 20keV and 10% or larger above.

  19. Nuclear Data for Transmutation: status, needs and methods Am-241 RRR Average Parameters

  20. Nuclear Data for Transmutation: status, needs and methods Available Experimental Data Sets • Few different ToF capture data sets are available in the resolved resonance region: the(n,abs) data from Westonet al. and Todd et al., the (n,γ) data from Vanpraetet al.and the (n,γ) measurements of Gayther et al. • In the unresolved resonance region the above mentioned data as well as the data of Wisshak & Kaeppeler are available. • No experimental data above 400keV are available except few activation measurements as well as 9 data points (n,γ) measurement of Florov in energy range from 3e5 eV to 6.80e5 eV.

  21. Nuclear Data for Transmutation: status, needs and methods • The uncertainties in these measurements vary between 0.5 and 10% (>10% Gayther data set). • Into the lower energies of resolved resonance region (first few resonances) a large difference between Vanpraet data and other data sets was found, as the difference is up to 30% . • This difference should be due to the not correct self shielding effects account or not enough correct application of weighting technique. • Additional resonance parameters can be found in Weston measurements and in transmission/fission measurements of Derrien at el.

  22. Nuclear Data for Transmutation: status, needs and methods Neutron Capture EXFOR Data Set for 241Am

  23. Nuclear Data for Transmutation: status, needs and methods Neutron Absorption EXFOR Data Set for 241Am Neutron Total Cross Section EXFOR Data Set for 241Am

  24. Nuclear Data for Transmutation: status, needs and methods Nuclear Data for Transmutation: status, needs and methods • # Vanpraet et al. • Capture cross section • 241Am in a metallic form • ToF on LINAC GELINA • C6D6 detector • (weighted by Meyer- Leibniz) • Neutron flux has been measured through • 10B (n,αγ) 7Li reactionby two C6D6 detectors. • Energy range 6.86E-1 eV – 1.5E5 eV. • The total uncertainties of cross section have been estimated up to 7%. • # Weston & Todd • Absorption cross section • Samplein form of AmO2 • ToF onLINAC ORELA in Oak Ridge • Liquid scintillators NE226(weighted by Macklin & Gibbons approach) • Neutron flux from thermal energies to 2keV has been monitored by a 10BF3 ionization chamber. • Energy range from 0.01eV to 20keV • The total uncertainties are between 5% and 7%. • # Wisshak & Kappeler • Capture cross section • Samples from AmO2 • ToF on 3 MV Van de Graaff in Forzshungtzentrum Karlsruhe • Maxon Rae detector and liquid scintillator • Detailed description of the uncertainties, that are in 5% and 10% range.

  25. ToF capture data sets available in the Resolved Resonance Region Nuclear Data for Transmutation: status, needs and methods

  26. Nuclear Data for Transmutation: status, needs and methods ToF capture data sets available in the Unresolved Resonance Region

  27. Nuclear Data for Transmutation: status, needs and methods Resume of 241Am capture cross section data sets • There are discrepancies in the evaluated files from different libraries. • For a conceptual design and safety operation of transmutation devices it is required to be clarified the origin and reasons for them. • The accuracy of evaluated data files should corresponds to the design requirements. • New top accuracy measurements and sophisticated analysis of 241Am resonance data are needed.

  28. Nuclear Data for Transmutation: status, needs and methods Americium-243 Capture Cross Sections Data • Thermal Energy Range • 1 / v • Up to 0.20 eV • Resolved Resonances • 220 number of resonances are observed • RR Range: • 0.20 eV to 250eV • ( 0.20eV to 210ev • in BROND 2 ) • Unresolved Resonance • RR Range: • 250eV up to 4000eV

  29. Evaluated Data Files for 243Am Nuclear Data for Transmutation: status, needs and methods • The ENDF, JENDL, JEFF and BROND libraries do contain evaluated files for 243Am. • No evaluated file exists from the CENDL cross section library • The discrepancies between libraries in the unresolved resonance region and resolved resonance region are significant. JENDL 3.3 contain the latest evaluated file for 243Am

  30. Nuclear Data for Transmutation: status, needs and methods Most recent releases of evaluated (n,γ) cross section For Am-243 in thermal and resonance energy region

  31. Nuclear Data for Transmutation: status, needs and methods JENDL 3.3 vs. ENDF/B-VI.8 in energy range 90 eV-110eV, MT=102

  32. Nuclear Data for Transmutation: status, needs and methods JENDL 3.3 vs. ENDF/B-VI.8 in energy range 190 eV - 220eV, MT=102

  33. Nuclear Data for Transmutation: status, needs and methods JENDL 3.3 vs. ENDF/B-VI.8 in energy range 130 eV – 255 eV, MT=102

  34. Nuclear Data for Transmutation: status, needs and methods BROND vs. JENDL 3.3

  35. Nuclear Data for Transmutation: status, needs and methods

  36. Nuclear Data for Transmutation: status, needs and methods Unresolved Resonance Region

  37. Nuclear Data for Transmutation: status, needs and methods Am-243 RRR Average Parameters

  38. Nuclear Data for Transmutation: status, needs and methods Preliminary analysis of Resonance parameters of 243Am (data taken from JENDL 3.3)

  39. Nuclear Data for Transmutation: status, needs and methods Available Experimental Data Sets for Am-243

  40. Nuclear Data for Transmutation: status, needs and methods The amount of available data for 243Am(n,γ) is scarce. In the resolved resonance region,experimental radiative widths have been obtained indirectly from transmission measurements of Simpson et al.and few fission ToF measurements . No direct ToF capture cross section data have beenfound. In the unresolved resonance region up to 1 MeV there exist only two TOF data sets byWisshak et al. and Weston et al., ranging from 0.3 keV to 100 keV and 5 keV to 100 keVrespectively. No data are available above 100 keV.

  41. Nuclear Data for Transmutation: status, needs and methods Resume of 243Am capture cross section data sets JENDL 3.3 contain the latest evaluated file for 243Am • Energy Shifting between JENDL 3.3 and other libraries • Large Shape Differences • Discrepancies in Resonance Parameters between Libraries • Lack of Experimental Data

  42. Nuclear Data for Transmutation: status, needs and methods New top accuracy measurements and sophisticated analysis of 243Am resonance data ARE HIGHLY NEEDED .

  43. Nuclear Data for Transmutation: status, needs and methods Thank you for attention

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