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

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

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)

Nuclear Data for Transmutation: status, needs and methods Nuclear power plants generate long lived radiotoxic nuclides through the reactions: n U → fission products +  +  + 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,  ), leads to the Transuranium or Actinides production n U → 239 U +  → 239 Np + n + e- → 239 Pu + n + e- →…… etc. n Pu → 240 Pu +  n Pu → 241 Pu +  → 241 Am + + e -

Nuclear Data for Transmutation: status, needs and methods Americium appears in the nuclear system in two ways: beta decay of 241 Pu 241 Pu → 241 Am +  neutron capture on 242 Pu n Pu → 243 Pu → 243 Am +  241 Am 243 Am T 1/2 1425±100 b   587±12 b Thermal Capture * Data taken from Mughabghab 75.1±1.8 b1820±70 b y 7370 y

Nuclear Data for Transmutation: status, needs and methods * 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% 235 U) Radiotoxicity in spent nuclear fuel *

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

Nuclear Data for Transmutation: status, needs and methods 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 241 Am exist in all recent releases of the available evaluated cross section libraries ENDF, JEFF, JENDL, BROND and CENDL. Cross section status and needs At the very beginning detailed knowledge of the available DATA SETS is very important

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

Nuclear Data for Transmutation: status, needs and methods lib.RRR E - range formulaauthors / year#res., tot, s, neg. EXFOR Data used ENDF/B-VI 1E-5 1.5E2 eVSLBWYoung, Madland, Zhou et al. 195, 190, 5Darrien; Vanpraet; Wisshak JEF 3.0 1E-5 1.5E2 eVSLBWConde et al.190, 189, 1 JENDL 3.3 1E-5 1.5E2 eVMLBWT.Nakagava O.Iwamoto , 190, 5Adamchuk, Derrien and Lucas, Bowman, Gerasimov, Dabbs, Weston and Todd, Vanpraet CENDL 2.1 1E-5 1.5E2 eVZhou Delin, Gu Fuhua et al. 195, 190, 5 BROND 2 1E-5 1.5E2 eVMLBWA.I.Blokhin V.M.Maslov Oct , 189, 1Capture:Vanpraet(VA76) Trans:Phillips(PH79) Recent releases of evaluated files libraries

Nuclear Data for Transmutation: status, needs and methods lib.LAB.EVALUATORSDATE ENDF/B-VI LANL, CNDC Young, Madland, Zhou et al. August 1994 JEF 3.0 NEA H. Conde June 1982 JENDL 3.3 JAERI Nakagava, Iwamoto et al. March 2001 CENDL 2.1 CNDC Zhou Delin, Gu Fuhua et al. June 1992 BROND 2 FEI / IJE Blokhin, Maslov et al. December 1990 ENDF / B-VI.8 Resolved resonance parameters in the energy range 1.0E-5 eV to 150 eV are derrived by means of SLBW formula, and five negative resonances were added JEF 3.0 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. JENDL 3.3 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. BROND 2 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. Evaluated Data Files for 241 Am

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

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

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

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

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.

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

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

Nuclear Data for Transmutation: status, needs and methods Am-241 RRR Average Parameters lib. tt nn  ff ENDF / B-VI JEFF JENDL BROND CENDL

Available Experimental Data Sets Nuclear Data for Transmutation: status, needs and methods Few different ToF capture data sets are available in the resolved resonance region: the (n,abs) data from Weston et al. and Todd et al., the (n,γ) data from Vanpraet et 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.

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.

Nuclear Data for Transmutation: status, needs and methods Energy Range, eV Experimental Technique FacilityDetectorMin. and Max. Uncertaintie s Experimen tal Data # of Ref.Remarks 1.04E4 -2.3E5 Maxon Rae, Plus n/gamma discrimination Van de Graaff, ToF, FZK Karlsruhe Maxon Rae plus Liq. Scintillator 5%-10%CSR:22 Wisshak & Kaeppeler 1980 Cross Section Sum 241 Am(n,g) / 79 Au(n,g) Work /Subwork E-1 – 1.5E5 Total Energy Detector(Mayer -Leibniz weighting) LINAC/ GELINA, ToF C 6 D 6 Liq. Scintillator 0.5% - 10%CS: 7356 Vanpraet et al Cross Section Work/Subwork E2 Transmission and Fission LINAC/Saclay, ToF 10B-NaI plus Liq.Scintillat or Ne226 for neutrons 2% - 5%RP:78 Derrien et al Res. Widths Work/Subwor E-2 - 5E5 Total Energy Detector LINAC/Harwell,ToF Liq. Scintillator tank >10%CS:39 Gayther 1977 Cross Section Work/ Subwork E E Total Energy Detector LINAC/ORELA, ToF Liq. Scintillator, NE226 7%-5%RP:7 Weston 1976 Res. Width Work/S ubwork Neutron Capture EXFOR Data Set for 241 Am

Energy Range, eV Experimental Technique FacilityDetectorMin. and Max. Uncertainties Experimental Data # of Ref.Remarks 9.84E-3 – 3.77E5 Total Energy Detector ToF, LINAC- ORELA Liq. Scintillator, NE226 5%-7%CS:4968 Weston 1975 Cross Section Work/Subwor k Neutron Absorption EXFOR Data Set for 241 Am Neutron Total Cross Section EXFOR Data Set for 241 Am Energy Range, eV Experimental Technique FacilityDetectorMin. and Max. Uncert. Experimental Data # of Ref.Rem. 7.85e e+3 Transmission and Fission LINAC/Sac lay, ToF 10B-NaI plus Liq.Scintillator Ne226 for neutrons 2% - 5%CS:13840 Derrien 1975 Work/Sub work2041 5/ e e+7 LINAC/LL ToF Scintillator???CS:32 T.W.Phillips 1979 Work/Sub work 10763/ e e+2 Abs. Measurement Reactor, ToF He-3 proportional counters ??? CS:2985 T.S.Belanova 1976 Work/Sub work4030 5/ 004 Nuclear Data for Transmutation: status, needs and methods

# Vanpraet et al. Capture cross section 241 Am in a metallic form ToF on LINAC GELINA C 6 D 6 detector (weighted by Meyer- Leibniz ) Neutron flux has been measured through 10 B (n,αγ) 7 Li reaction by two C 6 D 6 detectors. Energy range 6.86E-1 eV – 1.5E5 eV. The total uncertainties of cross section have been estimated up to 7%. Nuclear Data for Transmutation: status, needs and methods # Weston & Todd Absorption cross section Sample in form of AmO 2 ToF on LINAC 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 AmO 2 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.

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

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

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 241 Am resonance data are needed. Nuclear Data for Transmutation: status, needs and methods Resume of 241 Am capture cross section data sets

Nuclear Data for Transmutation: status, needs and methods 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 Americium-243 Capture Cross Sections Data

Evaluated Data Files for 243 Am Nuclear Data for Transmutation: status, needs and methods lib.LAB.EVALUATORSDATE ENDF/B-VILANL, CNDC P.G. Young, L.W. Weston et al. September 96 JEF 3.0NEAH. CondeJune 1982 JENDL 3.3MINSK / JAERIV.M. Maslov, T. Nakagawa et al. January 2002 CENDL 2.1 none BROND 2 FEI / IJE Blokhin, Maslov et al.October 90 The ENDF, JENDL, JEFF and BROND libraries do contain evaluated files for 243 Am. 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 243 Am

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

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

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

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

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

Nuclear Data for Transmutation: status, needs and methods

Unresolved Resonance Region

Nuclear Data for Transmutation: status, needs and methods lib. tt nn  ff ENDF / B-VI E-4 JEF ??? JENDL E-4 BROND E-4 CENDL 2.1 ????????? ????? Am-243 RRR Average Parameters

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

Energy Range, eV Experimental Technique FacilityDetectorMin. and Max. Uncert. Experimenta l Data # of Ref.Rem. 5.7e e4Maxon Rae, Plus n/gamma discrimination NE213 Van de Graaff, ToF, FZK Karlsruhe Maxon Rae, Plus n/gamma discrimination 5% -20% CSR:16 CS:16 Wisshak et al. 9.83e e1 TransmissionLINAC/OR ELA, ToF 6Li glass scintillator 10%RP:23 Simpson et al Work/Subwo rk20415/ eV-1000eV TransmissionLINAC/OR ELA, ToF 6Li glass scintillator Not givenCS:5945 Thin sample b/atom Simpson et al Work/Subwo rk10204/ eV-75.8eV TransmissionLINAC/OR ELA, ToF 6Li glass scintillator Not givenCS:2337 Thick sample b/atom Simpson et al Work/Subwo rk10204/ 004 Nuclear Data for Transmutation: status, needs and methods Available Experimental Data Sets for Am-243

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 been found. In the unresolved resonance region up to 1 MeV there exist only two TOF data sets by Wisshak et al. and Weston et al., ranging from 0.3 keV to 100 keV and 5 keV to 100 keV respectively. No data are available above 100 keV.

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

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

Thank you for attention