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Pactiter/Corele meeting January 25-26, 2005 Cadarache. OSIRIS neutronic and activation simulation with Scalenea-ANITA in support of PACTITER/CORELE analyses. G. Cambi, D.G. Cepraga, M. Frisoni. Enea & Bologna University Team. Neutronic-activation analysis goals.
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Pactiter/Corele meeting January 25-26, 2005 Cadarache OSIRIS neutronic and activation simulation with Scalenea-ANITA in support of PACTITER/CORELE analyses G. Cambi, D.G. Cepraga, M. Frisoni Enea & Bologna University Team
Neutronic-activation analysis goals • Reaction rates for nuclear reaction relevant for PACTITER simulation of the activation of the corrosion products in CORELE loop • Activity of the AISI 316 tubes irradiated in OSIRIS reactor vs. cooling time (i.e. during different corrosion tests in CORELE loop): total values and relevant isotope values • Comparison of the SCALENEA-ANITA calculation results with experimental data and with CASTOR calculations Enea & Bologna University Team
Calculation Tools SCALENEA-1 Calculation sequence Radiation transport analysis Code sequence: Bonami-Nitawl-XSDNRPM (from Scale) Neutron-gamma data library: Vitenea-E (174n-38g) based on ENDF/B-V and ENDF/B-VI Material activation analysis Activation code: ANITA-2000 Activation data library: EAF-2003 Enea & Bologna University Team
Neutronic schematization Region 1 One homogeneous zone (z1) z1 U235, U238, H2O, Al Region 2 Nine homogeneous zone (z2 to z10) z2, z3, z5, z7 90% H2O, 10% Steel z4, z6, z8 Steel (AISI 316) z9, z10 H2O With this schematization the neutron flux spectra (174 groups) has been calculated and collapsed to obtain three group n flux (same energy boundaries as chosen by OSIRIS team) : Ff (E>1 MeV) Fepith (0.1 MeV<E<1 MeV) Fth (E<0.1MeV) Attention is focused on the Region 2 where 4 test steel tubes (in water box 010) are irradiated for 8 hours Enea & Bologna University Team
ENEA neutronic simulation1 Parameter used to choose zone for tubes irradiation in region 2 I = Ff / Fth Input data considered A(from integrated dose values Jan. 2004) Fth = 1.9E+12 n/cm2 s Eth < 0.1 MeV Ff = 2.4E+11 n/cm2 s Ef > 1 MeV B(updated simulation by Rozemblum Nov. 2004) Fth = 2.25E+12 n/cm2 s Ff = 5.0E+11 n/cm2 s C(older – 2001 - OSIRIS data ) Fth = 2.65E+12 n/cm2 s Ff = 3.5E+11 n/cm2 s IA = 0.126 IB = 0.222 IC = 0.132 zone 5 zone 2 zone 3 Enea & Bologna University Team
ENEA neutronic simulation2 Example of the procedure used to select the zone for neutron flux spectra definition Enea & Bologna University Team
Activation calculation Neutron flux spectra (174 groups) in zones 2, 3, 5 (based on the parameter I) have been considered Input data considered Test tubes data Average tube mass = 127 g SS 316L density = 8.10 kg/dm3 SS 316L composition (mass%): Fe 67.4 Ni 11.2 Co 0.093 Cr 16.77 Mn 1.64 Mo 2.06 Cu 0.29 S 0.01 C 0.012 N 0.07 Si 0.4 P 0.031Irradiation conditions Duration length = 8 hours Total neutron flux zones 2, 3, 5 (n/cm2 s) Ftotz2 = (Ftot/Fth)z2xFth (B) = 3.14E+12 Ftotz3 = (Ftot/Fth)z3xFth (C) = 3.27E+12 Ftotz5 = (Ftot/Fth)z5xFth (A) = 2.31E+12 Others data needed Neutron flux spectraand total neutron fluxfor irradiation Enea & Bologna University Team
Results and comparisons Activity (Bq) for a 127 g SS316L test tube (March 26, 2004) Calculated/experiment Enea & Bologna University Team
Conclusions and …… • For ANITA calculation the case C (z3) provides the lowest discrepancies with respect to the experimental data. • The reaction rates for the PACTITER relevant nuclear reaction have been calculated (for the three neutron spectra z2, z3, z5). • The activity (total and for each relevant isotope) have been calculated for the cooling times relevant for PACTITER/Corele simulation Enea & Bologna University Team
…… future work A more refined neutronic simulation could be obtained with SCALENEA if the following data will be available: • Experimental total neutron flux for the test tubes • irradiation zone • More defined experimental data on neutron fluxes • (i.e. thermal, epithermal, and fast neutron fluxes) • Measures (fluxes and activity) uncertainties Enea & Bologna University Team