G. Cambi, D.G. Cepraga, M. Frisoni Presented by L. Di Pace (ENEA C.R. Frascati)

1Kick Off Meeting of the contracts TW5-TSS-SEA5.6., TW5-TSS-SEA5.5.D8-9 - CEA Cadarache. October 26th, 2005 Enea & Bologna University Team

G. Cambi, D.G. Cepraga, M. Frisoni

Presented by L. Di Pace (ENEA C.R. Frascati)

OSIRIS neutronic and activation simulationwith Scalenea-ANITA

in support of PACTITER/CORELE analysesTask No. TW5-TSS-SEA4.1

KOM of the contracts TW5-TSS-SEA5.6., TW5-TSS-SEA5.5.D8-9

October 26, 2005Cadarache


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


Calculation Tools

SCALENEA-1Calculation

sequence

Radiation transport analysis

Code sequence:Bonami-Nitawl-XSDNRPM(from Scale)Neutron-gamma data library:Vitenea-E (174n-38)based on ENDF/B-Vand ENDF/B-VI

Material activation analysis

Activation code:ANITA-2000Activation data library:EAF-2003


Neutronic schematization

Region 1(OSIRIS Core)

(Experimental area)

Region 2

Region 1 Region 2

z1 z2

z3

z4

z5

z6

z7

z8

z9

z10

Region 1One homogeneouszone (z1)z1 U235, U238, H2O, Al

Region 2Nine homogeneouszone (z2 to z10)z2, z3, z5, z790% H2O, 10% Steelz4, z6, z8 Steel (AISI 316)z9, z10 H2O

With this schematization the neutron flux spectra (174 groups) has been calculatedand collapsed to obtain three group n flux (same energy boundaries as chosen by OSIRIS team) :f (E>1 MeV) epith (0.1 MeV<E<1 MeV) th (E<0.1MeV)

Attention is focused on the Region 2 where 4 test steel tubes (in water box 010)were irradiated for 8 hours


ENEA neutronic simulation1

Input data considered

A (from integrated dose values Jan. 2004) th = 1.9E+12 n/cm2 s Eth < 0.1 MeV f = 2.4E+11 n/cm2 s Ef > 1 MeV

B (updated simulation by Rozemblum Nov. 2004) th = 2.25E+12 n/cm2 s f = 5.0E+11 n/cm2 s

C (older – 2001 - OSIRIS data ) th = 2.65E+12 n/cm2 s f = 3.5E+11 n/cm2 s

Parameter used to choose zonefor tubes irradiation in region 2

I = f / th

IA = 0.126

IB = 0.222

IC = 0.132

zone 5

zone 2

zone 3


ENEA neutronic simulation2

Region Zone

(E > 1MeV) 0.1 MeV < E < 1 MeV th (E < 0.1 MeV) Total

1 1 7,64E+00 5,86E+00 1,80E+01 3,15E+01

2 2,76E+00 2,15E+00 1,24E+01 1,74E+01 0,2223 1,23E+00 9,56E-01 9,32E+00 1,15E+01 0,1324 5,80E-01 4,20E-01 4,34E+00 5,34E+00 0,134

5 3,59E-01 2,50E-01 2,85E+00 3,46E+00 0,1266 2,18E-01 1,47E-01 1,25E+00 1,62E+00 0,174

7 5,99E-02 3,68E-02 4,15E-01 5,11E-01 0,144

8 1,03E-02 5,42E-03 4,68E-02 6,26E-02 0,221

9 3,07E-03 1,45E-03 2,23E-02 2,68E-02 0,138

10 3,05E-04 1,16E-04 1,90E-03 2,32E-03 0,160

2

Neutron flux (arbitrary units) I

Example of the procedure used to select the zone for neutron flux spectra definition


Activation calculation

Input data consideredTest tubes dataAverage tube mass = 127 gSS 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 conditionsDuration length = 8 hours

Others data neededNeutron flux spectra and total neutron flux for irradiation

Neutron flux spectra(174 groups) in zones 2, 3, 5 (based on the parameter I)have been considered

Total neutron flux zones 2, 3, 5 (n/cm2 s)

totz2 = (tot/th)z2 x th (B) = 3.14E+12

totz3 = (tot/th)z3 x th (C) = 3.27E+12

totz5 = (tot/th)z5 x th (A) = 2.31E+12


Results and comparisons

CASTOR ANITA-2000 Isotope

Experiment (26-3-2004) A B B (z2) C (z3) A (z5)

Co-60 1.13 E+07 9.95 E+06 1.18 E+07 7.05 E+06 9.61 E+06 7.18 E+06 Co-58 1.20 E+07 3.30 E+06 6.96 E+07 1.43 E+07 1.04 E+07 7.71 E+06 Mn-54 1.72 E+06 6.90 E+05 1.43 E+06 2.05 E+06 1.51 E+06 1.13 E+06 Fe-59 1.49 E+07 1.27 E+07 1.51 E+07 7.91 E+06 1.09 E+07 8.20 E+06 Cr-51 7.00 E+08 6.00 E+08 7.11 E+08 3.99 E+08 5.63 E+08 4.24 E+08

Activity (Bq) for a 127 g SS316L test tube (March 26, 2004)

CASTOR ANITA-2000 Isotope

Experiment (26-3-2004) A B B (z2) C (z3) A (z5)

Co-60 1 0.88 1.04 0.62 0.85 0.64 Co-58 1 0.28 5.80 1.19 0.87 0.64 Mn-54 1 0.40 0.83 1.19 0.88 0.66 Fe-59 1 0.85 1.01 0.53 0.73 0.55 Cr-51 1 0.86 1.02 0.57 0.80 0.61

Calculated/experiment


Results and comparisons

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


Irradiated tube decay calculations in support of new PACTITER simulations

To support new PACTITER runs, other activation calculation with ANITA-2000 have been performed. Calculations refer to cooling times evaluated since the irradiation in OSIRIS on 26/1/2004 (because no new irradiation in OSIRIS are foreseen at the moment).

year date Cooling times since 26/1/2004 irradiation

[days] 20/1/2005 360 20/4/2005 450 20/7/2005 541 20/8/2005 572 20/9/2005 603 20/10/2005 633 20/11/2005 664

2005

20/12/2005 694 20/1/2006 725 20/2/2006 756 20/3/2006 784 20/4/2006 815 20/5/2006 845 20/6/2006 876 20/9/2006 968

2006

20/12/2006 1059 20/3/2007 1149 20/6/2007 1241 20/9/2007 1333

2007

20/12/2007 1424 2008 20/12/2008 1790


Results of tubes decay calculations

1

Element Abundance

(%)

Natural isotope Reaction Activation

products

Half-life

(days)

Co 100 59Co (n, ) 60Co 1925

Ni 68 58Ni (n, p) 58Co 71

Cr 4.35 50Cr (n, ) 51Cr 28

0.3 58Fe (n,) 59Fe 45 Fe

5.8 54Fe (n,p) 54Mn 313

From CEA Tech. Report DTN/STRI/LTCD 04-020 (26 janvier 2005)

Release rate ( mg / dm² / month ) Test

Temperature

°C

Velocity

m /s Species

in part total

Ni 4.7 ± 0.9

Co (60Co) 6 10-2 ± 1 10-2

Fe 16. ± 3 4.12

Cr 1 ± 0.4

22 ± 3

Ni 8.1 ± 0.7

Co 1 10-1 ± 0.2 10-1

Fe 27 ± 2

ITER

2004- 01

150

1.09

Cr 0.27 ± 0.12

36 ± 2

Ta b

l e 5

Par

t of

Ta b

l e 1

2


Results of tubes decay calculations2

At the present time, Cr-51 (from Cr) has decreased from four to five orders of magnitude, Co-58 (from Ni) of a factor ~100, Fe-59 (from Fe) of a factor ~1000 and Mn-54 (from Fe as well) of a factor ~3.


Results of tubes decay calculations3

• Considering the activity trapped in the resins for each nuclide during the 2004 CORELE experiments, Cr-51 and Fe-59 were not detected in the resins in tests 02 and 03 due to reduced release rate of their father, but to such minor extent to their decay.

• The decay effect, after about two years from the irradiation, might cause difficulties in detecting radionuclides such as Co-58 and Fe-59. While Fe-59 can be replaced by Mn-54 for calculating Fe release rate, the inability in detecting Co-58, can cause to neglect the contribute of Ni to the overall material release rate.

Mn 54 312 days 834.8 (100)Co 58 70.8 days 511 (29.9) 864 (0.68) 1675 (0.52) 810.8 (99.4)Co 60 5,27 years 1173 (100) 1332 (100)Cr 51 27.7 days 320 (9.85)Cu 64 12.7 hours 511 (36) 1346 (5)Fe 59 44.6 days 192 (3) 1099 (57) 1292 (43)Mn 56 2.58 hours 847 (99) 1810 (27) 2113 (14)Co 57 271.8 days 14 (9.5) 122 (85.6) 137(10.6)Ni 57 36.1 hours 127 (16) 1378 (80) 1757 (6.1) 1919 (13.6)

Gamma Energy (probability)keV (%)

Radio nuclide Half life


…… future work

• To check the specific activities calculated by PACTITER by repeating CORELE experiments simulation and calculating the resin activities accordingly (Task TW4-TSS-SEA 5.5)

• Simulate the scheduled CORELE test at T=200 °C to estimate the duration required to get activity level into resins of main radionuclides (Mn-54, Co-60, Co-58) (Task TW5-TSS-SEA 5.5 D8)

• To simulate, in case, a new irradiation in OSIRIS reactor if that would be retained necessary (Task TW5-TSS-SEA4.1)

Documents

G. Cambi, D.G. Cepraga, M. Frisoni Presented by L. Di Pace (ENEA C.R. Frascati)