fusion material transmutation and activation analysis induced … · 2016-06-26 · i iea...

I

IEAInternational Workshop on Fusion Neutronics

September 5, 2002 - Dresden - Germany

Fusion Material Transmutation andActivation Analysis Induced by Fast

Neutronsa) Vitenea-IEF radiation transport libraryb) ANITA-IEAF Activation code package

D. G. CepragaENEA, FIS-MET, Bologna, Italy

G. CambiBologna University, Physics Dept., Bologna, Italy

M. FrisoniAthena s.a.s., Bologna, Italy

Presented by Dan Gabriel Cepraga

ID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany

Ex glorioso “Nucleare” labore sincera voluptas

Background

The Bologna group (ENEA & University) effort for the IFMIF facility

project during 2001-2002 is related to the setting up, production and

application of new computational tools and data libraries for shielding

analysis (deterministic approach) and activation calculations to

contribute to define and establish shielding design criteria and to

assess the radiological protection related to beam-on and beam-off

operational phases:

production of the new groupwise radiation transport library,“Vitenea-IEF”, extended over 20 MeV, for deterministic Sn codes;

production of the Anita-IEAF activation code package (code andlibraries) able to handle the numerous reaction channels forneutron energies over 20 MeV;

application of the computational tools for radiation transport,material activation calculations and dose rate evaluation invarious IFMIF test facility rooms and cells for beam-on andbeam-off operating phases to verify the compliance with themaximum allowable limit.

IID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


a) Vitenea-IEF radiation transport library

The “Vitenea-IEF” is a new intermediate energy coupled 256-neutron

and 49-gamma-ray multigroup cross-section library, in Ampx format,

suitable for Sn radiation transport codes.

The library was obtained by processing the LANL evaluated files

of ENDF/B-VI release 6 and FZK/INPE files via the Njoy-Smiler-

Ampx-Scale code systems.

The library contains the following materials/isotopes: H-1,H-2, C,

O-16, Al-27,Si-28,Si-29, Si-30, P-31, Ca, Cr-50, Cr-52, Cr-53, Cr-

54, Fe-54, Fe-56, Fe-57, Ni-58, Ni-60, Ni-61, Ni-62, Ni-62, Ni-

64,Cu-63, Cu-65, Nb-93, W-182, W-183, W-184, W-186, Pb-206,

Pb-207, Pb-208 from ENDF/B-VI Release 6 and K-39, Li-6, Li-7,

V-51 from FZK/INPE Nuclear Data.

The inclusion in the library of the ENDF/B-VI materials together with

FZK ones makes it possible to handle the most part of materials, as

lithium target, steel and concrete, planned to be used in IFMIF design.

IIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


The following choices in the Njoy processing (99.50 version) were

applied.

For neutrons:

• 256-group energy structure till 150 MeV (standard 175-groupVitamin-J structure until 19.64 MeV and 81 groups above;constant energy bins of 1 MeV and 2 MeV were used for the energydomains 20-50 MeV and 50-150 MeV, respectively);

• weighting function: thermal + 1/E + flat

• 4 temperatures: 300K, 600K, 900K, 1500K;

• 10 values of background cross sections: 1.0E+10, 1000, 300, 100,30, 10, 3, 1, 0.1, 1.0E-06

For gamma’s:

• 49-group energy structure till 100 MeV (standard 42-groupVitamin-J structure until 50 MeV and 7 groups above; constantenergy bins of 5 MeV and 10 MeV were used for the energydomains 50-70 MeV and 70-100 MeV, respectively);

• weighting function: flat over the entire energy range.

IVD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Remarks

• The production of the library required the development of a new

Smiler code, which converts the Njoy output from GENDF to

AMPX format, in collaboration with the ORNL group of the

Ampx-2000 system, in order to let it manage the not standard

ENDF format lumped MT=5 cross section structure contained in

the evaluated files for neutron energies over 20 MeV.

• In order to perform the dose rate calculations by Sn method, a new

file, containing the groupwise neutron and gamma fluence to

ambient dose equivalent conversion factors, was produced. It was

obtained by integrating the neutron and gamma pointwise factors

available in literature (ICRP-74 and Ferrari-Pelliccioni evaluation)

on the same weighting functions and group structures previously

described, converted in Ampx format and included in the Vitamin-

IEF library.

VD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


RECONRReconstruct pointwise

cross sections

RECONRReconstruct pointwise

cross sections

Neutrons

BROADR

UNRESR

GROUPR

GENDFGENDF

SMILER-IEF

RADE-PERFUME-AJAX

GAMINR

ENDF/B-VI release 6 & FZK/INPENuclear Data

Doppler treatment

Processing ofunresolved resonances

Multigroup photoninteraction data production

49-groupdata

256-groupdata

Multigroup neutrondata production

Photons

GENDF to AMPX format conversion(Cross sections over 20 MeV treatment - MT=5)

Check and assembling ofMaster AMPX library

VITENEA-IEFCoupled 256n-49gcross section library

Procedure for generating Vitenea-IEF Library

VID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


b) ANITA-IEAF activation code package

The new ANITA-IEAF activation code package traces back tothe ANITA-2000 code [2] . It is able to manage the manyreaction channels that open for neutron energies higher than20 MeV and up to 150 MeV.

It computes the radioactive inventories of materials exposed toneutron irradiation, continuous or stepwise. It providesactivity, isotope nuclide density, decay heat, biological hazard,clearance index and decay gamma ray sources, in the 42standard Vitamin-J energy structure, at shutdown and atdifferent cooling times.

The code package is provided with a complete data base thatincludes neutron activation data library, decay, hazard andclearance data library, and gamma library

VIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


.The new ANITA-IEAF activation code package is based on the Anita-

2000 code (NEA-1638, RSICC CCC-606).

256-groupneutron fluxes

fromradiation transport

calculation

Radioactiveinventories

Activity Decay HeatContact Dose Decay gamma source

Clearance index Biological Hazard

ANITA-IEAFneutron

activation library

UnconditionalClearance Level

Data Library

Decay and Hazarddata library

Decay gammalibrary

ANITA-IEAFActivation

code

VIIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


New Anita-IEAF activation library

• It has been derived by the FZK IEAF-2001 activation library.

• IEAF-2001 contains neutron activation cross sections for 679nuclides, in Gendf format, not suitable to be used in Anita code, inthe 256 neutron energy groups structure. In this library theneutron activation cross sections for each nuclide are identified inthe MF=3, MT=5 structure by the recoil nucleus produced. This isdue to the fact that for neutron energies greater than 20 MeV manyreaction channels open, to which don’t correspond well defined MTnumbers in the standard ENDF6 format notation.

IEAF-2001256-group data activation library

(GENDF format)

CONVLIBProduction of ANITA-IEAF activation library

in EAF groupwise format

ANITA-IEAFneutron activation library

679 nuclides, 96448 reactions256 energy groups

A fixed reaction table, as required in Anita code, is so created, byassociating to every recoil nucleus, characterized by a well knowndifference in charge Z and mass A, a, not standard, MT number.

IXD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Anita-IEAF Decay, Hazard and Clearance Data Library

This library contains the information describing the decay properties

of unstable nuclides useful for the calculations performed by ANITA-

IEAF. This file has been completely updated. It contains the following

data for 1840 nuclides:

• The decay data have been taken from the Fusion EvaluatedNuclear Decay Data Library FENDL/D-2.0.

• The Annual Limit of Intake (Bq) by ingestion or inhalation for thepublic or workers (ALI) quantities are obtained from the ICRP-72.

• The clearance level data. They are the “unconditional clearancelevels” (Bq/g), based on IAEA-TECDOC-855.

Anita-IEAF Gamma Library

This data base contains gamma ray spectra emitted by the radioactive

nuclei (1390 isotopes) in the Vitamin-J 42-γ energy group structure.

The data of the library are based on the FENDL/D-2 evaluated decay

data file (gamma radiation spectra).

XD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Application of ANITA-IEAF code package:

activation calculation for IFMIF Test Cell steel liner

The Sn radiation transport calculation sequence, via the Bonami S -

Nitawl II - Xsdrnpm modules of the Scale 4.4a system with the new

intermediate energy coupled 256n-49γ multigroup cross-section

library Vitenea-IEF was used to define the neutron flux spectra for

the activation calculations.

A total neutron source (due to the interaction of the primary 40 MeV

deuteron beam on the Li target) of 1.1 x 1017 s-1 was considered to

normalise the calculations.

A continuous 5 years irradiation has been applied.

XID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


The IFMIF Test Cell modelled in the calculations contains:

a. Lithium target,b. Back plate, c. High Flux Test Module-HFTM, d. Test Cell vacuum room, that encloses the test module and

the lithium target, e. Neutron and gamma concrete shielding system.

A test cell liner, constructed from stainless steel, is located between the

vacuum room and the shielding concrete wall. The thickness of the

liner has been chosen to be 20 mm.

XIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Specific activity and decay heat of the Test Cell steel liner

Cooling Activity Decay heattime [Bq/g] [W/g]zero 9.01E+8 7.67E-51 s 9.00E+8 7.66E-5

30 m 8.54E+8 6.09E-51 h 8.42E+8 5.70E-55 h 7.87E+8 4.10E-51 d 7.29E+8 3.20E-57 d 6.78E+8 2.93E-5

30 d 5.71E+8 2.43E-590 d 4.33E+8 1.61E-51 y 2.78E+8 5.11E-63 y 1.49E+8 1.56E-6

10 y 2.61E+7 3.44E-730 y 1.99E+6 2.77E-850 y 1.56E+6 5.90E-9100 y 1.10E+6 3.01E-9

1000 y 2.02E+4 4.56E-11

XIIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Isotope specific activity of the Test Cell steel liner at the end of beam-

on phase (IFMIF plant shut down)

Isotope Activity %[Bq/cm3]

Fe 55 2.32E+09 3.26E+01Cr 51 1.60E+09 2.24E+01Co 58 8.93E+08 1.25E+01Mn 56 5.91E+08 8.29E+00Co 57 3.86E+08 5.42E+00Co 58m1 3.81E+08 5.34E+00Mn 54 3.78E+08 5.30E+00V 52 1.20E+08 1.68E+00Cu 64 1.04E+08 1.46E+00V 49 4.21E+07 5.90E-01Al 28 2.97E+07 4.17E-01Ni 57 2.96E+07 4.15E-01Fe 59 2.68E+07 3.76E-01Co 60m1 2.40E+07 3.37E-01Co 60 2.23E+07 3.12E-01Mn 52m1 2.13E+07 2.99E-01Co 56 1.99E+07 2.78E-01Cu 66 1.89E+07 2.65E-01Ni 63 1.73E+07 2.42E-01Fe 53 1.63E+07 2.29E-01Cr 55 1.63E+07 2.28E-01Ni 65 1.44E+07 2.01E-01Mn 57 1.08E+07 1.52E-01V 53 9.19E+06 1.29E-01Cu 62 7.53E+06 1.06E-01Sum 7.10E+09Rest 3.41E+07Total 7.13E+09

XIVD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Isotope specific activity of the Test Cell steel liner during beam-off

phase (1 year cooling time)

Isotope Activity %[Bq/cm3]

Fe 55 1.80E+09 8.17E+01Mn 54 1.68E+08 7.62E+00Co 57 1.52E+08 6.90E+00Co 58 2.50E+07 1.13E+00V 49 1.95E+07 8.86E-01Co 60 1.95E+07 8.85E-01Ni 63 1.71E+07 7.77E-01Sum 2.20E+09Rest 1.24E+06Total 2.20E+09

XVD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Impact of the neutrons with energy higher than 20 MeV

The following index is consideredR = Awithout/Awith

where:

Awith = steel liner activities when all the neutrons taken into account

Awithout = steel liner activities when only the neutrons up to 20 MeV takeninto account

Ratio R vs. cooling time

0.6

0.7

0.8

0.9

1.0

0.00001 0.001 0.1 10 1000

Cooling time [y]

R

The steel liner activity results to be underestimated by about 20% upto 3 years from the end of beam-on operations if the higher energyneutrons are not considered.

XVID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


CONCLUSIONS

THE ANITA-IEAF IS A CODE PACKAGE ABLE TOPERFORM ACTIVATION CALCULATIONS FOR MATERIALSEXPOSED TO NEUTRONS WITH ENERGIES UP TO 150 MEV.

A NEW ANITA-IEAF ACTIVATION LIBRARY HAS BEENPRODUCED

A NEW NEUTRON AND GAMMA TRANSPORT LIBRARY(VITENEA-IEF) HAS BEEN PRODUCED

AN APPLICATION OF THE NEW TOOLS AND LIBRARIES TOTHE IFMIF TEST CELL STEEL LINER HAS BEENPERFORMED.

IT POINTED OUT THAT THE STEEL LINER SPECIFICACTIVITY IS UNDER-ESTIMATED BY ABOUT 20% UP TOFEW YEARS FROM THE END OF BEAM-ON OPERATIONSWHEN THE CONTRIBUTE OF INTERMEDIATE ENERGYNEUTRONS IS NOT TAKEN INTO ACCOUNT.

XVIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


MAIN REFERENCES

D.G. Cepraga, G. Cambi, M. Frisoni, G.C. Panini, Anita-2000 Code Package, IsotopeInventories from N irradiation, for Fusion Applications, NEA data Bank ProgramLibraries, NEA 1638, 22-November 2000.

U.Fischer, D.Leichtle, A.Konobeyev, Yu. Korovin, U.v.Mollendorf, P.Pereslavtsev,I.Schmuck, Intermediate Energy Activation File 2001 (IEAF-2001),Forschungszentrum Karlsruhe, Technik und Umwelt, Interner Bericht, IRS-Nr.10/01-FUSION-Nr. 179, August 2001; U.Fischer, D.Leichtle, U.v.Mollendorff andI.Schmuck, ZZ-IEAF-2001, Intermediate Energy Activation File, NEA-1656/01.

M. Frisoni, D.G. Cepraga, G. Cambi, New computational tools and data libraries forIFMIF shielding calculations, ENEA report FUS-TN-SA-SE-R-034, June 2002.

XVIIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


APPENDIX

Difficilis facilisIucundus acerbus es idemNec tecum possum vivereNec sine te

XIXD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


To study the irradiation effects on fusion materials somefacilities have been proposed to produce accelerator-basedneutron sources at sufficient intensity to test samples ofcandidate materials to be used in future fusion plants. In thesefacilities there is a considerable amount of neutrons producedwith energy above 20 MeV. One of the most important effectsof the neutron irradiation is the induced activation of thematerials. Nuclear activation data above 20 MeV are stillscarce and the existing available activation codes cannot treatthe numerous and “exotic” reaction channels that open atthese energies.

In the frame of the European Fusion Development Agreement(EFDA), the ENEA-Bologna team was committed to performshielding calculations of various Test Facility rooms and cellsfor the International Fusion Materials Irradiation Facility(IFMIF). That assessment required the setting up, productionand application of new computational tools and data librariesfor shielding analysis and activation calculations to contributein defining and establishing shielding design criteria related tobeam-on and beam-off operational phases. In particular, thepresence in IFMIF facility of a considerable amount ofneutrons produced at energies above 20 MeV implied theproduction of the ANITA-IEAF activation code package

XXD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


IFMIF TEST CELL GEOMETRICAL CONFIGURATION

To perform the neutron transport calculations via the onedimensional discrete ordinates code XSDRNPM ( TRANSACTmodular code system) the IFMIF Test Cell geometrical layout wasmodelled in order to maintain the real equivalent volumes of thevarious regions of the Test Cell (lithium target, back plate, HighFlux Test Module, Test Cell vacuum room, shielding walls etc.).This choice assures that the total volumetric collision densities arepreserved in the various zones.

The IFMIF Test Cell modelled in the calculations contains:(1)-Lithium target (24 cm*6 cm *3 cm ,volume=432 cm3 ),(2)- Backplate (24.1 cm*6.1 cm *3.1 cm), (3)- High Flux Test Module-HFTM (20 cm*5 cm *5 cm, volume=500 cm3), (4)- Test Cellvacuum room (300 cm* 250 cm * 300 cm) that encloses the testmodule and the lithium target, (5)- neutron and gamma concreteshielding system

A test cell liner, constructed from stainless steel, is locatedbetween the vacuum room and the shielding concrete wall. Thethickness of the liner has been chosen to be 20 mm. An heliumgap as active cooling is provided along the internal surface of theliner, in order to maintain the liner itself at a temperature less than50 0 C.

A concrete shielding, consisting of concrete 80%, plus He 20%for cooling, thickness 100cm, and concrete 100% up to a totalthickness of 310 cm, was placed after the test cell vacuum room.

XXID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Material compositions

The neutron and gamma transport calculations were performedby using the new intermediate energy coupled 256-neutron and 49gamma-ray multigroup cross-section library “Vitenea-IEF”, inAmpx format.

In order to use the materials/isotopes contained in the library thefollowing material compositions were chosen:• lithium target: lithium natural isotopic abundance.• back plate: stainless steel SS-316 LN-IG• High Flux Test Module : Eurofer. • liner and thermal shield: stainless steel SS-316 LN-IG• biological shield: concrete.

XXIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


SS 316 LN -IGDensity = 7.92 g/cm3

C 0.0225, Al 0.05, Si 0.5, P 0.025, V 0.004, Cr 17.5, Fe69.3375, Ni 12.25, Cu 0.3, Nb 0.01, W 0.001

SS 316 LN –IG (for activation calculation)Density = 7.92 g/cm3

C 0.0225, Al 0.05, Si 0.5, P 0.025, Ti 0.14, V 0.004, Cr17.5, Mn 1.8, Fe 64.8475, Co 0.05, Ni 12.25, Cu 0.3,Nb 0.01,Mo 2.5, W 0.001

EuroferDensity = 6.24g/cm3

C 0.105, O 0.01, Al 0.01, Si 0.05, P 0.005, V 0.2, Cr 9.526,Fe 88.983, Ni 0.005, Cu 0.005, Nb 0.001 W 1.1

LithiumDensity = 0.512 g/cm3

Li 100.0

Concrete Density = 2.32 g/cm3

H 0.555, O 49.748, Na 1.708, Al 4.691, Si 31.471, K 1.922,Ca 8.667, Fe 1.238

XXIIID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Neutron Source

In order to perform the coupled n-γ transport calculation an angle-and group-dependent boundary neutron source was used to takeinto account that the real neutron source is not isotropic, butpeaked in the forward direction

In this case, one specifies not a source but a flux condition on theboundary

The energetic neutron source distribution, due to the interaction ofthe primary 40 MeV deuteron beam on Li-target, calculated byOyama based on the Serber model has been produced in the same256 group structure of the Vitenea-IEF library.

A total neutron source of 1.1E+17 s-1 was used to normalise thecalculations.

XXIVD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


IFMIF energy source distribution for 40MeV deuteron beam

00.020.040.060.080.1

0.120.14

0 10 20 30 40

energy (MeV)

prob

abili

ty P

(E)

Figure 1 – Neutron energy source distribution for 40 MeV deuteron beam

XXVD.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


Total neutron fluxvs. distance from targetStandard configuration

Frontal wall case

1.E+00

1.E+02

1.E+04

1.E+06

1.E+08

1.E+10

1.E+12

1.E+14

1.E+16

0 200 400 600

Distance from target [cm]

Neu

tron

zone

-ave

rage

d to

tal

flux

[n/c

m2

s]

TOTAL ZONE NEUTRON FLUX (n/cm2×s)

Lithium Target Back Plate 1.27E+15HFTM 5.33E+14Liner 2.21E+12

XXVID.G.Cepraga, G.Cambi, M.Frisoni, IEA International Workshop on Fusion Neutronics, 5 September 2002 Dresden, Germany


fusion material transmutation and activation analysis induced … · 2016-06-26 · i iea...

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