Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Association FZK-Euratom Neutronic...

Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft Association FZK-Euratom

Neutronic Requirements for Fusion Relevant Reactor Material Irradiations

Nuclear Physics & Astrophysics at CERN NuPAC Meeting, 10-12 October 2005

Ulrich Fischer

Association FZK-EURATOMForschungszentrum Karlsruhe

Germany


U. Fischer, Neutronic Requirements for Fusion Reactor Material Irradiations - NuPAC Meeting, CERN, 10-12 October 2005

Outline

• Background

• IFMIF Intense Neutron Source

• Neutronics Tools & Data

• Design Analyses

• Conclusions



High Flux Components in Fusion Reactors

• Materials have to withstand high irradiation, heat and mechanical loads during reactor operation.

• Elemental transmutation and activation under irradiation – deteriorate the material properties – lead to a radiation hazard potential

Need for testing and qualifying materials under fusion-specific irradiation conditions



• Dedicated to material test irradiations at fusion-specific conditions (Demo/Power reactor)

– high neutron flux ( 1015 cm-2 s-1) and material damage accumulation ( 150 dpa in few years)

– suitable simulation of fusion neutron spectrum– sufficiently large irradiation volume

• Available irradiation facilities fulfil needs only partially

– fission reactors: large irradiation volumes & appropriate neutron flux but neutron spectrum not adequate

– accelerators (p, a, ..): appropriate dpa & gas production rates, favourable conditions for in-situ test but small volumes

– (d,t) neutron generators: proper fusion neutron spectrum but source intensity limited to 1013 s-1 (max. flux 1010 cm-2 s-1 )

Need for an Intense Neutron Source (INS)



• Limited testing in ITER

– fluence accumulation low ( 0.3 MWa/m2 3 dpa in iron)– operation mode very different from a Demo/power reactor

• pulsed operation (pulse length 1000 s)• low temperature operation

• No irradiation facility available with combined capabilities for

– simulation of fusion neutron spectrum – high fluence irradiation for accelerated material testing – sufficiently large irradiation test volumes

Need for an Intense Neutron Source (INS)



User Requirements for an INS

• Neutron flux/volume relation – Equivalent to 2MW/m2 in 10 L volume [1MW/m2 4.4·1013 n/cm2s; E = 14 MeV; 3x10-

7 dpa/s for Fe]

• Neutron spectrum– Should meet FW neutron spectrum as near as possible Quantitative

criteria: - Primary recoil spectrum, PKA - Important transmutation reactions: He, H.

• Neutron fluence accumulation:

– Demo-relevant fluences of 150 dpaNRT in few years

• Neutron flux gradient: 10 %/cm • Machine availability: 70 %• Time structure: Quasi continuous operation• Good accessibility of irradiation volume for experimentation and

instrumentation

1 MWa/m2 10 dpaNRT for Fe

IEA Workshop, San Diego, 1989



INS IFMIF• IEA workshops 1989- 1994

– San Diego 1989: review of INS concepts, evaluation of their suitability and feasibility, definition of key requirements, recommendation for viable INS options

– Karlsruhe 1992: consensus on accelerator based D-Li source

– Karlsruhe 1994: project planning

• Implementing agreement of IEA on IFMIF project:– Conceptual Design Activity (CDA), 1995 - 1996

– Conceptual Design Evaluation (CDE), 1997 - 1999

– Key Element Technology Phase (KEP), 2000 - 2002

– Transition Phase, 2003-2005 (?)

• Engineering Validation, Engineering Design Activity (EVEDA), 2006 – (?)



Test Cell

PIE Facilities

Access cell

IFMIF Intense Neutron Source

0 20 40m



IFMIF Design Concept

• Deuteron beams:– 2 x 125 mA– Ed = 40 MeV

• Neutron production:

1.1 1017 s -1

• Test volumes:– high flux: 0.5 L > 20 dpa/fpy(*)

– medium flux: 6 L > 1 dpa/fpy,– low flux: 7.5 L 0.1-1 dpa/fpy

Beam Spot(20x5cm2)

High Flux

Low FluxMedium Flux

LiquidLi Jet

DeuteronBeam

(*)fpy = full power year



Prove IFMIF’s suitability as neutron source for fusion-specific simulation irradiations

Provide reliable data for the technical layout of facility

• Computational tools and data required– D-Li neutron source term simulation– Neutron transport (En> 20 MeV) – Activation and transmutation (En> 20 MeV)

Key role in establishing IFMIF as neutron source for fusion material testing:

Need for experimental data, need for validation

IFMIF Neutronics



• D(Li,xn) source modelling

– MCNP McDeLi (semi-empirical reaction models) – McDeLi McDeLicious (evaluated d + 6,7Li data)

• Neutron transport

– MCNP/ McDeLi/ McDeLicious– Neutron cross-section data (ENDF6) E 20 MeV

• INPE Obninsk/FZK co-operation • HE data files (LANL, NRG, JENDL-HE)

• Activation & transmutation

– Intermediate Energy Activation File IEAF-2001– ALARA activation code (P. Wilson, Univ. of Wisconsin)

IFMIF Neutronics Tools & Data



Thick Li-target neutron yields

0 10 20 30 40

100

101

102

Deuteron Energy [MeV]

MCNPX

McDeLicious

McDeLi

Total Yield ( = 4)

Lone Johnson Sugimoto Mann Baba 2002

Neut

ron

Yiel

d,

1010

/C

0 10 20 30 4010-1

100

101 MCNPX

McDeLicious

Forward Yield ( = 0o)

McDeLi

- Daruga - Weaver - Goland - Amols - Nelson - Lone - Salmarsh - Johnson - Sugimoto - Bem 2002 - Baba 2002

Yiel

d,

1010

/sr/C


Total (4π) Neutron Yields Forward (0o) Neutron Yields



10-5

10-4

10-3

10-2

10-1

100

0 10 20 30 40

=0o

Neutr

on Y

ield

[1010 n

/sr/

MeV

/C]

Baba et al. 2002 McDeLicious MCNPX

0 10 20 30 40

Ed = 25 MeV

=20o =10o

0 10 20 30 40

Neutron energy [MeV]

0 10 20 30 40 50

=90o

0 10 20 30 40 50

0 10 20 30 4010-6

10-5

10-4

10-3

10-2

10-1

=60o =40o

D-Li thick target neutron yield spectra

Ed= 25 MeV



10-4

10-3

10-2

10-1

100

1010 10 20 30 40 50

=20o

=0o

Neutr

on Y

ield

[1010 n

/sr/

MeV

/C]

Baba et al. McDeLicious MCNPX

=10o

0 10 20 30 40 50

Ed = 40 MeV

0 10 20 30 40 50 60

=45o

0 10 20 30 40 5010-5

10-4

10-3

10-2

10-1 =60o

0 10 20 30 40 50


0 10 20 30 40 50 60

=90o

D-Li thick target neutron yield spectra

Ed= 40 MeV



Li(d,xn) Double Differential Cross Sections

0 5 10 15 20 25 30 35

10-1

100

101

102

Bem et al.

MCDeLicious

Li(d,xn), Ed = 16.6 MeV

= 0o

d2 /d

/dE

, m

b/sr

/MeV

Neutron Energy, MeV

0 10 20 30 40 50 6010-1

100

101

102

= 0o

Li(d,xn), Ed = 40 MeV

MCDeLicious

Neutron Energy, MeV

d2

/d/

dE,

mb/

sr/M

eV

Baba et al.

Ed = 17 MeV, Bem et al.

Ed = 40 MeV, Baba et al.



New d + Li Data Evaluation

0 5 10 15 20 25 30 3510-3

10-2

10-1

100

101

102

Bem, 03 Bem, 03 evaporation prequilibrium stripping 1 level 2 level 3 level 4 level 5 level total

7Li(d,xn), Ed=16.6 MeV

d2

/d/

dE

[m

b/s

r M

eV

]

Emitted neutron energy [MeV]

P. Pereslavtsev et al, FZK 2005



Thick Li-target neutron yields using 2005 D-Li data evaluation (P. Pereslavstev et al.)

0 10 20 30 4010-1

100

101

2001

MCNPX

McDeLicious

Forward Yield ( = 0o)

McDeLi

- Daruga 68 - Weaver 72 - Goland 75 - Amols 76 - Nelson 77 - Lone 77 - Salmarsh 77 - Johnson 79 - Sugimoto 95 - Bem 02 - Baba 01/02

Neu

tron

Yie

ld, 1010

/sr/C


2005



IFMIF Test Cell Calculations

• Major neutronics task in this context:– Provide the data required for the design and optimisation of

the irradiation test modules and the lay-out of the test cell

Neutron/photon transport calculations (McDeLicious) for flux distributions and nuclear responses such as nuclear heating, radiation damage accumulation and gas production.

• IFMIF’ s primary mission is to generate a materials irradiation database for the design, construction, licensing and operation of DEMO



Materials for IFMIF

• Highest priority: structural materials of the reduced activation ferritic-martensitic (RAFM) type (Eurofer, F82H). A variety of Eurofer specimens will be irradiated in the high flux test module

(HFTM) up to the target fluence of 150 dpa.

• Other materials of (possibly) lower priority:– SiC, V/V-alloy, divertor materials (e. g. W)– Breeder materials, neutron multiplier– Ceramic insulators and others



Element Specification [w%]

Element Specification [w%]

C 0.090-0120 W 1.0-1.2 Mn 0.20-0.60 Ti <0.01 P <0.005 Cu <0.005 S <0.005 Nb <0.001 Si <0.05 Al <0.01 Ni <0.005 N 0.015-0.045 Cr 8.50-9.50 B <0.001 Mo <0.005 Co <0.005 V 0.15-0.25 O <0.01 Ta 0.05-0.09 Fe balance

Chemical Composition of RAFM Steel Eurofer



• IFMIF project (INPE Obninsk/FZK)- 1H, 56Fe, 23Na, 39K, 28Si, 12C, 52Cr, 51V (50 MeV)

- 6,7Li, 9Be (150 MeV)

• LANL 150 MeV data files (ENDF/B-VI.6)- 1,2H, 12C, 16O, 14N, 27Al, 28,29,30Si, 31P, 40Ca, 50,52,53,54Cr, 54,56,57,58Fe, 58,60,61,62,64Ni, 63,65Cu, 93Nb, 182,183,184,186 W, 196,198, 199, 200, 201, 202, 204 Hg, 206, 20, 208 Pb, 209Bi

• NRG evaluations– 40,42-44,46,48Ca- 45Sc, 46-50Ti, 54,56-,58Fe, 70,72-74,76Ge, 204,206-208Pb, 209Bi

• JENDL-HE data file– 1H, 12,13C, 14N, 16O, 24-26Mg, 27Al, 28-30Si, 39,41K, 40,42- 46,48Ca, 46-50Ti,51V, 50,52-54Cr, 55Mn, 54,56-58Fe, 59Co, 58,60-62,64Ni, 63,65Cu, 64,66-68,70Zn,90- 92,94,96Zr, 93Nb,

180,182-184,186W, 196,198-202,204Hg

Neutron Cross-Sections E 20 MeV - General purpose data ENDF evaluations -



Iron Transmission Benchmark Experiment (Shin et al.)

0 10 20 30 40 50 6010-14

10-13

10-12

10-11

10-10

Shin et al. 91 MCNP/INPE-FZK MCNP/LANL-150

t = 50 cm

t = 40 cm

Neu

tron

Flu

ence

, n/c

m2 /M

eV/p

roto

n

Neutron Energy, MeV

t = 20 cm

10 20 30 40 501

2

3

4

5

Cierjacks 66 Perey 72 Larson 81 Abfalterer 2001 FZK/INPE LANL-150

To

tal n

eu

tro

n c

ross-s

ecti

on

[b

]

Neutron Energy, MeV

Fe slabs (20, 40 50 cm) irradiated with source neutrons produced by 65 MeV protons on Cu target

Fe(nat) total neutron cross-section



Li target

Irradiation test modules

IFMIF Test Cell

MCNP model (visualised by

CATIA)

CAD model (CATIA)

Beam lines



HFTM container

IFMIF High Flux Test Module (HFTM)

HFTM test rig

vertical cut horizontal cut



Distributions of nuclear responses in the HFTM

Displacement damage rate [dpa / fpy]

50

40

30

20

10

50

40

30

20

10

50

40

30

20

10

7 6 5 4 3 2 1 1Z

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9 10 11 12

1

2

3

4

52-Beams Footprint 20 x 5 cm2

dpa-rate [1/fpy]Y

Y

X

Z

d-Beams

Beam Footprint

7

6

5

4

3

2

1

X

Z

2420

16

12

8

24

20

16

12

8 4

24

20

16

12

8

7 6 5 4 3 2 1 1

2-Beams, Footprint 20 x 5 cm2

Z

0 1 2 3 4 5 6 7 8 9 10 11 12

1

2

3

4

5Nuclear Heating [W/cm3]

Y

Y

X

Z

d-Beams

Beam Footprint

7

6

5

4

3

2

1

X

Z

Nuclear heating [ W/ cm3]

McDeLicious calculations with simplified geometry model



-4

-3

-2

-1

0

1

2

3

4

0 10 20 30 40 50

dpa/fpy

Ver

tica

l D

irec

tion

, cm

Fe displacement damage

-4

-3

-2

-1

0

1

2

3

4

0 1 2 3

W/g

Ver

tica

l D

irec

tion

, cm

Nuclear heating

d - beam

Li – jet

HF

TM

(rig matrix)

HFTM

Distributions of nuclear responses in HFTM test rigs

McDeLicious calculations with detailed 3D geometry model

Nuclear heating

Displacement damage



Irradiation Parameters

Irradiation parameter IFMIF HFTM ITER DEMO

Total neutron flux [cm-2s-1] 1014 - 1015 4x1014 7.1x1014 Neutron flux, E > 14 MeV [cm-2s-1] 4x1013 - 2x1014 0 0 Hydrogen production [appm/FPY] 1000 – 2500 445 780 Helium production [appm/FPY] 250 – 600 114 198 Displacement production [DPA/FPY] 15 – 60 10 19 H/DPA ratio [appm/DPA] 35 – 50 44.5 41 He/DPA ratio [appm/DPA] 9.5 - 12.5 11.4 10.4 Wall load [MW/m2] 3 – 8 1.0 2.2

NB. Dpa and gas production data refer to iron.



Damage and gas production

• Displacement damage and elemental transmutations primary responses of the materials under neutron irradiation

• Displacement damage induced by incident neutron through transfer of kinetic energy to colliding nucleus– “primary knock-on atom” (PKA) displaced from lattice site– PKA can initiate further atom displacements in a sequence of succeeding

collisions (“collision cascades”)– quantification of displacement damage by calculation of number of

displacements per atom (dpa)

• Generation of gaseous transmutation products such as hydrogen (H) and helium (He) affects material irradiation behaviour (e. g. embrittlement and swelling)

Production ratios He/dpa and H/dpa primary parameters to characterise the suitability as fusion reactor material irradiation facility



Damage and Gas Production



PKA spectra

103

104

105

106

10-8

10-7

10-6

10-5

10-4

10-3

10-2

IFMIF High Flux Test Module Fusion Demo Reactor(HCPB) Fast Reactor (Phenix) High Flux Fission Reactor (Petten)

d/d

T [

ba

rn/e

V]

PKA energy

56Fe



Damage energy transfer function

10-3

10-2

10-1

100

0,0

0,2

0,4

0,6

0,8

1,0

56Fe

MFTM (bare) MFTM W plates MFTM W+C mod./refl. HFTM (bare) Demo fusion reactor

W(T

)

PKA Energy T [MeV]



• Intermediate Energy Activation File IEAF-2001 (FZK/INPE)

– Complete cross-section data library for activation and transmutation analyses up to En 150 MeV (1 Z 84)

– Validated through series of benchmark calculations, tested and qualified for SS-316 & V/V-alloy samples in IFMIF activation experiment

• ALARA activation code (P. Wilson, UW) – Analytical and Laplacian Adaptive Radioactivity Analysis– Capable of handling an arbitrary number of reaction channels

EAF-2005 (En 60 MeV) for FISPACT inventory calculations recently became available (UKAEA Culham)

Activation and Transmutation Analyses

Tools and Data



10-3 10-2 10-1 100 101 102 103 104 105 10610-6

10-4

10-2

100

102

104

106

W

LFTM

UTM

106ySS-316 & W, 1 year in IFMIF

TRM

BP

Hands-on Limit

Recycling Limit

104y100y1y30d1d

HFTM

Front Wall Liner

Con

tact

-Dos

e R

ate,

S

v/h

Time after shutdown, years

Induced radioactivity in the IFMIF HFTM components

Contact - dose rate after IFMIF full power irradiation

[Sv/h]

IFMIF HTFM components (CAD model)



IFMIF vs. FPR: Activation AnalysisEurofer Activity Eurofer γ-dose rate

10-2 100 102 104 106 108 101010-7

10-5

10-3

10-1

101

103

105

Hands-on Limit

Recycling Limit

54Mn

56Mn

106y104y1m

- FW/Demo - HFTM/IFMIF

26Al

100y1y30d1d1h

94Nb

60Co

Total Dose Rate

Con

tact

R

ay D

ose

Rat

e,

Sv/h

Time after shutdown, hours10-2 100 102 104 106 108 1010107

109

1011

1013

1015 - FW/Demo - HFTM/IFMIF

106y104y1m

53Mn

100y1y30d1d1h

55Fe

3H

14C

Total Activity

Act

ivit

y,

Bq/

kg

Time after shutdown, hours

3H yield: IFMIF > Demo due to 56Fe(n,t), Ethr = 12 MeV

60Co yield: IFMIF < Demodue to 59Co(n,)60Co



NPI Activation Experiment on W/Eurofer

D2O Target (Ø30×26 mm2)

Activation Foils

1.7 mm 47 mm ≈ 700 cm

NeutronDetector

24

6

1012

0 5 10 15 20 25-5-4-3-2-1012345

Ep = 36.5 MeV, p-Flux [1/cm2]

D2O -depth/p-beam direction, mm

Hor

izon

tal

dire

cton

, mm

37 MeV protons

1 10 4010-2

10-1

100

Spectrum used Activation Caclution

D2O(p,xn), E

p = 37 MeV

Rez Experiment

Neutron Energy, MeV

MCNPX/LA-150

= 0o

Spe

ctra

l Y

ield

, 1

010 n

/sr/

MeV

/C

Hf-

17

9n

Hf-

18

0m

Hf-

18

1

Hf-

18

2m

Hf-

18

3

Ta-

18

2

Ta-

18

3

Ta-

18

4

Ta-

18

5

W-1

81

W-1

85

W-1

87

10-1

100

101

102

103

F82H (d-Li)EF-97

W#14 W#4

W#7

C/E

W Activation Products

C/E ratios of induced -activities

p-D2O neutron spectrum



Transmutation of Eurofer

B C N O Al Si P S Ti V Cr Mn Fe Co Ni Cu Nb Mo Ta W

-10

-5

0

5

10

15

20

25

30

B C N O Al Si P S Ti V Cr Mn Fe Co Ni Cu Nb Mo Ta W

Weight % => .001 .105 .03 .01 .01 .05 .005 .005 .01 .2 9 0.4 89 .005 .005 .005 .001 .005 .07 1.1

Burn-up

Generation

Tra

nsm

uta

ion

ra

te (

Nu

mb

ers

of

Ato

ms

Ch

an

gin

g),

%

/fp

y DEMO IFMIF



He production cross-section of Fe-nat up to 100 MeV



Priority Isotopes Available Data Evaluations

High 56Fe ENDF/B-VI.6, NRG, FZK/INPE (50), JENDL-HE 52Cr ENDF/B-VI.6, FZK/INPE (50), JENDL-HE 182,183, 184, 186W ENDF/B-VI.6, JENDL-HE 9Be FZK/INPE 6,7Li FZK/INPE 28Si ENDF/B-VI.6, FZK/INPE (50), JENDL-HE 12C ENDF/B-VI.6, FZK/INPE (50), JENDL-HE 16O ENDF/B-VI.6, FZK/INPE (50), JENDL-HE 23Na FZK/INPE (50), 39K FZK/INPE (50), JENDL-HE

Neutron Data E> 20 MeV Required for IFMIF Neutronics



Priority Isotopes Available Data Evaluations

Medium 54, 57,58Fe ENDF/B-VI.6, NRG, JENDL-HE 50, 53,54Cr ENDF/B-VI.6, JENDL-HE 29,30Si ENDF/B-VI.6, JENDL-HE 63, 65Cu ENDF/B-VI.6, JENDL-HE 1H ENDF/B-VI.6, JENDL-HE 181Ta - + many more

Low 46, 47,48,49Ti JENDL-HE + many more .

Neutron Data E> 20 MeV Required for IFMIF Neutronics



Conclusions

• Neutron flux level & fluences

• Radiation damage & activation characteristics

– He/dpa ratio

– PKA spectrum, damage production function W(T)

– Transmutation products

• Sufficient irradiation test volume

• IFMIF shown to be suitable INS

INS for testing and qualifying fusion materials must be suited to simulate fusion relevant irradiation characteristics:



Conclusions

• Suitable computational tools, data and models available for IFMIF neutronics and activation analyses – McDeLicious Monte Carlo code for Li(d,xn) neutron source

– Various general purpose intermediate/high energy data evaluations– Activation and transmutation data libraries (up to 150 MeV)

• General purpose (ENDF) data evaluations E> 20 MeV

– Need for full IFMIF data library (validated data evaluations) Cross-section measurements, benchmark experiments

• Activation/transmutation/gas production data

– Need for validation ( Benchmark experiments)

– Need for cross-section measurements



IFMIF neutron flux spectrum

0,01 0,1 1 10 100100

101

102

103

104

105

106

107

ITER first wall IFMIF high flux test module HFR Petten

N

eutr

on fl

ux d

ensi

ty [

1010 /

cm2 /

MeV/s]


Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Association FZK-Euratom Neutronic...

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