Impact on the IFMIF irradiation property from the beam profile

Transcription

1 Impact on the IFMIF irradiation property from the beam profile K. Kondo, U. Fischer, D. Große, A. Serikov KIT University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association

2 What is IFMIF? IFMIF (International Fusion Materials Irradiation Facility) Accelerator-based intense neutron source (D-Li, 40 MeV, 250 ma) Subjecting candidate materials for fusion reactors to similar conditions expected to be experienced by a future power plant (DEMO) Accelerator (125 ma 2) Lithium Target Test Cell Source LEBT 140 ma D + RFQ MEBT Half Wave Resonator Superconducting Linac HEBT 100 kev 5 MeV MeV H M L RF Power System High (>20 dpa/y, 0.5 L) Medium (>1 dpa/y, 6 L) Low (<1 dpa/y, > 8 L) 2

3 What is IFMIF/EVEDA? IFMIF/EVEDA (The Engineering Validation and Engineering Design Activities) Conducted in the framework of the Broader Approach (BA) Agreement between EU (F4E) and Japan (JAEA) Validation Activities: prototype accelerator (LIPAc) in Rokkasho, EVEDA Lithium Test Loop (ELTL) in Oarai Engineering Design Activities (EDA): Detailed, complete and fully integrated engineering design 3

4 What is LIPAc? Deuteron source 140 ma, 100 kev RFQ 5 MeV SRF Linac 40 MeV (Half Wave Resonators) Lithium Target 25 mm thick, 15 m/s High >20 dpa/an, 0.5 L Medium > 1 dpa/an, 6 L Low < 1 dpa/an, > 8 L Test Cell 2 accelerators, 2 x 125 ma, 2 x 5MW H M L Beam shape 200 x 50 mm 2 LIPAc = prototype for IFMIF includes all critical accelerator components to be tested at nominal beam current at BA site Typical reactions 7 Li(d,2n) 7 Be 6 Li(d,n) 7 Be 6 Li(n,T) 4 He Alban Mosnier, LIPAc overview, IFMIF/EVEDA Workshop #4 4

5 IFMIF-related activities in KIT/INR/NK group PA TF04 Other Engineering Validation Activities, Sub-activity TF04.6 on Engineering Design and Validation Activities on Neutronics Simulation Tools, Models and Data Development of McDeLicious Monte Carlo code to simulate d+li nuclear reactions as the neutron and photon source. Generation of the up-to-date neutronics geometry model by using McCad software and calculation of nuclear responses for the Test Facility, for which KIT is responsible. Provision of nuclear data above 20 MeV neutron energy collaborating with FENDL-3 activities by IAEA. PA ED04 Design Activity I, Test Cell (TC), Access Cell (AC), and Test Module Handling Cells (TMHCs) Neutronic analyses supports for the HEBT section layout design 5

6 IFMIF users requirements DPA 0.1 L > 50 dpa/fpy, 0.5 L > 20 dpa/fpy in High Flux Test Module (HFTM) The highest-value regions can be characterized as providing a damage production rate of 50 dpa/y in an irradiation volume of 0.1 liter and 20 dpa/y in a volume of 0.5 liter. Neutron flux gradients Less than 10%/cm Neutron flux gradient no greater than 10% across the gage volume of specimens, since a high flux dependence is known (e.g., the fracture toughness in the low fluence range) He-production/DPA, H-production/DPA The ratios of the transmutation reaction H- and He-production rates to the displacement rate in the specimens are required to be similar to those for the materials in service in the blanket structure of the fusion reactor. Affect swelling characteristics Ref: IFMIF Comprehensive Design Report (CDR), IFMIF International Team, Dec

7 Calculation model (Test Modules) HFTM CFTM Liquid Lithium Moderator (Tungsten) TRTM D beam LFTM Graphite 1m 7

8 Calculation model for HFTM-V (vertical cut) HFTM Lithium Target Specimen (Eurofer & NaK filling) Beam level Eurofer: NaK = 74:26 (volume ratio) Na:K = 22:78 (wt ratio) 8

9 Calculation model for HFTM-V (from front) Specimen (Eurofer & NaK filling) Heater (Eurofer & NiCr) Beam level 8.2 cm Beam footprint (200 mm x 50 mm) Eurofer: NaK = 74:26 (volume ratio) Na:K = 22:78 (wt ratio) 9

10 Calculation model for MFTM and LFTM (horizontal cut) Specimens of CFTM HFTM Lithium Target TRTM d-beam Graphite W moderator MFTM LFTM 10

11 McDeLicious Monte Carlo Code Developed at FZK/KIT to enable a proper representation of the d-li neutron and gamma source term in Monte Carlo transport calculations for IFMIF Enhancement to MCNP5 with tabulated double-differential d + 6,7 Li cross-section data up to 50 MeV Modeling of deuteron beam configuration, orientation and profile, Simulation of deuteron slowing down in Lithium MPI parallel calculation is available McDeLicious-05 (2005) : updated d + 6,7 Li evaluation McDeLicious-10 (2010) : Inclusion of primary photons McDeLicious-11 (2011) : New beam footprint implementation (with MCNP5-1.60) 11

12 Beam spatial profile d-beam #1 (40 MeV, 125 ma) d-beam #2 (40 MeV, 125 ma) 50 mm Li Jet Nuclear interaction simulated by McDeLicious Deuteron slowing down and neutron generation Back Plate y (EF, d = 7.8 g/cm 3 ) Neutron transport and nuclear responses Reflector Target (d = d norm ) (Li, d = 0.51 g/cm 3 ) HFTM (EF, d = 0.8 d norm ) 10 o 10 o Li(d,xn) d n n n n 1 R Li(n,x 3 H) p beam direction Li(d,x d 3 H) 0 n z 2 n 3 d Li(d,x 7 Be) R Reflector/MFTM p d n (d = 0.8 d Li(d,x ) 1 norm ) d Range 50 mm 20 mm Reflector (d = d norm ) 25 mm 1.8 mm 12

13 Yield(0 o ), /sr/ C d2 /d /de [mb/sr MeV] Yield(4 ), / C McDeLicious Monte Carlo Code 10 1 Total ( = 4 ) n-yield -yield Ed = 40 MeV Exp.: M.Hagiwara et al. Fus.Sci.Tech.48(2005)1320 McDeLicious MCNPX 10 2 Li(d,xn), E d =40 MeV Forward ( = 0 o ) - Daruga - Weaver n-yield - Goland - Amols - Nelson - Lone - Salmarsh - Johnson - Sugimoto - Bem - Baba M c DeLicious MCNPX -yield Deuteron Energy, MeV Baba, 03 evaporation preequilibrium stripping 1 level 2 level 3 level 4 level 5 level total Emitted neutron energy [MeV] 13

14 Relative strength (a.u.) Vertical axis (cm) Implementation of footprint data P.A.Phi Nghiem, HEBT-IFMIF-v output Previous (1999) Present (2011) Horizontal axis (cm) Previous (1999) Present (2011) Relative strength (a.u.) The beam distribution has been expressed by the sum of three Gaussian distribution functions in each direction. A new feature is implemented to sample the beam entry position according to a probability table 14

15 Beam dynamics calculation result x(mm) x'(mrad) y(mm) y'(mrad) z(mm) z'(mrad) Phase(deg) Time(s) Energy(MeV) Pow er(w,q=1) e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e+001 x, e+000 x, y, e+000 y, z, e-001 z, Phase, e e-001 Time, e+000 Energy, e e+001 Power e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e+001 for e+000 1e e+001 particles e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e+000 Only e-001 x and e+001 y e+000 were e+001 used e+000 in our e+001 calculation e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e

16 New footprint (probability table) The probability table was directly prepared by binning the distribution on the target obtained from the beam dynamics calculation in step of 5 mm for vertical and 10 mm for horizontal Vertical axis (mm) Horizontal axis (mm) 65 16

17 New footprint (probability table, smoothed and symmetrized) The table was smoothed with a Gaussian filter and averaged as it is symmetric with respect to both axes. 7.00E E E E E E E E Vertical axis (mm) Horizontal axis (mm)

18 Relative strength (a.u.) Vertical axis (cm) Previous footprint Previous (1999) Relative strength (a.u.) Previous (1999) Horizontal axis (cm) 18

19 Relative strength (a.u.) Vertical axis (cm) New footprint (fitting function sampling) Present (2011) Relative strength (a.u.) Present (2011) Horizontal axis (cm) 19

20 New footprint (table sampling) 20

21 DPA distribution inside HFTM (horizontal cut) Previous New DPA (/fpy) 21

22 DPA distribution inside HFTM (vertical cut) Previous New DPA (/fpy) 22

23 Available volume (cc) Available Volume in HFTM vs DPA Max cc = cm Present (2011) Previous (1999) cc > 50 dpa/fpy 500 cc > 20 dpa/fpy DPA (/fpy) 23

24 Neutron flux gradient inside HFTM Previous %-80% 60%-70% 50%-60% 40%-50% 30%-40% 20%-30% 10%-20% 0%-10% New (Table sampling) %-80% 60%-70% 50%-60% 40%-50% 30%-40% 20%-30% 10%-20% 0%-10% 24

25 Neutron flux gradient inside HFTM Previous %-80% 60%-70% 50%-60% 40%-50% 30%-40% 20%-30% 10%-20% 0%-10% New (Gaussian function) %-80% 60%-70% 50%-60% 40%-50% 30%-40% 20%-30% 10%-20% 0%-10% 25

26 DPA (/fpy) Row: DPA in each specimen stack of HFTM : Column Column no. row 1 row 2 row DPA (/fpy) 26

27 He/dpa in each specimen stack of HFTM Previous New

28 Effect from beam incident angle 8 deg. 13 deg DPA (/fpy) 28

29 Summary McDeLicious was updated to simulate the beam footprint according to a probability table. The impact on the nuclear responses from the difference of the beam footprint has been examined. DPA Neutron flux gradient He/DPA, H/DPA The previous manner in McDeLicious to describe the beam footprint using by combination of Gaussian functions would be not sufficient to asses above parameters. The impact on the nuclear responses from the difference of the beam incident angle is not signifficant. 29

30 Vielen Dank für Ihre Aufmerksamkeit! Thank you for your attention. ご静聴ありがとうございました 30

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32 4th proposal for HEBT section Now we assume the 4th proposal (July 2011) 1 kw loss on each Al scraper in RIR is assumed, where around 1e13 neutron production per sec. takes place. scrapers (Al) 1.5 kw kw loss on each scrapers (Al) 1 kw loss on each H: mm V: mm circular 200 mm H: mm V: mm K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

33 19.0 m Calculation model for building Scrapers Scrapers Bending magnet 1.2 m 2.5 m 2.8 m From DTL BTR RIR TIR TTC Local shield (Polyethylene) 5.7 m 7.0 m 20.5 m Li target 4.5 m 3.5 m 1.5 m K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

34 Layout of HEBT section (1) A beam scraper is needed to be installed in TIR or RIR. There has been iterative examination of the window size in the walls and the place of the beam scraper. Case 1 (11/2010) Case 2 (03/2011) Case 3 (06/2011) Case 4 (07/2011) Dia (mm) Dia (mm) Dia (mm) Dia (mm) Start End BTR-RIR (circular) RIR-TIR H V TIR-TTC H V Scraper TIR (1e-3) RIR (1e-3) RIR (1e-4) RIR (1e-3/1e-4) RIR TIR TTC RIR TIR TTC K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

35 Example of neutron flux distribution Case 1 Case 2 Scraper Scraper RIR TIR RIR TIR 10 9 Only streaming neutron (no scraper contribution) Neutron flux (/cm 2 /s) K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

36 Scraper contribution Neutron / photon production due to the d-al reaction 1 kw loss leads to around 1e13 (/s) neutron production! Physical models implemented in MCNPX INCL4/ABLA, ISABEL/ABLA The limit of these models has been pointed out by F. Ogando (UNED). (See his presentation) Neutron source term based on Hagiwara s experimental data Total neutron yield was multiplied by a factor of 2 considering ambiguity about the absolute values. Photon data is not available. Local shielding structure made of low density polyethylene (50 cm-t) is utilized around the scrappers K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

37 Neutron flux due to streaming RIR TIR Neutron flux (/cm 2 /s) K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

38 Neutron flux due to RIR scraper RIR TIR Neutron flux (/cm 2 /s) K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

39 Averaged neutron flux for beam ducts due to streaming 1.7E6 1.1E6 3.8E8 1.7E9 8.1E9 1.8E cm below beam duct 1.4E8 (average) 10 2 Neutron flux (/cm 2 /s) K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

40 Shutdown calculation condition Shutdown dose rate calculation FISPACT EAF months continuous operation in full power Contact dose rate at the surface of a semi-infinite slab (except d-scraper) Focusing on maintenance period (i.e. up to 10 3 days cooling) Beam ducts Al 5083 with the thickness of 5mm for all ducts 5 mm gap between the window in the concrete wall K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

41 Contact dose rate (Sv/h) Shutdown dose for beam duct in TIR (most downstream point, cell20003 seg1) 1.0E Na f n = (streaming) 1.0E Co (<- 58 Ni) 56 Mn (<- 56 Fe) 1.0E Mn(<- 54 Fe) 1.0E E-03 SS316L pure Ti Al 5083 Al 6063 Al 5083: 1.0 wt% Mn Al 6063: 0.1 wt% Mn 1.0E Cooling time (day) 54 Mn(<- 55 Mn) K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal

42 Contact dose rate (Sv/h) Shutdown dose for TIR (outside beam duct, averaged over r>50) 1.0E+01 f n = (streaming) 1.0E E E Mn (<- 55 Mn) SS316L Al E Co (<- 59 Co) 1.0E Cooling time (day) K.Kondo: TIR & RIR dose analysis for 4th HEBT proposal