HIGH-ENERGY MODELS FOR ACCELERATOR- DRIVEN SUB-CRITICAL REACTORS

Transcription

1 HIGH-ENERGY MODELS FOR ACCELERATOR- DRIVEN SUB-CRITICAL REACTORS Davide Mancusi CEA-Saclay, DEN/DANS/DM2S/SERMA EXTEND-2016, UPPSALA, SWEDEN 30 TH AUGUST 2016 Davide Mancusi EXTEND th August 2016 PAGE 1

2 OUTLINE introduction ADS in GEN-IV definitions, intense neutron flux production particle-matter interaction in ADS specific features of high energy reactions energy and target material choice residues some examples of targets for spallation neutron sources, accelerator-driven sub-critical systems, radioactive ion beams spallation reaction modelling basic assumptions the different models (INC and de-excitation) comparisons to elementary experimental data: neutrons, light charged particles, residues predictions of the simulation codes for applications Davide Mancusi EXTEND th August 2016 PAGE 2

3 ADS in GEN-IV definitions, intense neutron flux production INTRODUCTION Davide Mancusi EXTEND th August 2016 PAGE 3

4 WHAT IS AN ACCELERATOR-DRIVEN SUB-CRITICAL REACTOR? a spallation target which produces an intense neutron flux though high-energy reactions of protons with a high-z target surrounded by a sub-critical reactor driven by the external source in which transmutation of minor actinides is achieved Davide Mancusi EXTEND th August 2016 PAGE 4

5 OBJECTIVES OF GEN-IV NUCLEAR SYSTEMS sustainability provide sustainable energy generation that meets clean air objectives and promotes long-term availability of systems and effective fuel utilization for worldwide energy production minimize and manage their nuclear waste and notably reduce the long-term stewardship burden economics will have a clear life-cycle cost advantage over other energy sources will have a level of financial risk comparable to other energy projects safety and reliability will excel in safety and reliability will have a very low likelihood and degree of reactor core damage will eliminate the need for offsite emergency response proliferation resistance and physical protection will increase the assurance that they are a very unattractive and the least desirable route for diversion or theft of weapons-usable materials, and provide increased physical protection against acts of terrorism Davide Mancusi EXTEND th August 2016 PAGE 5

6 NUCLEAR WASTE MANAGEMENT two options to transmute minor actinides homogeneous multi-recycling small amount of MA in all reactors dedicated transmuters with high content of minor actinides in limited number degradation of safety parameters (βeff, Doppler coefficient, ) less problematic in ADS Davide Mancusi EXTEND th August 2016 PAGE 6

7 MINOR ACTINIDE TRANSMUTATION IN ADS From GEDEPEON Workshop on ADS May 18-19, 2006, Aix en Provence Davide Mancusi EXTEND th August 2016 PAGE 7

8 specific features of high energy reactions energy and target material choice residues PARTICLE-MATTER INTERACTION IN ADS Davide Mancusi EXTEND th August 2016 PAGE 8

9 SPALLATION REACTIONS definition interaction of a high energy (> 100 MeV) light particle with a nucleus leading to emission of light particles (mostly neutrons) and leaving a heavy residue history observation of particle cascades in cosmic rays interactions (Rossi, ZP82 (1933) 151) first accelerators: many nucleons emitted by the target nucleus (Cunningham, PR72 (1947) 739) two-step mechanism (Serber, PR72 (1947) 1114) Davide Mancusi EXTEND th August 2016 PAGE 9

10 ASTROPHYSICS secondary reactions of cosmic rays in interstellar medium (90% hydrogen) explanation of abundance of isotopes decide among models for galactic nucleosynthesis origin of cosmic rays composition of meteorites Davide Mancusi EXTEND th August 2016 PAGE 10

11 SPALLATION REACTIONS IN SPACE INSTRUMENTS cosmic ray bombardment of spacecraft and instruments radiation damage on electronics radioprotection of space crew noise due to secondary neutrons, gammas from spallation residues Davide Mancusi EXTEND th August 2016 PAGE 11

12 SPALLATION NEUTRON PRODUCTION in a heavy metal target (Pb, W, Ta, Pb-Bi) around 20 neutrons per incident proton and GeV applications: ADS spallation neutron sources rare isotope beams (RIB) in a thick target: internuclear cascade large number of produced neutrons Davide Mancusi EXTEND th August 2016 PAGE 12

13 SPALLATION NEUTRON SOURCES moderation of spallation neutrons in (heavy) water reflectors to direct escaping neutrons into beam tubes pulsed sources (ISIS, SNS, JSNS, ESS): well-defined time structure, high peak flux ToF experiments continuous sources (SINQ): high neutron flux in a large volume irradiation experiments, imaging Davide Mancusi EXTEND th August 2016 PAGE 13

14 SPALLATION SOURCES JPARC 3 GeV Davide Mancusi EXTEND th August 2016 PAGE 14

15 RARE ISOTOPE PRODUCTION direct methods ISOL p (1 GeV) + A low energy RIB fragmentation of GeV/A heavy ions high energy RIB converter methods use of produced neutrons to induce fission low energy RIB use of neutrons to produce tritium isotopes for medicine Davide Mancusi EXTEND th August 2016 PAGE 15

16 INTERACTIONS IN A THIN TARGET ~2 neutrons with E>20 MeV (intranuclear cascade) ~15 neutrons with E<20MeV (evaporation) but energy carried away by cascade neutrons = 85% 95% for protons Davide Mancusi EXTEND th August 2016 PAGE 16

17 INTERACTIONS IN A THICK TARGET L = 100 cm 1 GeV Pb R = 10 cm protons interact before slowing down 3.5 reactions per incident proton in average large number of secondary neutron interactions Davide Mancusi EXTEND th August 2016 PAGE 17

18 HEAT DEPOSITION IN A THICK TARGET MEGAPIE target: 600 MeV protons on Pb-Bi T. Kirchner, MEGAPIE workshop, 2002 Davide Mancusi EXTEND th August 2016 PAGE 18

19 DPA IN JNSN Power: 1MW (3 GeV, 0.33 ma) PBW: proton beam window (A5083, 2.5 mm x 2 plates) TV: target vessel (316L stainless steel) RV: reflector vessel (iron) Harada et al. J. of Nucl. Mater. 343 (2005) 197 Davide Mancusi EXTEND th August 2016 PAGE 19

20 DPA IN JNSN Harada et al. J. of Nucl. Mater. 343 (2005) 197 Davide Mancusi EXTEND th August 2016 PAGE 20

21 SPALLATION NEUTRON PRODUCTION in a heavy metal target (Pb, W, Ta, Pb-Bi) around 20 neutrons per incident proton and GeV maximum efficiency around 1 GeV Davide Mancusi EXTEND th August 2016 PAGE 21

22 CHOICE OF INCIDENT ENERGY Target length and diameter optimization maximize lateral low energy n minimize high-energy leaks F. Lavaud, SPhN report 1998 S. Leray, J. Phys. IV 9 (1999) 57 Davide Mancusi EXTEND th August 2016 PAGE 22

23 CHOICE OF MATERIAL neutron production increases with target thickness and saturates above 30 cm is similar for W to Pb for the same atom density choice of material from technological criteria Davide Mancusi EXTEND th August 2016 PAGE 23

24 THE CHOICE OF HG AS A TARGET W and Ta with 20 vol% D 2 O coolant calculated neutron leakage from a target of ESS geometry for different target materials calculated decay power for 200 days of operation in a 5 MW beam Y. Kadi, EURISOL week November 2006 Davide Mancusi EXTEND th August 2016 PAGE 24

25 CHOICE OF MATERIAL solid targets : W, Ta, depleted U spallation products confined no container simplicity limited power evacuation necessity of a coolant density of spallation material reduced irradiation damage (dpa, gas production...) can lead to embrittlement of the target liquid targets : Hg, Pb, Pb-Bi eutectic target = coolant high compactness volatile spallation products can be removed during operation no structural damage in target damage in window and container corrosion due to liquid metal highly activated circulating fluid ancillary heater necessary to keep Pb or LBE liquid Davide Mancusi EXTEND th August 2016 PAGE 25

26 HELIUM AND HYDROGEN PRODUCTION Comparison of several spallation sources Davide Mancusi EXTEND th August 2016 PAGE 26

27 RESIDUES PRODUCED IN P+PB REACTION AT 1 GEV hundreds of different residues produced Davide Mancusi EXTEND th August 2016 PAGE 27

28 INTERACTIONS IN A THICK TARGET 3.6 residues per incident protons on average highest mass residue coming mostly from low energy interactions Davide Mancusi EXTEND th August 2016 PAGE 28

29 ACTIVITY IN A THICK PB-BI TARGET (MEGAPIE) activity in the MEGAPIE target S. Lemaire et al., ND2007, Nice Davide Mancusi EXTEND th August 2016 PAGE 29

30 ACTIVITY IN A THICK PB-BI TARGET (MEGAPIE) activity from spallation and activation S. Lemaire et al., ND2007, Nice S. Lemaire et al., ND2007, Nice Davide Mancusi EXTEND th August 2016 PAGE 30

31 accelerator-driven system projects spallation neutron sources rare isotope production SOME EXAMPLES OF SPALLATION TARGETS Davide Mancusi EXTEND th August 2016 PAGE 31

32 MYRRHA SPALLATION LOOP target boundary conditions produce ~10 17 neutrons/s to feed subcritical keff 0.95 accept 600 MeV x 2.5 ma or 350 MeV x 5 ma proton beam evacuate deposited heat MW depending on beam choice erosion limit: v<2.5 m/s lifetime: > 1y Davide Mancusi EXTEND th August 2016 PAGE 32

33 JAPAN PROTON ACCELERATOR RESEARCH COMPLEX (J-PARC) Davide Mancusi EXTEND th August 2016 PAGE 33

34 JPARC TRANSMUTATION EXPERIMENTAL FACILITY Liquid lead-bismuth 600 MeV-200 kw proton beam n/cm 2 /s ADS Target Test Facility (TEF-T) Davide Mancusi EXTEND th August 2016 PAGE 34

35 ISIS SPALLATION NEUTRON SOURCE proton energy : 800 MeV proton current: 60 µa average power : 48 kw pulse rate : 10 Hz proton beam size : 1.5 cm FWHM target : tungsten (W) clad in tantalum (Ta) target coolant : D20 reflector : Beryllium reflector coolant : D20 Davide Mancusi EXTEND th August 2016 PAGE 35

36 SNS LIQUID MERCURY TARGET (2 MW) power absorbed in Hg: 1.1 MW temperature inlet to target : 60 ºC exit from target : 90 ºC Nominal operation pressure: 0.3 MPa flow rate: 340 kg/s vmax (in window): 3.5 m/s total Hg inventory: 1.4 m 3 pump power: 30 kw Davide Mancusi EXTEND th August 2016 PAGE 36

37 EURISOL REFERENCE MULTI MW TARGET STATION Hg converter and secondary fission targets Y. Kadi, EURISOL week November 2006 Davide Mancusi EXTEND th August 2016 PAGE 37

38 EURISOL TARGET B. Rapp, EURISOL meeting, March 2006 Davide Mancusi EXTEND th August 2016 PAGE 38

39 basic assumptions the different models (INC and de-excitation) comparisons to elementary experimental data: neutrons, light charged particles, residues predictions of the simulation codes for applications SPALLATION-REACTION MODELLING Davide Mancusi EXTEND th August 2016 PAGE 39

40 QUANTITIES RELATED TO SPALLATION REACTIONS neutron production number beam energy, accelerator intensity energy, spatial distribution target optimisation, damage in window and structures high energy neutrons shielding charged particle production gas (H 2, He) production embrittlement, swelling energy DPA, energy deposition residual nuclide production element distribution corrosion, change in material properties isotope distribution activity (short lived isotopes), radiotoxicity (long lived isotopes), decay heat, delayed neutrons recoil energies DPA in window and structures, energy deposition Davide Mancusi EXTEND th August 2016 PAGE 40

41 SIMULATION TOOLS FOR SPALLATION SOURCE DESIGN Monte-Carlo transport codes MCNPX, FLUKA, Geant4 propagation of all particles created in elementary interactions above (20) MeV nuclear physics models (intra-nuclear cascade (+ pre-eq) + evaporation-fission) cross-sections, properties of emitted particles directly used by the transport codes below (20) MeV evaluated data libraries but not all isotopes up to 200 MeV Davide Mancusi EXTEND th August 2016 PAGE 41

42 MODELS FOR SPALLATION REACTIONS intra-nuclear cascade sequence of independent N-N collisions λ de Broglie =ħc/p Λ mean free path fast process (tens of fm/c) heating of the nucleus - thermalisation de-excitation by evaporation or fission statistical evaporation models slow process (hundreds of fm/c) Davide Mancusi EXTEND th August 2016 PAGE 42

43 INTRA-NUCLEAR CASCADE MODELS basic assumptions classical trajectories de Broglie wave length λ inter-nucleon distance (~1 fm) independent collisions: λ Λ mean free path between collisions (= 1/ρσ NN + Pauli) many scatterings: R Λ central collision proton on 208 Pb ξ=λ/(10λ) Yariv et al., proceedings ND2007, Nice Davide Mancusi EXTEND th August 2016 PAGE 43

44 INTRA-NUCLEAR CASCADE MODELS common features straight-line trajectory between collisions nuclear potential free N-N cross-sections inelastic collisions NN NΔ Δ Nπ, etc. Pauli blocking main available INC models Bertini (Phys. Rev. 131 (1963) 1801) Isabel (Yariv and Frankel, PRCC20 (1979) 2227) INCL (D. Mancusi et al., PRC90 (2014) ) CEM (Mashnik, AIP Conf. Proceedings 768, 1188 (2005)) Davide Mancusi EXTEND th August 2016 PAGE 44

45 DIFFERENCES AMONG THE DIFFERENT INC MODELS Bertini Isabel INCL Medium continuous continuous particles Cascade propagation collided particles time steps time steps Collision criterium mean free path mean free path minimum distance of approach Stopping criterium energy energy time Surface diffuse (3 density diffuse (16 density regions) regions) diffuse (Woods-Saxon) Pauli blocking strict globally statistic locally statistic Davide Mancusi EXTEND th August 2016 PAGE 45

46 INTRA-NUCLEAR CASCADE determines the number and direction of the high energy particles shielding against energetic neutrons inter-nuclear cascade propagation INC neutrons = 15% total number but 80% total energy (Pb) determines initial conditions for evaporation-fission excitation energy Z, A of the pre-fragment angular momentum Davide Mancusi EXTEND th August 2016 PAGE 46

47 THE LIÈGE INC MODEL (INCL) no really free parameters stopping time fixed by consideration on the variation rate of several observables results insensitive to small variations potential = 45 MeV (E F +S) could be slightly varied Davide Mancusi EXTEND th August 2016 PAGE 47

48 EVAPORATION MODELS Weisskopf-Ewing formalism detailed-balance principle: A (A-a) + a (A-a) + a A ρ A P Aa = ρ (A-a) P (A-a)a ρ A, ρ (A-a) densities of nuclear states probability of emission of particle a with energy ε : P a (ε) = ρ (A-a) (E f *)/ρ A (E i *) (2s+1)(4πp 2 /h 3 ) σ c (ε) σ c (ε) inverse cross-section main available evaporation-fission models GEMINI++ (Charity, INDC(NDC) (2008)) ABLA07 (Kelic-Heil et al., INDC(NDC)-0530 (2008)) GEM (Furihata et al., Nucl. Instr. and Meth. in Phys. Res. B 171, 251 (2000)) Davide Mancusi EXTEND th August 2016 PAGE 48

49 FISSION MODELS Bohr-Wheeler formalism evaporation/fission competition governed by partial decay width fission width Γ f (E) = (1/2π ρ c ) T sad ρ sad (E-B f ) Davide Mancusi EXTEND th August 2016 PAGE 49

50 RECENT RESULTS large amount of high-quality data collected neutron and light charged particle production, isotopic residue distributions, excitation functions improvement of nuclear models INCL/ABLA tested against all the available data with the same set of parameters but also FLUKA and CEM incorporation of INCL/ABLA and CEM in MCNPX incorporation of INCL in PHITS INCL++ (C++ redesign of INCL) available in Geant4 extension of INCL++ to light-ion-induced reactions IAEA benchmark of spallation models Davide Mancusi EXTEND th August 2016 PAGE 50

51 STATE OF THE ART neutron production: can be predicted with a 10-20% precision by most of the models hydrogen: overall good agreement Davide Mancusi EXTEND th August 2016 PAGE 51

52 NEUTRON PRODUCTION calculations with INCL/ABLA and Bertini/Dresner in LAHET3. Data: S.Leray et al., Phys. Rev. C 65 (2002) Davide Mancusi EXTEND th August 2016 PAGE 52

53 NEUTRON PRODUCTION energy and angular distribution : general trends well understood T. Aoust et al., ND2004, Santa Fe Davide Mancusi EXTEND th August 2016 PAGE 53

54 STATE OF THE ART residues: new data obtained with the inverse kinematics methods considerable progress in reaction modelling models for heavy evaporation residues, generally good very close to the target nucleus total activity prediction ok fission fragments activity of volatile elements light evaporation residues: most models generally bad, but improving intermediate mass fragments: most models orders of magnitude wrong, but improving Davide Mancusi EXTEND th August 2016 PAGE 54

55 INVERSE-KINEMATICS EXPERIMENTS FRS experiments at GSI (GSI, Santiago Univ., CEA, IN2P3) Davide Mancusi EXTEND th August 2016 PAGE 55

56 INVERSE-KINEMATICS EXPERIMENTS K.H. Schmidt proceedings ND2007 Nice (2007) Davide Mancusi EXTEND th August 2016 PAGE 56

57 RESIDUE PRODUCTION: HEAVY SYSTEMS Data from Enqvist et al. INCL4/ABLA agrees much better with GSI data than Bertini/Dresner for fission fragments, very heavy residues and isotopic distribution shape both fail for light evaporation residues and intermediate mass fragments Data from Michel et al. Davide Mancusi EXTEND th August 2016 PAGE 57

58 RESIDUES CLOSE TO THE TARGET activity in the MEGAPIE target calculation with INCL4/ABLA (S. Lemaire et al., ND2007, Nice) similar results with other models Davide Mancusi EXTEND th August 2016 PAGE 58

59 VOLATILE ISOTOPE PRODUCTION data: Michel et al. Hg Xe results from ISOLDE, p + Pb-Bi 1400 MeV L. Zanini et al., ND2004 Santa Fe Davide Mancusi EXTEND th August 2016 PAGE 59

60 RESIDUE PRODUCTION: LIGHT SYSTEMS INCL + ABLA07 INCL + GEMINI which includes an asymmetrical fission mode for light nuclei (Charity et al., NPA 483 (1988) 371) INCL + SMM a multifragmentation model (A. Botvina et al., NPA 507, 649 (1990)) 1 AGeV 56 Fe + p data: C.Villagrasa et al., PRC 75 (2007) Napolitani et al. PRC 70 (2004) Le Gentil et al. PRL 100 (2008) models: DM et al., PRC 84 (2011) Davide Mancusi EXTEND th August 2016 PAGE 60

61 RESIDUE PRODUCTION: LIGHT SYSTEMS INCL + ABLA07 INCL + GEMINI which includes an asymmetrical fission mode for light nuclei (Charity et al., NPA 483 (1988) 371) INCL + SMM a multifragmentation model (A. Botvina et al., NPA 507, 649 (1990)) 1 AGeV 136 Xe + p data: Napolitani et al. PRC 76 (2007) models: DM et al., PRC 84 (2011) Davide Mancusi EXTEND th August 2016 PAGE 61

62 RESIDUE RECOIL VELOCITIES A. Boudard et al., PRC87 (2013) Davide Mancusi EXTEND th August 2016 PAGE 62

63 STATE OF THE ART light charged particles: improving, but far from perfect Davide Mancusi EXTEND th August 2016 PAGE 63

64 ACTIVITY IN A THICK PB-BI TARGET (MEGAPIE) activity in the MEGAPIE target S. Lemaire et al., ND2007, Nice Davide Mancusi EXTEND th August 2016 PAGE 64

65 CLUSTER EMISSION data: Herbach et al., Nucl. Phys. A 765 (2006) 426 data: Bertrand and Peelle, PRC 8 (1973) 1045 Model: INCL-ABLA Leray et al., NIM B268 (2010) 581 Davide Mancusi EXTEND th August 2016 PAGE 65

66 GAS PRODUCTION IN FE He 3 H INCL-ABLA07 now produces tritium situation improved compared to legacy MCNPX models Leray et al., NIM B268 (2010) 581 Davide Mancusi EXTEND th August 2016 PAGE 66

67 GAS PRODUCTION IN FE 4 He 3 H INCL-ABLA07 now produces tritium situation improved compared to legacy MCNPX models Leray et al., NIM B268 (2010) 581 Davide Mancusi EXTEND th August 2016 PAGE 67

68 CONCLUSION specific features of spallation reactions: high energy particles, huge number of produced residues, high gas production necessity of good physics models validated on good experimental data to be implemented in simulation codes present predictions of currently used models acceptable for neutron production and heavy residues, only new models good for fission residues, helium and light residues Davide Mancusi EXTEND th August 2016 PAGE 68