Monte Carlo simulations of artificial transmutation for medical isotope production, photofission and nuclear waste management

Transcription

1 Monte Carlo simulations of artificial transmutation for medical isotope production, photofission and nuclear waste management Laser Electron Scatter Photons at Light Sources for Nuclear & Allied Research, April 23, 2010, CLS Barbara Szpunar

2 Collaborative project Project initialized by professor Chary Rangacharyulu Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, SK S7N 5E2

3 The FLUKA International Collaboration UPDATES ON THE STATUS OF THE FLUKA MONTE CARLO TRANSPORT CODE A. Ferrari, M.Lorenzo-Sentis, S. Roesler, G. Smirnov, F.Sommerer, C.Theis and V.Vlachoudis, CERN, Geneva, Switzerland M. Carboni, A. Mostacci, M. Pelliccioni and R. Villari, INFN, Frascati, Italy V. Anderson, N. Elkhayari, A. Empl, K. Lee, B. Mayes, L. Pinsky and N. Zapp Physics Department, University of Houston, Houston, TX , USA K. Parodi, H. Paganetti and T. Bortfeld, Massachusetts General Hospital, Department of Radiation Oncology, Boston, MA, USA G. Battistoni, M. Campanella, F. Cerutti, P. Colleoni, E. Gadioli, M.V. Garzelli, M. Lanza, S.Muraro, A. Pepe and P. Sala, INFN and Univ. of Milan, Italy T. N. Wilson. NASA/JSC, Houston, TX, USA D. Alloni, F. Ballarini, M. Liotta, A. Mairani, A. Ottolenghi, D. Scannicchio and S. Trovati, INFN and Univ. Pavia, Italy J. Ranft, Siegen Univ., Germany A. Fasso, SLAC, USA

4 Content Background on FLUKA simulation method Photon induced artificial transmutation medical isotope production photofission nuclear waste management Summary and conclusions

5 FLUKA Main authors:a. Fassò, A. Ferrari, J. Ranft, P.R. Sala Contributing authors: G.Battistoni, F.Cerutti, T.Empl, M.V.Garzelli, M.Lantz, A. Mairani, V.Patera, S.Roesler, G. Smirnov, F.Sommerer, V.Vlachoudis >2000 users Developed and maintained under an INFN-CERN agreement Copyright CERN and INFN

6 FLUKA code FLUKA (FLUktuierende KAskade), fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter Well tested models Optimized by comparing with experimental data Fully analogue code or biased mode Double precision used, energy conservation 60 particles modeled including polarized light First Monte Carlo particle transport code with photonuclear interactions: MeV TeV energy range

7 FLUKA2008.3b version Giant Dipole Resonance (GDR) cross sections, the library for energy range between 6 and 60 MeV (0.2 MeV) The libraries professionally evaluated (e.g. IAEA ); corrected for consistency Statistically selected evaporation or fission models No fission for nuclei with Z less than 70 (65) Not up-to-date photofission model; heavily underestimated for low energy photons

8 Photonuclear reaction (GDR) E 80 Typical nuclear excitation spectrum Energy / Width [MeV] Energy Width 77*A -1/3 [MeV] 20 77*A -1/3 23*A -1/3 0 Excitation Energy Atomic mass

9 Medical Isotopes (photons versus protons) Cross Sections [barns] Cross Sections [barns] 0.6 1e+5 1e e e+2 1e e e-1 1e Mo, (,n) 99 Mo 100 Mo (p,2n) 99m 100 Tc Mo, (,n) 99 Mo 193 Ir (,n) 192 Ir 100 Mo (p,2n) 99m Tc 193 Ir (,n) 192 Ir 98 Mo(n, ) 99 Mo 191 Ir(n, ) 192 Ir 1e e-4 1e-8 5 1e-7 1e e e-4 1e e-2 1e-1 251e+0 1e+1 30 Incident Energy [MeV]

10 I: FLUKA hybrid simulations Five runs (each 10 6 particles, GDR energy) Energy deposition, equivalent dose Fluence (n = L particle / V target dn/dlne): neutron, photon, proton Residual nuclei (R n - per particle) No time dependence Time dependence Calculate induced activity for a given beam intensity (I) t / N ( t t ) R (1 e ) i dn ( t ti ) ti i R(1 e ) e dt / ( t t ) / R = I * R n t i irradiation time τ mean life Activity N (t) = N(t) Activity atom

11 II: FLUKA induced activity simulations Set irradiation and cooling time, beam intensity Perform five runs using FLUKA s exact analytical implementation of Bateman equations for induced activity calculations Total activity Yield Time dependence

12 Photonuclear GDR interaction in natural Ir and 193 Ir (target: 1cm (d) x 4 cm (h)) (CNS 2010) Natural Ir (37% of 191 Ir and 63% of 193 Ir) 192 Ir, T 1/2 = d 193 Ir target

13 193 Ir target Natural Ir, n reflected by Be Produced Produced Isotope Isotope Yield Yield [per [per one one Error Error (reaction) (reaction) photon/cm photon/cm ] 3 ] [%] [%] (n,γ) 194 Ir # Pb container 1.33x (n,γ) 194 Ir # 1.23x (γ,e + e - ) 193 (γ,e + e - atomic Ir 1.28x ) 193 atomic Ir 1.26x (γ,n) 192 Ir (γ,n) or (n,γ)* 192 Ir 2.04x x (γ,2n) (γ,2n) 191 Ir Ir 9.16x x (γ,3n) (γ,p) Os Ir 1.97x10 7.6x Produced Isotope (reaction) #Secondary neutron capture * 191 Ir Yield [per one photon/cm 3 ] Error [%] (n,γ) 194 Ir # 3.44x (γ,e + e - ) atomic 193 Ir 1.29x (γ,n) or (n,γ)* 192 Ir 1.32x (γ,2n) 191 Ir 8.87x (γ,3n) 190 Ir 7.56x Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 194 Ir # 3.19x (γ,e + e - ) atomic 193 Ir 1.29x (γ,n) or (n,γ)* 192 Ir 1.31x (γ,2n) 191 Ir 9.06x (γ,3n) 190 Ir 7.51x (γ,p) 190 Os 2.0x (37% of 191 Ir and 63% of 193 Ir) (Reaction) Produced Isotope Yield [per one photon/cm 3 ] Error [%] (n,γ) 194 Ir # 3.52x (γ,e + e - ) atomic 193 Ir 1.29x (γ,n) or (n,γ)* 192 Ir 1.33x (γ,2n) 191 Ir 8.92x (γ,3n) 190 Ir 7.55x

14 FLUKA; Proton versus photon 100 Mo transmutation; Geometry (target: 1.2 cm (d) x 3.6 cm (h)), energy deposition (p,2n) 22 MeV 14.8 MeV (γ,n) Natural Mo: 9.63% 100 Mo, 24.13% 98 Mo

15 FLUKA; Proton versus photon 100 Mo transmutation; Equivalent dose (p,2n) (γ,n) W n : 10 (2-20 MeV), 5 (above) and 20 (below this energy)

16 Produced Isotope (reaction) FLUKA; Proton versus photon 100 Mo Yield [per one proton/cm photon/cm 3 ] 3 ] Natural 100 Mo target Mo target Pb Be container transmutation Error [%] (n,γ) (p,n) Mo Tc # 5.44x x Produced Isotope (reaction) Yield [per one photon/cm 3 ] 100 Mo target Pb container Error [%] (n,γ) 101 Mo # 3.65 x (γ,e(p,2n) + e - ) 99 Tc x atomic Mo 6.32 x (~ 2x m Tc) (γ,n)&(n,γ)# (p,3n) 98 Tc Mo 7.23x x (γ,2n)&(γ,γ)* (n,γ) 101 Mo Mo # 7.07 x x (γ,3n)&(γ,n)* 97 Mo 4.71 x (p,p) 100 Mo 2.09x (γ,4n)&(γ,2n)* 96 Mo 2.15 x (p,n&p) 99 Mo (γ,5n)&(γ,3n)* 95 Mo 9.42x10 -h x #Secondary neutron capture; * 98 Mo (γ,e + e - ) 100 atomic Mo 7.85 x (γ,n) 99 Mo 1.31 x (γ,2n) 98 Mo 6.06 x (γ,3n) 97 Mo 9.27 x (γ,4n) 96 Mo 1.04 x Natural Mo: 9.63% 100 Mo, 24.13% 98 Mo

17 FLUKA hybrid versus FLUKA calculations Photonuclear (14.8 MeV) transmutation ( 100 Mo ( n) 99 Mo) (10 12 photons/s) 6 x atoms in 1g of Mo Number of atoms per g 4.5e e e e e e e+14 Hybrid FLUKA ( 99 Mo) FLUKA ( 99 Mo) FLUKA ( 99m Tc) NRU produces (in reactor) per year : ~3.65 x Mo atoms ~24 g Mo with 25% 99 Mo Burns 10% of 10 kg HEU (90%, Al) uranium Waste: 9kg HEU N(t) = Activity g (t)/activity atom 1.0e e Time [hrs] Target s weight: 41.6 g Target Irradiation 99 Mo 99 Mo 99m Tc 99m T 100 Mo Time [hrs] Activity [Bq/cm 3 ] Activity [Ci/g] Activity [Bq/cm 3 ] Activity [Ci/g] 99 Mo, T 1/ x x h x x m Tc, T 1/ x x h x x

18 FLUKA; Photon induced activity Induced (14.8 MeV) total activity ( 100 Mo ( n) 99 Mo) (10 12 photons/s) 99 Mo Activity [Ci/g] FLUKA hybrid ( 99 Mo induced activity) FLUKA hybrid, decay 1 FLUKA, decay 1 FLUKA hybrid, decay 2 FLUKA, decay 2 FLUKA hybrid, decay 3 FLUKA, decay 3 FLUKA hybrid, decay 4 FLUKA, decay 4 FLUKA ( 99m Tc) FLUKA ( 99 Mo) T 1/2 = h 99m Tc T 1/2 = h Time [hrs] Target s weight: 41.6 g

19 Photofission versus GDR transmutation Photons (16 MeV) Fission yield per one photon [Nuclei/cm 3 ] (May be heavily underestimated by the FLUKA currently!) β - yield Target 99 Mo(42) 99 Kr(36) 99 Rb(37) 99 Sr (38) 99 Y(39) 99 Zr(40) 99 Nb(41) 99 Mo(42) 238 U 1.17x x x x x x x x10-4 Errors (%) Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 101 Mo # 3.65 x (γ,e + e - ) 100 atomic Mo 7.85 x (γ,n) 99 Mo 1.31 x (γ,2n) 98 Mo 6.06 x #Secondary neutron capture

20 Fission in FLUKA (geometry, target: 12 cm (d) x 6 cm (h))

21 Symmetric versus asymmetric fission % % Jerry Montgomery Rondo Jeffery m

22 FLUKA photofission not updated yet Photofission 1e U (12.5 MeV) 238 U(16 MeV) Fission Yield per Photon [Nuclei/cm 3 ] 1e-2 1e-3 1e-4 1e-5 1e-6 1e-7 1e-8 1e U(12.5 MeV) 235 U(16 MeV) 234 U(12.5 MeV) 234 U(16 MeV) 232 Th(12.5 MeV) 232 Th(16 MeV) Atomic Mass (A) Fission Yield per Photon [Nuclei/cm 3 ] 1e-2 1e-3 1e-4 1e-5 Photofission 1e U (12.5 MeV) 238 U(16 MeV) 235 U(12.5 MeV) 1e U(16 MeV) 234 U(12.5 MeV) 1e U(16 MeV) 232 Th(12.5 MeV) 232 Th(16 MeV) 1e Atomic Mass (A)

23 FLUKA photofission not updated yet

24 99 Mo production in photofission Photons (16 MeV) Subcritical fission yield per one particle [nuclei/cm 3 ] May be heavily underestimated by FLUKA currently! β - yield* Target 99 Mo(42) 99 Kr(36) 99 Rb(37) 99 Sr (38) 99 Y(39) 99 Zr(40) 99 Nb(41) 99 Mo(42) 238 U 1.16x x x x x x x x10-4 Errors (%) U 1.04x x x x x x x x10-3 Errors (%) U 9.83x x x x x x x x10-3 Errors (%) Th 1.19x x x x x x x x10-5 Errors (%)

25 Thermal neutrons 99 Mo production comparison Target 0.12 m diameter and 0.06 m height Fission (subcritical) yield per one neutron [nuclei/cm 3 ] β - yield* Total Target 99 Mo(42) 99 Rb(37) 99 Sr (38) 99 Y(39) 99 Zr(40) 99 Nb(41) 99 Mo(42) 99 Mo(42) 235 U 7.01 x x Errors (%) GDR Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 101 Mo # 6.88 x (γ,e + e - ) 100 atomic Mo 7.69 x (γ,n) 99 Mo 1.58 x (γ,2n) 98 Mo 8.47 x (γ,3n) 97 Mo 9.71 x (γ,4n) 96 Mo 1.11 x (γ,5n) 95 Mo 1.75 x

26 Internal part of container Energy deposition in 99 Mo production Thermal neutrons (0.025 ev) Average Energy Error Standard Deviation 235 U Target GeV/particle [%] GeV/particle Target Internal part of the lead container x10-5 External part of the lead container x10-5 GDR ( MeV) Average Energy Error Standard Deviation 100 Mo Target GeV/particle [%] GeV/particle Target x10-6 Internal part of the lead container x10-6 External part of the lead container 1.29 x x10-8

27 GDR, photofission versus thermal neutrons fission (subcritical); Energy deposition

28 Photofission versus thermal neutrons fission (subcritical); Fluence No protons

29 Waste management Treatment of long lived isotopes: 79 Se, 93 Zr, 99 Tc, 107 Pd, 126 Sn, 129 I and 135 Cs; radio-toxic >10 5 years GDR transmutation to short live isotopes 2.3 x10 6 years half-life time of 135 Cs to years 134 Cs or d 136 Cs (secondary neutron capture) 1.57 x10 7 years half-life time of 129 I to m 128 I or h 130 I (secondary neutron capture)

30 Photons versus neutrons I (,n) 128 I 129 I(n, ) 130 I 135 Cs(n, ) 136 Cs Cross Sections [barns] e-8 1e-7 1e-6 1e-5 1e-4 1e-3 1e-2 1e-1 1e+0 1e+1 Incident Energy [MeV]

31 Long lived waste transmutation; Geometry (target: 12 cm (d) x 15 cm (h) )

32 135 Cs transmutation by GDR (15.01 MeV ) Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 136 Cs # 4.42 x (γ,e + e - ) atomic 135 Cs 1.45 x (γ,n) 134 Cs 2.21 x (γ,2n) 133 Cs 2.81 x (γ,p) 134 Xe 3.60 x #Secondary neutron capture 2.3 x10 6 years half-life time of 135 Cs years 134 Cs or d 136 Cs (secondary neutron capture) Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 136 Cs # 3.52 x (γ,e + e - ) atomic 135 Cs 1.41 x (γ,n) 134 Cs 2.19 x (γ,2n) 133 Cs 2.76 x (γ,p) 134 Xe 2.20 x Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 136 Cs # 1.35 x (γ,e + e - ) atomic 135 Cs 1.67 x (γ,n) 134 Cs 2.22 x (γ,2n) 133 Cs 2.76 x (γ,p) 134 Xe 3.00 x

33 129 I transmutation by GDR (15.24 MeV ) Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 130 I # 9.22 x (γ,e + e - ) atomic 129 I 6.15 x (γ,n) 128 I 2.88 x (γ,2n) 127 I 9.88 x (γ,p) 128 Te 3.20 x #Secondary neutron capture 1.57 x10 7 years half-life time of 129 I m 128 I or h 130 I (secondary neutron capture) Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 130 I # 7.91 x (γ,e + e - ) atomic 129 I 6.17 x (γ,n) 128 I 2.90 x (γ,2n) 127 I 9.87 x (γ,p) 128 Te 5.60 x Produced Isotope (reaction) Yield [per one photon/cm 3 ] Error [%] (n,γ) 130 I # 1.08 x (γ,e + e - ) atomic 129 I 6.81 x (γ,n) 128 I 2.88 x (γ,2n) 127 I 1.00 x (γ,p) 128 Te 2.80 x

34 Long lived waste transmutation; fluence

35 Long lived waste transmutation; fluence

36 Long lived waste transmutation; energy deposition

37 Summary and conclusion FLUKA simulations show that the production of the desired isotopes via GDR (photon) are orders of magnitude higher than the other isotopes, indicating this technique to be promising method for artificial transmutations Applications Production of medical and industrial isotopes Transmutation of long lived isotopes to short lived Induced transmutation & photofission as a source of neutrons Comment: Currently γ beams have too low intensity for some applications. While it is expected that the intensity will be increased sufficiently for a production of medical isotopes, the total transmutation of nuclear waste requires intensities that will be probably not possible to achieve in the near future.

38 Acknowledgement Collaboration with Professor Chary Rangacharyulu Access to FLUKA code FLUKA developers and support group (especially Francesco Cerutti) V. Vlachoudis for FLAIR graphic interface with FLUKA C. Cederstrand for technical support Science and Engineering division (especially Dean J. Kozinski and Vice-dean K. Schneider) for start up funding and support