National Science Center Kharkov Institute of Physics and Technology National Academy of Sciences of Ukraine

Transcription

1 National Science Center Kharkov Institute of Physics and Technology National Academy of Sciences of Ukraine

2 National Science Center Kharkov Institute of Physics and Technology Mechanism of Negative Reactivity Feedback in Nuclear Burning Wave Reactor Sergii Fomin, A. Fomin, Yu. Mel nik, V. Pilipenko, N. Shul ga Akhiezer Institute for Theoretical Physics, NSC KIPT, Kharkov, Ukraine IAEA TWG-FR Feb 2012 IAEA Vienna

3 Contents: The NBW concept Brief historical review Mathematical approaches Results of our calculations Negative reactivity feedback Main features of the NBW reactor Summary

4 Lev Feoktistov (USSR, 1988): Nuclear Burning Wave L.P. Feoktistov. Preprint IAE-4605/4, L.P. Feoktistov. Sov. Phys. Doklady, 34 (1989) Concept & Analytical approach ( σa8 8 ( σa σ f ) ) 2 n n = D + vn N + N 2 t z N t 8 N t = vnσ a8n ; 8 N t 9 1 = vnσ N N 1 = N vn( σ a + σ f ) N τ β 9 a8 8 9 τ β Nuclear ashes zone Extinction zone Burning zone Breeding zone Fertile zone 238 U (n,γ) 239 U (β) 239 Np (β) 239 (n,fission)... N N cr = σ ain i = ( ν 1) σ σ N a8 8 eq σ f + σ a i f T 1/ days N x = z + Vt eq > N Feoktistov criterion cr Edward Teller (USA, 1997): Traveling Wave Reactor Monte Carlo simulation E.Teller. Preprint UCRL-JC , LLNL, Th (n,γ) 233 Th (β) 233 Pa (β) 233 U (n,fission)... T 1/2 27 days Hiroshi Sekimoto (Japan, 2001): CANDLE Deterministic approach H.Sekimoto et al., Nucl. Sci. Eng., 139 (2001) 306. U- fuel cycle, Stationary problem: x = z + Vt H. Sekimoto, Light a CANDLE, 2005: CANDLE burnup has not been achieved with thorium!???

5 Technology Entertainment Design, USA (February 12, 2010)

6 Reactors Start to Spread in Waves Around the World Map of World s Nuclear Power Plants 6

7 1A-1-2: Sustainable Burning Reactors - Chairs: Kevan Weaver (TerraPower, USA) Traveling-Wave Reactors: Challenges and Opportunities - Kevan Weaver et al. (TerraPower, USA) Feasibility of LBE Cooled Breed and Burn Reactors - Ehud Greenspan (UC, Berkeley, USA) Preliminary Engineering Design of Sodium-Cooled CANDLE Core - Hiroshi Sekimoto (TIT, Japan) Nuclear Burning Wave in Fast Reactor with Mixed Th-U Fuel - Sergii Fomin et al (NSC KIPT, Ukraine) Nuclear Traveling Wave in a Supercritical Water Cooled Fast Reactor W. Maschek (KIT, Germany) Development and Prospects of TWR Project in China - Zheng Mingguang (Shanghai NER&DI, China) Special Presentation: Traveling-Wave Reactors - John Gilliland. (Director of TerraPower, USA) 1A-3: Thorium Fuel Reactors - Chair: Sergii Fomin (KIPT, Ukraine) (Th-U-) - Mixed Fuel Cycle and Proliferation E. Kryuchkov et al, (MEPhI, Russia) Large Scale Utilization of Thorium in Gas Cooled Reactors - V. Jagannathan (Bhabha ARC, India)...

8 History of the B n B and TWR Concepts Breed n Burn concept Traveling Wave concept S.M.Feinberg and E.P.Kunegin, 1958: "Nuclear Power Plants, Part 2, Discussion", Proc. 2nd U.N. Int. Conf. Peaceful Uses of Atomic Energy,v.9, p.447, U.N., Geneva. K.Fuchs and H.Hessel, 1961: "Uber die Moglichkeiten des Betriebs eines Natururanbrutreaktors ohne Brensttoffaufbereitung", Kernenergie, v.4, p.619. J.S.Slesarev, V.A.Stukalov, S.A.Subbotin, 1984: "Problems of development of fast reactors self-provision without fuel reprocessing", Atomkernenenergie, Kerntechnik, v.45, p.58. V.Ya.Goldin, D.Yu. Anistratov, 1992: Mathematical modelling of neutron-nuclear processes in safe reactor, Preprint IMM RAS N. 43. L.P. Feoktistov, 1988: An analysis of a concept of a physically safe reactor. Preprint IAE-4605/4; & 1989: Neutron-fission wave, Sov. Phys. Doklady, v.34, p Variant of safe reactor, Nature, v.1, p. (in Russian) A.I.Akhiezer et al.,1999: Propagation of a Nuclear Chain Reaction in the Diffusion Approximation, Physics of Atomic Nuclei, v.62, p : Slow Nuclear Burning, Problem of Atomic Science & Technology, v.6, p.272. V.Pilipenko et al ICAPP 03, Paper 3169, Spain. S.Fomin, Yu.Mel nik, V.Pilipenko, N.Shul ga, 2005 Annals of Nuclear Energy (ANE), v.32, p X.-N.Chen, W.Maschek, 2005: ANE, v.32, p B.Gaveau et al., 2005: Nucl.Eng.Design, v.235, p

9 V. Goldin, D. Anistratov (IAM, Moscow) 1992 : Non-stationary problem!! В.Я.Гольдин, Д.Ю.Анистратов, 1992.Математическое моделирование нейтронно-ядерных процессов в безопасном реакторе, Препринт ИММ АН СССР, 43; Математическое моделирование 7 (1995) 12. Composition: U- fuel - 40 %, Na 25 % Fe 35 % J ex Zone 1 Zone 2 Fuel: Fuel: 10 % 238 U 100 % 238 U 90 % 1d one-group approaximation (U- fuel cycle) C t i l i i i = λ C + β ( ν Σ ) Φ l l l f f l 0 X B L X, cm i C ( x, t = 0) = C ( x) 1 Φ Φ ( ) + Σ Φ (1 )( Σ ) Φ = i i D β ν λ C a f f l i v t x x l l β = β ( ν Σ ) / ν Σ l l i 0l l f f l f f D( x) = 1/ 3 Σ ( x) ( ) j j x σ N ( x) tr Σ = ν ν j σ j N j ( x) α j α Σ = f f j f f β l = i β i l Φ( x) Φ Φ( x) Φ ( L) + 2 D( L) = 0 (0) 2 D(0) = 2 jex x x= 0 x x= L dφ ( x) dφ ( x) / // / // D ( x) = D ( x) dx dx Φ ( x) = Φ ( x) / // Φ ( x, t = 0) = 0 0 x L 0 t T

10 Nuclide composition dynamics (U- fuel cycle) 241 Am 243 Am Np T ½ = 2,35 days T ½ = 23.5 min T ½ = 14,3 years T ½ = 4.98 hours 238 U 239 U N1 N 9 N10 = σ a1φn1, = Λ 6N 6, = σ fl NlΦ t t t l= 1,4,5,6,7 Nl = ( σ alφ + Λ l ) Nl + ( σ c( l 1) Φ + Λ( l 1) ) N( l 1), ( l = 2 8), t l σ al = σ cl + σ fl, Λ l = ln 2 / T1/ 2, Nl ( x, t = 0) = N0l ( x) The numeration of the nuclei in the U transformation chain N Nucleus 238 U 239 U 239 Np Am 241 Am FP

11 Goldin and Anistratov results of numerical calculation Ф, cm -2 s -1 N pu, cm -3

12 KIPT 2005 : Results of our calculation S.P. Fomin, Yu.P. Mel nik, V.V. Pilipenko, N.F. Shul ga. Annals of Nuclear Energy, 32 (2005) Ф, cm -2 s -1 N pu, cm -3

13 Nuclear Burning Wave in FR (1d plane geometry) S.P. Fomin, Yu.P. Mel nik, V.V. Pilipenko, N.F. Shul ga. Annals of Nuclear Energy, 32 (2005) Φ 150 t 3 a) t 4 P 150 t 3 b) t t 2 t 5, x t 2 t 5, x10 50 t 1, x t 1, x x N 4 c) B x d) 1.0 t 5 40 t4 t 5 t t 1 t2 t 3 20 t 2 t x x (a) scalar neutron flux ( cm -2 s -1 ); (b) power density (kw cm -3 ); (c) concentration of 239 ( cm -3 ); (d) depth of fuel burn-up (%) for t 1 = 1, t 2 = 80, t 3 = 100, t 4 = 140 and t 5 = 170 days. (0 x 300 cm):

14 Nuclear burning wave in cylindrical FR (buckling concept) S.P. Fomin, Yu.P. Mel nik, V.V. Pilipenko, N.F. Shul ga. Progress in Nuclear Energy, 50 (2008) 163. r R j ex 0 L ig L z Ignition zone Fuel: 238 U - 90 % % Breeding zone Fuel: 238 U -100 % Composition: U- fuel - 44 %, coolant Na (Pb-Bi) 36 %, constructional material Fe 20 % External neutron flux: j ex = cm -2 s -1

15 Results for the 5m length and 110 cm radius cylindrical FR Φ 2.0 t 3 t 4 a) P 2.0 t 3 t 4 b) 1.5 t 2,* t 2,* t t t z t z N 1.5 t 3 t 4 t 5 c) B d) t 3 t 4 t t 1 t 2 5 t z z (a)scalar neutron flux flux ( 10 ( cm 16-2 cm s -1 ); -2 s -1 ); (b) power (b) density power (kw density cm -3 );(kw cm -3 ); (c) concentration of 239 of 239 ( ( 10 cm ); cm -3 (d) ); depth (d) of depth fuel burn-up of fuel (%) burn-up (%) for for t 1 for = 5, t t 2 = 100, t 3 = 2000, t 4 = 4000 and t 5 = 5000 days. 1 = 5, t 2 = 100, t 3 = 2000, t 4 = 4000 and t 5 = 5000 days.

16 Nuclear burning wave in 5m length cylindrical FR for different reactor radius R S. Fomin et al., Progress in Nuclear Energy, 50 (2008) NBW velocity V, cm/day Integral neutron flux Ф I, cm -1 s -1 V Φ I a) t, day t, day R = 150 cm (red line) ; 120 cm (green line) ; R = 110 cm (blue line)

17 Fuel burn-up Fission products U

18 R j ext r 238 U 90 % Non-Stationary Theory of Nuclear Burning Wave S. Fomin, Yu. Mel nik, V. Pilipenko, N. Shul ga, A. Fomin (1st IC Global 2009, Paris, paper 9456) 238 U 100 % % L ign L z Ignition zone Breeding zone Nuclear Burning Wave N Non-Stationary Non-Linear Multi-Group Diffusion Equation of Neutron Transport g g g 1 Φ 1 g Φ g Φ g g g g g g g 1 g 1 rd D + g ( Σ a + Σ in + Σmod Σin ) Φ ΣmodΦ = v t r r r z z G G g 1 g g g j j g g j j j g g g f ( f f ) ( ) j d l l f f l j d l l Cl in / / / g = 1 g = 1 g = 1 / / / / / / = χ ν Σ Φ χ β ν Σ Φ + χ λ + Σ Φ Together with Fuel Burn-up Equations and Equations of Nuclear Kinetics l g g g g = σ alφ + Λ l Nl + σ c( l 1) Φ + Λ( l 1) N( l 1) t g g of Precursor Nuclei of Delayed Neutrons C t j l = λ C + β ( ν Σ ) Φ j j j g g g l l l f f l g N t 9, ( l = 1 8); = Λ6N6 ; N 10 g g = σ flφ t l= 1,4,5,6,7 g N l Metal fuel (44%) Pb-Bi coolant (36%) CM - Fe (20%)

19 Reactor variant: R=117 cm, L= 500 cm (L ig = сm), t off =950 days,10 17 cм -2 с -1,10 21 cм -3

20 The 2D-distribution N U (r,z) ( cm -3 ) of the 238 U isotope in the NBW regime at different time moments

21 Dependence of the NBW velocity V on the reactor radius R S. Fomin et al., Global 2009 (Paris, France) paper 9456 V, cm/day Radial buckling 2D model R, cm

22 Reactor Power Operating by Reflector Efficiency: 130 R=110 cm vel (cm/year) ref 100 cm ref 90 cm ref 80 cm ref 70 cm ref 60 cm ref 50 cm ref 40 cm t (days)

23 Th-U fuel cycle 237 Np T ½ = 6.75 days 233 U 234 U 235 U 236 U 237 U 233 Pa T ½ = 27 days 232 Th 233 Th T ½ = 22.2 min 241 Am 243 Am T ½ = 14,3 years T ½ = 4.98 hours Np T ½ = 2,35 days 238 U 239 U T ½ = 23.5 min U- fuel cycle

24 Nuclear Burning Wave in re Th-U medium Cylindrical reactor: R=350 cm, L= 500 cm (L ig = 70.71сm). Scalar neutron flux Ф, cm -2 s -1 ; Uranium concentration N U, cm -3 j ex ~10 12 cm -2 s -1 t off =365 days Black 233 U Red total U z, cm

25 No Wave in Th-U medium with 10% CM (Fe), 20% Coolant (He) Cylindrical reactor R = 400 cm, L = 500 cm (L ig = 247 сm). Scalar neutron flux Ф, cm -2 s -1 ; uranium concentration N U, cm -3. j ex ~10 12 cm -2 s -1 t off =365 days. Black 233 U Red total U z, cm

26 NBW reactor with mixed Th-U- fuel cycle S. Fomin et al., Progress in Nuclear Energy, 53 (2011) R r J ext 238 U 90 % 238 U 50 % % L зап 232 Th 50 % L z Ignition zone Breeding zone Example: Metallic fuel 232 Th (62%) U (48%) volume fraction = 55%, Fuel porosity p = 0.8; Coolant (Pb-Bi eutectic) vol. frac. = 30%, Constr. materials (Fe) vol. frac. = 15%; R = 230 cm

27 NBW reactor with mixed Th-U- fuel cycle and Pb-Bi coolant S. Fomin et al., Progress in Nuclear Energy, 53 (2011) Φ 8 7 t 2, 0.04 t 3 a) B 50 c) t 1 t 4 t 5 t 6 t t 2 t 3 t 4 t 5 t 6 t 7 N z t 1 t 3 t 4 t 5 t 6 t 7 t z b) z a) Scalar neutron flux Φ ( cm -2 s -1 ) b) Concentration N ( cm -3 ) for 239 (solid curves) and 233 U (dots) R = 230 cm c) Fuel burn-up depth B (%) of the U (solid curves) and Th U (dots) fuel components via z (cm) The time moments: t 1 = 3, t 2 = 100 days, t 3 = 5, t 4 = 10, t 5 = 20, t 6 = 40, and t 7 = 55 years.

28 NBW reactor with mixed Th-U- fuel cycle and Pb-Bi coolant S. Fomin et al., Progress in Nuclear Energy, 53 (2011) V а) F 4 c) P int b) t t z a) The NBW velocity V (cm/year) via time t (years) b) Total FR power P int (GW) via time t (years) c) Neutron fluence F ( cm -2 ) via z (cm) For different FR radiuse: R = 250 cm - dots, R = 230 cm - solid curves R = 215 cm - dashed curves

29 Fuel burn-up for Th-U- cycle

30 Main features of NBW reactor with mixed Th-U- fuel cycle Reactor composition (vol. frac.): Fuel = 55% (F Th = 62%, p = 0.80), Coolant = 30%, CM = 15%, R = 215 cm - negative feedback on reactivity - intrinsic safety - long-term (decades) operation without refueling and external control - possibility of 232 Th and 238 U utilization as a fuel - fuel burn-up depth for both 238 U and 232 Th 50% - neutron flux in active zone n/сm 2 s - neutron fluence during the whole reactor campaign n/сm 2 - energy production density in active zone 200 W/сm 3 - total power at the steady-state regime 1.2 GW - wave velocity at the steady-state regime 2сm/year - possibility of nuclear waste burn out (expected)

31 Negative Reactivity Feedback: Inherent Safety of the NBW Reactor Φ I, cm -1 s -1 3 U - fuel cycle T off = 10 days Φ I, cm s Th - U fuel cycle T off = 100 days τ 3 days τ 15 days t, days t, days For the mixed Th-U- fuel cycle τ =?

32 Negative Reactivity Feedback of the NBW Reactor Φ int 30 a) < z < 170 cm Φ int < z < 65 cm c) t-t Φ int < z < 210 cm c) R = 230 cm Perturbation of integral neutron flux Fint ( cm/s) caused by an external neutron source via time t (days). The source with intensity Q ext = (cm -3 s -1 ) starts at t 0 = 3650 days, lasts during one hour and is situated at а) 160 < z < 170 cm, b) 200 < z < 210 cm, c) 55 < z < 65 cm. t-t t-t 0

33 Negative Reactivity Feedback R = 230 cm N ( cm -3 ) Q ext : 160 < z < 170 cm Φ int ( cm s -1 ) 0,33 0,30 0,27 0,24 Φ int N Np ~ N Pa ~ N ~ N U ~ N Pa = N Pa (t) 2,2 0,21 0,18 0,15 0, ,03 ~ 0,00 N = N (t) - N (t 0-1) ~ N U = N U (t) - N U (t 0-1) t 0 = 3650 days t - 0 t, days Q ext = (cm -3 s -1 ) t = 1 hour 5

34 Negative Reactivity Feedback: Stability of the NBW Regime

35 Negative Reactivity Feedback: Stability of the NBW Regime

36 Negative Reactivity Feedback: Stability of the NBW Regime P int, GW % Th, R=230 cm, 5% brick, z= cm 62% Th, R=230 cm, 10% brick, z= cm t, years

37 Smooth Startup of the NBW Reactor (10-3 b -1 cm -1 ) (10-3 b -1 cm -1 ) 238 U/8 238 U/8 239 Pb-Bi 239 Pb-Bi 181 Ta

38 Smooth Startup of the NBW Reactor P I, GW P I, GW 4,0 3,5 3,0 2,5 2,0 1,5 1,0 0, t t, days

39 Thank you for attention! Our blications: S. Fomin et al., Annals of Nuclear Energy, 32 (2005) S. Fomin et al., Problems of Atomic Science & Technology, 6 (2005) S. Fomin et al., Nuclear Science & Safety in Europe. Springer (2006) S. Fomin et al., Problems of Atomic Science & Technology, 3 (2007) S. Fomin et al., Progress in Nuclear Energy, 50 (2008) Yu.Mel nik et al., Atomic Energy, 107 (2009) (in Russian) S. Fomin et al., Progress in Nuclear Energy, 53 (2011) S. Fomin et al., Nuclear Engineering and Design, (2012) in print.

40 INES-3 John Gilleland (TerraPower, USA) Pilot reactor TerraPower-1 Ignition zone

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