The fission reactor and the spallation source

Transcription

1 I N S T I T U T L A U E L A N G E V I N The fission reactor and the spallation source Umbertoluca RANIERI Mushfiqur RAHMAN 07/02/2017 NFF seminars 1

2 Outline History: Exploiting nuclear energy Fission chain reaction The ILL research reactor Spallation revisited Historical development of spallation neutron source Operation principles of modern sources Nature of neutron beam produced Alternative sources 07/02/2017 NFF seminars 2

3 Exploiting nuclear energy: from science-fiction to reality 1911: E. Rutherford realized that a large amount of energy is released during the decay of radium. «This evolution of heat is enormous [...] The atoms of matter must consequently be regarded as containing enourmous stores of energy which are only released by the disintegration of the atom.» Ernest Rutherford, Radioactivity, in Encyclopaedia Britannica, 11th ed. 1932: The novelist H. G. Wells published the science-fiction book The World Set Free. 1933: Leó Szilárd conceived the idea of neutron chain reaction. 07/02/2017 NFF seminars 3

4 Exploiting nuclear energy: from science-fiction to reality 1938: Fission of uranium was demonstrated, O. Hahn, F. Strassman and L. Meitner. 1942: First human-made self-sustaining nuclear reactor (Chicago Pile-1), University of Chicago, E. Fermi. Reminder: - decay is : The first nuclear power plant built for civil purposes (AM-1 Obninsk Nuclear Power Plant), Soviet Union. 07/02/2017 NFF seminars 4

5 Exploiting nuclear energy: from science-fiction to reality Today: 450 nuclear power reactors are used to generate electricity in about 30 countries around the world. 07/02/2017 NFF seminars 5

6 Reminder: the fission reaction Q = [M( 235 U)-M( 144 Ba)-M( 89 Kr)-2m n ]c 2 = 173 MeV 07/02/2017 NFF seminars 6

7 Why energy? Why neutrons? 07/02/2017 NFF seminars 7

8 Mass distribution of fission fragments 2.4 neutrons produced in average per fission event 235 U + n 236 U* (A 1,Z 1 ) + (A 2,Z 2 ) + Nn+ y s Z1 + Z2 = 92 A1 + A2 + N = transmutation-and-nuclear-energy/ 07/02/2017 NFF seminars 8

9 Energy release in fission Q = [M( 235 U)-M( 144 Ba)-M( 89 Kr)-2m n ]c 2 = 173 MeV Q = MeV in average, distributed between: - kinetic energy of the fission fragments (168.2 MeV) - kinetic energy of the prompt neutrons (4.8 MeV, approx. 2 MeV per neutron) - energy carried off by prompt gamma rays (7.5 MeV) In a second time, 14.6 MeV released in the decay of the fragments, distrubuted between: - kinetic energy of the emitted - rays (7.8 MeV) - energy of the neutrinos emitted in - decay (12 MeV) - energy of the gamma rays accompanying - emission (6.8 MeV) - energy of the delayed neutrons (negligible) 195 MeV per fission event 07/02/2017 NFF seminars 9

10 Courtesy of B. Désbrieres Chain reaction 07/02/2017 NFF seminars 10

11 07/02/2017 NFF seminars 11

12 Chain reaction: moderation with H 2 O Courtesy of B. Désbrieres Fuel : 235 U Moderator: H 2 O Fuel : 235 U 12

13 S. Doege and A. Polidori Neutron moderation Es Ei = = A2 + 1 A 2 + 2A + 1 =0.5 for H (A=1) =0.56 for D (A=2) =0.86 for C (A=12) =0.99 for U (A=238) But abs (H)=0.33 barns abs (D)= barns 07/02/2017 NFF seminars 13

14 Chain reaction: moderation with D 2 O Courtesy of B. Désbrieres Fuel : 235 U Moderator: D 2 O 14

15 The multiplication factor and the six factor formula 07/02/2017 NFF seminars 15

16 The multiplication factor and the six factor formula 07/02/2017 NFF seminars 16

17 Courtesy of B. Désbrieres How to extract neutrons: beam tubes Fuel Reactor vessel: D 2 O 17

18 Courtesy of B. Désbrieres How to stop the reaction: safety rod Fuel Reactor vessel: D 2 O 18

19 Why the fuel element has a tubular shape? Courtesy of B. Désbrieres Fuel Reactor vessel: D 2 O 19

20 Power reactors vs. Reaserch reactors Courtesy of S. Doege and A. Polidori 07/02/2017 NFF seminars 20

21 Reaserch reactors around the world ~40 operational research reactors for neutron scattering around the world ( North America Oak Ridge Neutron Facilities (SNS/HFIR) Los Alamos Neutron Science Center (LANSCE) University of Missouri Research Reactor Center Canadian Neutron Beam Centre, Chalk River, Canada Indiana University Cyclotron Facility Europe ISIS-Rutherford-Appleton Laboratories, United Kingdom Institut Laue-Langevin, Grenoble, France Leon Brillouin Laboratory, Saclay, France Berlin Neutron Scattering Center, Germany GEMS at Helmholtz-Zentrum Geesthacht, Germany Juelich Center for Neutron Science, Germany FRM-II, Munich, Germany Budapest Neutron Centre, Hungary RID, Delft, The Netherlands SINQ, Paul Scherrer Institut (PSI), Switzerland Frank Laboratory of Neutron Physics, Dubna, Russia St. Petersburg Neutron Physics Institute, Gatchina, Russia Asia and Australia ISSP Neutron Scattering Laboratory, Tokai, Japan JAEA Research Reactors, Tokai, Japan KENS Neutron Scattering Facility, Tsukuba, Japan Hi-Flux Advanced Neutron Application Reactor, Korea Bhabha Atomic Research Centre, Mumbai, India Bragg Institute, ANSTO, Australia 21

22 ILL High Flux Reactor: hystorical remarks 1967: The ILL is founded on January 19 th by France and Germany 1969: Start of work on the reactor floor and walls 1971: Construction complete. The reactor went critical on August 31 st, ramping to full power on December : First experiments 1973: The UK becomes an Associate on January 1 st Today: 10 Scientific Member countries (Spain, Switzerland, Austria, Italy, the Czech Republic, Sweden, Belgium, Slovakia, Denmark, Poland) 07/02/2017 NFF seminars 22

23 ILL High Flux Reactor: essential data Thermal power 58 MW (= J s-1) Energy released per fission event 195 MeV # of fission events per second (58 MW / 195 MeV) # neutrons produced per second ( ) # of photons emitted by a 1 W bulb light per second 10 18! 07/02/2017 NFF seminars 23

24 The ILL reactor does not only produce neutrons! beta particles gamma rays (anti)neutrinos exotic nuclei The antineutrino was first confirmed experimentally in a nuclear reactor in 1956 by Frederick Reines and Clyde Cowan, Hanford nuclear site (USA). "Thanks for message. Everything comes to him who knows how to wait. Pauli." Wolfgang E. Pauli 07/02/2017 NFF seminars 24

25 ILL High Flux Reactor: containment building Rapport transparance et sécurite nucleaire, ILL /02/2017 NFF seminars 25

26 ILL High Flux Reactor: reactor vessel Rapport transparance et sécurite nucleaire, ILL /02/2017 NFF seminars 26

27 ILL High Flux Reactor: fuel element ILL4, 4 th floor 8.57 kg of Uranium (93% 235 U) Al-based alloy fuel cladding (internal diameter 39 cm, height 80 cm) Al + n th Al Si All reactor parts must be changed regularly! 07/02/2017 NFF seminars 27

28 ILL High Flux Reactor: reactor pool Cherenkov radiation 07/02/2017 NFF seminars 28

29 ILL High Flux Reactor: heavy water 2 1 H + n th 3 1 H Creation of 1.3 Ci of tritium per liter of D 2 O every year (limit value: 10 Ci.l -1 ) Necessity for detritiation of the heavy water! 07/02/2017 NFF seminars 29

30 ILL High Flux Reactor: beam tubes Located in the region where the thermal flux is maximum ( 40 cm from the core centre) But some of them face a cold or hot source 07/02/2017 NFF seminars 30

31 ILL High Flux Reactor: sources (blocks of other moderator materials at higher or lower T are used to obtain different λ) Hot source: 10 dm 3 of graphite at 2400 K Cold source (horizontal): 6 dm 3 of liquid D 2 at 25 K Cold source (vertical): 20 dm 3 of liquid D 2 at 25 K Ultracold Neutrons Cold Neutrons Reactor Neutrons Temperature (K) Energy (ev) Velocity (m/s) /02/2017 NFF seminars 31

32 ILL High Flux Reactor: guides & instruments 07/02/2017 NFF seminars Rapport transparance et sécurite nucleaire, ILL

33 Acknowledgments Ulli Koester Yoann Calzavara Bruno Désbrieres Bibliography Nuclear Energy - Principles, Practices, and Prospects, David Bodansky, AIP Press, Rapport transparance et sécurite nucleaire, ILL /02/2017 NFF seminars 33

34 Outline History: Exploiting nuclear energy Fission chain reaction The ILL research reactor Spallation revisited Historical development of spallation neutron source Operation principles of modern sources Nature of neutron beam produced Alternative sources 07/02/2017 NFF seminars 34

35 Neutrons from spallation Process of spallation-fission High-energy proton Interact with nucleondistribution of energy inside the nucleus Knock-out particles Further neutronsevaporation/fission (if possible) Courtesy L. Waters, LANL 07/02/2017 NFF seminars 35

36 Neutrons from spallation Detection of cosmic rays by Victor Hess (1912) No particle accelerator Cosmic-ray proton (~10 GeV) Balloon ride- increasing intensity of cosmic rays with higher altitude Nobel Prize in /02/2017 NFF seminars 36

37 Neutrons from spallation Cosmic neutron detection by Harold Agnew (1944) Harold Agnew (Manhattan Project) put neutron detectors in a borrowed B-29 bomber Reported data- 7,000 to 40,000 feet 29_Superfortress 07/02/2017 NFF seminars 37

38 Neutrons from spallation Atmospheric spallation neutrons (Fermi, 1948) Cosmic-ray-proton induced neutron flux as a function of atmospheric depth 10 4 ~10 3 neutron/cm 2 s Fermi, Uni. Of Chicago 1948 lectures (courtesy of J. Carpenter) 07/02/2017 NFF seminars 38

39 Courtesy of Phillip V Livdahl Accelerator-produced neutrons Historical background of accelerator based neutron source MTA Linac- electronuclear breeding of Pu 239 by irradiation of depleted uranium with accelerator-produced neutrons Courtesy of J. Carpenter Very large cavities (klystrons- 12 MHz) Now operating frequency 800 MHz Abandoned in 1956 (declassified 1957) 07/02/2017 NFF seminars 39

40 Historical development of spallation source Development of particle accelerator to produce neutrons Committee on Intense Neutron Sources (CINS) formed (1969) New information emerged- bright, negative hydrogen-ion sources, stripping injection and high-current proton synchrotron Argonne National Lab- 12 GeV Zero Gradient Synchrotron 07/02/2017 NFF seminars 40

41 Historical development of spallation source Development of particle accelerator to produce neutrons More research- Kingsley Graham s thesis ( ): data on performance of neutron moderators for pulsed sources Courtesy of J. Carpenter 07/02/2017 NFF seminars 41

42 Historical development of spallation source Development of particle accelerator to produce neutrons Improved understanding of neutron yields Work by John Fraser et al. (1965): data on spallation neutron production MCNP not available then Fraser et al. (1965) 07/02/2017 NFF seminars 42

43 Historical development of spallation source Design principles of the first spallation neutron source ZING Basis of ZING design Performance of the Booster (ZGS) Normalized ING neutron yield data Graham s normalized moderator data John Carpenter patented the ZING mock-up ZING-P developed in 1973 IPNS eventually built in neutron scattering instruments Courtesy of J. Carpenter 07/02/2017 NFF seminars 43

44 Historical development of spallation source Intense Pulsed Neutron Source based on the design of ZING-P Courtesy of J. Carpenter 07/02/2017 NFF seminars 44

45 Neutron science facilities Reactors and accelerator-based neutron sources around the world Courtesy of J. Carpenter 07/02/2017 NFF seminars 45

46 Operation principles of a pulsed source The duty cycle advantage of a pulsed spallation source Pulsed sources relate naturally to accelerators The source is on and at full power only part of the time P peak = P average f tsource E. g., for f = 20 Hz and t mod λ = 50 μs The peak flux φ peak = φ ave = 10 3 φ f t ave mod 07/02/2017 NFF seminars 46

47 Modern spallation neutron sources ISIS spallation source at the Rutherford Appleton Laboratory, Didcot, Oxfordshire 800 MeV proton accelerator Producing intense pulses 50 times a second Accelerator consists of an injector and a synchrotron 07/02/2017 NFF seminars 47

48 Modern spallation neutron sources ISIS spallation source, UK The H-ion source (courtesy: STFC UK website) The RFQ The Linac Synchrotron Target St 1 Target St 2 Source: STFC UK website 07/02/2017 NFF seminars 48

49 Modern spallation neutron sources ISIS spallation source, UK The RFQ 665 kev, MHz 4 electrodes Alternating gradient quadruple electric field for focusing and acceleration H-ions bunches are 4.94 ns apart The RFQ The Linac Synchrotron Target St 1 Target St 2 Source: STFC UK website 07/02/2017 NFF seminars 49

50 Modern spallation neutron sources ISIS spallation source, UK The Linac Four 10m long copper drift tubes 70 MeV 200 μs long, 22 ma H- pulses Exit: 37% of the speed of light The RFQ The Linac Synchrotron Target St 1 Target St 2 Source: STFC UK website 07/02/2017 NFF seminars 50

51 Modern spallation neutron sources ISIS spallation source, UK The Synchrotron 163m circumference H- ions stripped away by a thin alumina foil After 10,000 rev. H+ separated into 2 large bunches (84% of speed of light) Kicked out 100 ns The RFQ The Linac Synchrotron Target St 1 Target St 2 Source: STFC UK website 07/02/2017 NFF seminars 51

52 Modern spallation neutron sources Spallation Neutron Source at Oak Ridge National Laboratory, Tennessee, USA The Linac Source: ORNL website 07/02/2017 NFF seminars 52

53 Modern spallation neutron sources Spallation Neutron Source at Oak Ridge National Laboratory, Tennessee, USA Outside of the accumulator ring Source: ORNL website 07/02/2017 NFF seminars 53

54 Modern spallation neutron sources Spallation Neutron Source at Oak Ridge National Laboratory, Tennessee, USA Outside the target station Source: ORNL website 07/02/2017 NFF seminars 54

55 Modern spallation neutron sources Instruments at the Spallation Neutron Source at ORNL 07/02/2017 NFF seminars 55

56 Modern spallation neutron sources Japan Proton Accelerator Research Complex (J-PARC), Tokai Source: J-PARC website 07/02/2017 NFF seminars 56

57 Modern spallation neutron sources European Spallation Source, Lund, Sweden No RCS Plans to deliver first neutron by 2019 User programme in 2023 Source: ESS website 07/02/2017 NFF seminars 57

58 Modern spallation neutron sources European Spallation Source, Lund, Sweden ESS during the 2 nd half of Source: ESS website 07/02/2017 NFF seminars 58

59 Modern spallation neutron sources European Spallation Source, Lund, Sweden 2.86 ms long proton pulse 2 GeV 14 Hz 5 MW of average beam power 4% duty cycle on target Source: ESS website 07/02/2017 NFF seminars 59

60 Modern spallation neutron sources Other types spallation neutron sources Steady state spallation source SINQ at the Paul Scherrer Institute in Switzerland Provides thermal and cold neutrons Except the neutron releasing process it resembles closely a medium flux research reactor Low energy neutron source E.g. LENS at Indiana University, USA Pulsed neutron source Low energy Be coupled with a high-current, variable-pulse-width proton accelerator SINQ target station (Courtesy PSI website) 07/02/2017 NFF seminars 60

61 Alternative spallation neutron sources Alternative low-energy spallation neutron sources Electron Linac e- bremsstrahlung photo-neutron sources Heavy element targets preferred For W on the plateau, the energy deposited in the target per neutron produced is E Y(E) 2800 MeV/neutron Low energy neutron sources Advantages: low cost, minimal shielding, cold moderator easy, easily adaptable for testing, development and training Disadvantages: Modest flux (long experiment times), only few neutron beams 07/02/2017 NFF seminars 61

62 Thank you! I N S T I T U T L A U E L A N G E V I N I N S T I T U T M A X V O N L A U E - P A U L L A N G E V I N 62