Experiments on the AcceleratorDriven System ADS with 100

Experiments on the Accelerator-Driven System (ADS) with 100 Me. V protons at the Kyoto University Critical Assembly C. H. Pyeon (Research Reactor Institute, Kyoto University, Japan) C. H. Pyeon, Kyoto Univ. 1

Self-introduction 1. Cheolho Pyeon (2 nd generation of KOR-JPN) -> Born and Grown up in Japan 2. Home town in Korea – Yuiseong, Kyeong Buk 3. Address in Japan – Kobe (Big harbor city) 4. Education (BE, ME and Ph. D. ) in Japan 5. Major – Nuclear reactor physics, Nuclear education, Radiation detection 5. Hobby – Soccer (Playing manager) and Trekking C. H. Pyeon, Kyoto Univ. 2

Road Map of ADS Program in KURRI ADS for Incineration Commercial ADS Demonstration ADS Scientific Res. Neutron Source ADS 10 yrs. After ? R&D for Accelerator R&D for Subcritical Reactor R&D for Material R&D for Heat Removal Evaluation of Feasibility 5 yrs. after Present stage (KURRI) Prototype ADS 15 yrs. After ? Energy Amplifier System R&D for Fuel Cycle Technology R&D for Reactor Safety C. H. Pyeon, Kyoto Univ. 3

Brief History of ADS R&D Ø Composition of ADS in Kyoto Univ. (KUCA + 100 Me. V protons) - Kyoto University Critical Assembly (KUCA) - Fixed-Field Alternating Gradient (FFAG) accelerator Ø Basic experiments: 235 U-loaded core with 14 Me. V neutrons - IAEA benchmark problems C. H. Pyeon et al. , J. Nucl. Sci. Technol. , 44, 1368 (2007). C. H. Pyeon et al. , J. Nucl. Sci. Technol. , 45, 1171 (2008). C. H. Pyeon et al. , J. Nucl. Sci. Technol. , 46, 965 (2009). C. H. Pyeon et al. , Ann. Nucl. Energy, 40, 229 (2012). Ø World’s first injection of 100 Me. V proton beams into the KUCA cores (235 U- and/or 232 Th-loaded cores) C. H. Pyeon et al. , J. Nucl. Sci. Technol. , 46, 1091 (2009). C. H. Pyeon et al. , J. Nucl. Sci. Technol. , 47, 1090 (2010). , C. H. Pyeon et al. , Ann. Nucl. Energy, 38, 2298 (2011). J. Y. Lim et al. , Sci. Technol. Nucl. Install. , 2012, 9 (2012). C. H. Pyeon et al. , Nucl. Eng. Technol. , (2012). [in print] C. H. Pyeon, Kyoto Univ. 4

Background u. ADS Research and Development for producing energy and for transmuting minor actinides (MA) and long-lived fission products (LLFP) u. World’s first injection of 100 Me. V protons onto tungsten (W) target at KUCA on 4 th Mar. 2009 u 232 Th-loaded ADS experiments with 100 Me. V protons on 3 rd Mar. 2010 u. Successive 235 U- and 232 Th-loaded ADS experiments with 100 Me. V protons on Feb. 2011 and 2012 C. H. Pyeon, Kyoto Univ. 5

ADS composition 11 Me. V, 5 m. A (Max. ) Electron LINAC H- Charge convert H- -> H+ 100 Me. V H+ Proton beam current 1 n. A Main ring (FFAG acc. ) KUCA Max. power : 100 W Yield : 1 × 1011 1/s C. H. Pyeon, Kyoto Univ. 6

ADS composition in KUCA FFAG accelerator Me. V 0 0 1 on prot m bea line KUCA A-core C. H. Pyeon, Kyoto Univ. 7

KUCA core (Solid-moderated core) - KUCA core A solid-moderated and -reflected core Fig. KUCA core Fig. Image of KUCA core and fuel assembly loaded C. H. Pyeon, Kyoto Univ. 8

Key Parameters in ADS Reactor core u. Neutron spectrum - Soft or Hard: Thermal or Fast u. Subcriticality - Near critical, Shallow or Deep External source u. Neutron spectrum - High-energy neutrons (ex. 14 Me. V neutrons vs. 100 Me. V protons) u. Beam specification - Energy, Intensity, Beam spot, Beam repetition rate, Beam width C. H. Pyeon, Kyoto Univ. 9

First Injection of Spallation Neutrons - 2009 Fig. Time series of neutrons Spallation neutrons from target Delayed neutrons in core Neutron multiplication by spallation neutrons generated by protons C. H. Pyeon, Kyoto Univ. 10

Proton Beam Characteristics - 2009 Top Target Bottom Peak value - 14 % -8% -9% 7 cm 14 cm 21 cm Fig. Results of Gafchromic films varying the distance from target (80 mmf & 10 mmt) Fig. Results of scanning data of Gafchromic films varying the distance from target C. H. Pyeon, Kyoto Univ. 11

Reaction Rates - 2009 Reflector Fuel region Fig. Side view of the KUCA A-core Fig. Reaction rate distribution by In wire Reaction rate distribution ü Measure 115 In (n, g) 116 m. In (Exp. error: Too large) ü Effects on subcriticality and core configuration C. H. Pyeon, Kyoto Univ. 12

Proton Beams – 2009 vs. 2010 Top Mar. 2009 Spec. Mar. 2010 3 p. A Intensity 30 p. A 100 Me. V Energy 100 Me. V 1. 0 E+06 Neutron Yield (1/s) 1. 0 E+07 Target Bottom Top Target Bottom Improved Beam shape and Intensity at the target C. H. Pyeon, Kyoto Univ. 13

232 Th-loaded ADS Experiments - 2010 Ø FFAG Accelerator - Energy: 100 Me. V - Intensity: 30 p. A - Repetition rate: 30 Hz - Neutrons: 1. 0 E+07 1/s (at target) - W (tungsten) target: 80 mm diameter and 10 mm thick Ø KUCA core using Th - Thorium fuel only - Thorium fuel and Graphite Objective: Measure thorium fission reactions by spallation neutrons C. H. Pyeon, Kyoto Univ. 14

Exp. Settings of 232 Th-loaded Experimental settings u u Upper In foils (10*10*1 mm 3 50*50*1 mm 3) Protons u u u ADS Exp. - 2010 Fuel size: 5× 5 Volume: 27. 65× 25. 40 cm 3 keff = 0. 03250 (ENDF/B-VII. 0) 232 Th(n, f ) threshold: 1. 5 Me. V 115 In(n, n’)115 m. In threshold: 0. 35 Me. V W target (80 mmf & 10 mmt) Thorium core W target Protons Lower Neutrons C. H. Pyeon, Kyoto Univ. 15

232 Th-loaded Fuel size: 7× 7 u Core volume: 38. 71 x 38. 71 x 30. 48 cm 3 (2. 4 times than Th-core) u keff = 0. 02399 (ENDF/B-VII. 0) Upper 上部 2. 54 cm u 30. 5 cm Unit cell ADS with Graphite - 2010 Fig. Neutron spectra of 232 Th-loaded cores in ADS exp. 下部 Lower C. H. Pyeon, Kyoto Univ. 16

Static exp. in 232 Th-loaded ADS - 2010 Table Ratio of measured reaction rates normalized by target information (In foil) Distance (cm) Ratio (Th. Gr/Th) 0 1. 14± 0. 03 5. 53 1. 13± 0. 03 11. 06 1. 15± 0. 05 16. 59 1. 39± 0. 08 22. 12 1. 56± 0. 11 Fig. Comparison of measured reaction rates in 232 Th-loaded ADS experiments Confirmation of increasing reaction rates of 50% at max. in the core => Decreasing the leakage effect by the large core size C. H. Pyeon, Kyoto Univ. 17

MCNPX (ENDF/B-VII) Analyses - 2010 n 232 Th fission reactions by Monte Carlo approach Solution n n Convert Th fission reactions to capture reactions (“fission turnoff” option) Code: MCNPX-2. 5. 0 Library: JENDL High Energy 232 Th: ENDF/B-VII. 0 Finally, Fig. Comparison of measured and calculated reaction rates in 232 Th-loaded core Confirmation of 232 Th fission reactions generated by spallation neutrons (using “fission turnoff” option in MCNPX) C. H. Pyeon, Kyoto Univ. 18

Kinetic Exp. in 232 Th-loaded ADS - 2010 #2 W target #4 Important knowledge #3 Fig. Neutron density of time evolution by Pulsed neutron method in Th-loaded core Ø No deduction of Subcriticality (--> Very large neutron decay constant) Ø Further efforts for a variety of ADS options using fuels (Th, HEU, NU) and moderators (Poly. , Al, Graphite and Be) C. H. Pyeon, Kyoto Univ. 19

Additional Exp. in 232 Th-ADS - 2011 Ø FFAG Accelerator - Energy: 100 Me. V - Intensity: 300 p. A Repetition rate: 30 Hz Neutrons: 1. 0 E+08 1/s (at target) W (tungsten) target: 80 mm diameter and 10 mm thick Drawbacks (Beam configuration and characteristics) - Changeable beams -> No fix of beam configuration every year - Unstable beams -> No fix of time evolution parameters due to charge-up beams - Available for static experiments only, not for kinetic experiments Ø KUCA core - 232 Th-loaded cores - Thorium fuel and several moderators -> Spectrum change C. H. Pyeon, Kyoto Univ. 20

Conversion of Thorium fuel cycle - 2011 - Capture reactions General conversion concept - Fission reactions However, as a first step, attention should be paid to the following: - Capture reactions (by thermal neutrons moderated from high-energy neutrons) - Fission reactions (by high-energy neutrons) (Threshold of 2 Me. V neutrons) C. H. Pyeon, Kyoto Univ. 21

232 Th-ADS W target core region Fig. Core configuration of with 100 Me. V protons - 2011 Reflector region 232 Th-loaded core Fig. Comparison of measured 115 In (n, g)116 m. In reaction rates in 232 Th-loaded cores Effect of neutron spectrum on thorium capture reactions for high-energy neutrons C. H. Pyeon, Kyoto Univ. 22

Comparative study on 232 Th-ADS - 2011 Fig. Core configuration of 232 Th-loaded cores Fig. Comparison of measured 115 In (n, g)116 m. In reaction rates in 232 Th-loaded cores - Effects on thorium capture reactions Ø External sources 14 Me. V neutrons vs. 100 Me. V protons Ø Neutron spectrum Fig. Th-PE cells Fig. Th-Be cells C. H. Pyeon, Kyoto Univ. 23

Latest ADS exp. - 2012 Ø FFAG Accelerator - Energy: 100 Me. V - Intensity: Less than 10 p. A Repetition rate: 30 Hz Neutrons: 1. 0 E+06 1/s (at target) W (tungsten) target: 80 mm diameter and 10 mm thick Drawbacks (Beam configuration and characteristics) - Changeable beams -> No fix of beam configuration every year - No highly-intensity beams -> Why? - Available for limited static and kinetic experiments Ø KUCA core – 235 U- and 232 Th-loaded cores - Uranium fuel and polyethylene - Thorium fuel and several moderators C. H. Pyeon, Kyoto Univ. 24

Pulsed Neutron Method (232 Th-ADS) - 2012 Fig. Results in Th-HEU-PE with 100 Me. V protons Fig. Core configuration of 232 Th-Poly. Cores (100 Me. V protons) Table Results in keff (3 He #3; Area ratio method) Cal. Exp. Core MCNPX 100 Me. V Protons 14 Me. V Neutrons Th-HEU-PE 0. 5876 0. 7346 0. 6577 beff = 8. 491 E-03; SRAC-CITATION 107 -G, 3 -D a = 5065 ± 28 (100 Me. V Protons) Fig. Results in Th-PE with 14 Me. V neutrons 5288 ± 13 (14 Me. V Neutrons) C. H. Pyeon, Kyoto Univ. 25

Multi-target study in 235 U-ADS - 2012 Fig. Neutron spectra (W vs. W+Be) Fig. Core configuration of 235 U-Poly. Cores (100 Me. V protons) Fig. In reaction rates (W vs. W+Be) C. H. Pyeon, Kyoto Univ. 26

Summary u ADS project (Kart & Lab. project) in Kyoto Univ. - Energy amplifier system using ADS with high-energy protons u World’s first injection of high-energy protons on Mar. 2009 - 235 U-loaded ADS exp. with 100 Me. V protons u 232 Th-loaded ADS exp. with 100 Me. V protons on Mar. 2010 - Static experiments ・ 232 Th fission reactions by MCNPX with ENDF/B-VII - Kinetic experiments ・No deduction of subcriticality due to a very large neutron decay - Further efforts for a variety of ADS options using fuels (Th, HEU and NU) and moderators (Poly. , Al, Gr. and Be) Future works (to be planned) l Experiments on the conversion ratio of Thorium capture and fission l Nuclear transmutation study using 237 Np and 241 Am (foil or detector) C. H. Pyeon, Kyoto Univ. 27

Publications u. Cancer center (2007 and 2008) - C. H. Pyeon, H. Shiga, K. Abe et al. , “Reaction Rate Analysis of Nuclear Spallation Reactions Generated by 150, 190 and 235 Me. V Protons, ” J. Nucl. Sci. Technol. , 47, 1090 (2010). u 2009 - C. H. Pyeon, J. Y. Lim, T. Misawa and S. Shiroya, “Current Status of Accelerator-Driven System with High-Energy Protons in Kyoto University Critical Assembly, ” Trans. Am. Nucl. Soc. , 101, 25 (2009). - C. H. Pyeon, T. Misawa, J. Y. Lim et al. , “First Injection of Spallation Neutrons Generated by High-Energy Protons into the Kyoto University Critical Assembly, ” J. Nucl. Sci. Technol. , 46, 1091 (2009). - H. Shahbunder, C. H. Pyeon, T. Misawa et al. , “Effects of Neutron Spectrum and External Neutron Source on Neutron Multiplication Parameters in Accelerator-Driven System, ” Ann. Nucl. Energy, 37, 1785 (2010). u 2010 - C. H. Pyeon, J. Y. Lim and T. Misawa, “Experiments on Injection of Spallation Neutrons by 100 Me. V Protons into the Kyoto University Critical Assembly, ” Trans. Am. Nucl. Soc. , 103, 21 (2010). - C. H. Pyeon, J. Y. Lim, Y. Takemoto et al. , “Preliminary Study on the Thorium-Loaded Accelerator-Driven System with 100 Me. V Protons at the Kyoto University Critical Assembly, ” Ann. Nucl. Energy, 38, 2298 (2011). - C. H. Pyeon, J. Y. Lim, T. Yagi and T. Misawa, “Reaction Rate Analyses in the Thorium-Loaded Accelerator-Driven System at the Kyoto University Critical Assembly, ” Trans. Am. Nucl. Soc. , 105, 792 (2011) - C. H. Pyeon, T. Azuma, Y. Takemoto et al. , “Experimental Analyses of External Neutron Source Generated by 100 Me. V Protons at the Kyoto University Critical Assembly, ” Nucl. Eng. Technol. , (2012). [in print] u 2011 - J. Y. Lim, C. H. Pyeon, T. Yagi et al. , “Subcritical Multiplication Parameters of the Accelerator-Driven System with 100 Me. V Protons at the Kyoto University Critical Assembly, ” Sci. Technol. Nucl. Install. , 2012, ID: 395878, 9 pages, (2012). u. Cancer center (2012) -Y. Takahashi, T. Azuma, T. Nishio et al. , “Conceptual Design of Multi-Target for the Accelerator-Driven System Experiments with 100 Me. V Protons, ” Ann. Nucl. Energy, (2012). [in print] u 2012 - Number of two papers prepared (1. Comparative 232 Th-ADS; 2. Multi-target in 235 U-ADS)C. H. Pyeon, Kyoto Univ. 28