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different fuel enrichment were proposed to assess the different depletion trend in the each case. The feasibility of the ultra-long cycle operation was firstly confirmed by the multiplication factor trend and its reactivity swing for each case. Through the additional analysis with the conversion ratio, power distribution, mass flow, neutron balance, and the neutron kinetics and reactivity parameters, the core characteristics of each case was evaluated so that it is prepared to optimize the final core design by some combination of the depletion cases. It was observed that the long life time with a large reactivity swing of the onion zoning case, the breeding potential but the subcritical state of the axial-dual breeding case, and the smaller reactivity swing than any other cases of the radial breeding case. From a sensitivity study of the enrichment and the amount of blanket in each breeding cases by some combinations of them, an optimized breed-and-burn model was drawn to be applied for SM-SFR. It has been confirmed that the final optimized core design operates 28.5 years with the reactivity swing of less than 500 pcm.
The core has blanket region in its second and third radial rings with the 80 cm height and the enrichment of LEU region is 13.2 %. It breeds from the periphery to the center of the core mainly in radial direction and the conversion ratio is near 0.75 and it increases to 0.85 as the active core moves to the blanket region. The fuel material mass flow and the power distribution show that the breed-and-burn is achieved well by the fuel conversion in the driver fuel and the blanket respectively. As burnup proceeds and the active core moves to inner region of the core, the number of neutron per fissile absorption, eta, increases while the neutron leakage and the delayed neutron fraction decrease, which leads the increase of the sodium void worth and the control rod worth. It has also been confirmed that loading the PWR spent fuel in the blanket is feasible to have the comparable cycle length of NU blanket core with the reduction of the zirconium fraction to 7 wt%.
To ensure the inherent safety of the newly developed SM-SFR, the safety analysis was performed. For the first, control rod system was optimized by the configuration change of the control rods for both primary and secondary systems and the shutdown margin was calculated through the reactivity worth available and the maximum requirement. Furthermore, europium oxide (Eu2O3) was proposed for the primary control rod material for that the physical efficiency of neutron absorption does not actually decrease under long-term reactor irradiation due to the gadolinium production so it is favorable especially for the ultra-long cycle reactor like SM-SFR.
To assess the inherent safety in any operation state, the quasi-static reactivity balance analysis was performed for the ATWS events to evaluate in the neutronics point of view. The integral reactivity parameters are all negative, and the calculation result of the quasi-static reactivity for the three ATWS events satisfies each of the criteria. The inherent safety of the core was assessed by the transient analysis also using a thermal-hydraulic and neutronics analysis code for power and flow transient. For the ULOF, ULOHS, and UTOP events, the core has been confirmed that it has inherent safety features as analyzed in the neutronics balance analysis.
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REFERENCES
1. Richard E. Smalley, “Future Global Energy Prosperity: The Terawatt Challenge,” MRS bulletin, 30, 412-417, June (2005).
2. The Shift Project Data Portal (http://www.tsp-data-portal.org/).
3. www.iaea.org/INPRO.
4. A Technology Roadmap for Generation IV Nuclear Energy Systems, GIF-002.
5. Gen-IV International Forum R&D Outlook for Generation IV Nuclear Energy Systems (2009).
6. IAEA, Status of Small and Medium Sized Reactor Designs, A supplement to the IAEA Advanced Reactors Information System (ARIS), http://aris.iaea.org, September (2012).
7. KEIT PD issue report, 14-9, September (2014).
8. H. Shim et al., “McCARD: Monte Carlo Code for Advanced Reactor Design and Analysis,” Nucl.
Eng. Technol., 44(2), 161-176 (2012).
9. International handbook of evaluated criticality safety benchmark experiments.
NEA/NSC/DOC(95)03, OECD Nuclear Energy Agency (2006).
10. M. Edenius and B.H. Forrsen, “CASMO-3: a fuel assembly burnup program user’s manual.
Studsvik/NFA-89-3, Revision 2, Studsvik AB (1992).
11. R. J. J. Stamm’ler, “HELIOS Methods,” Studsvik Scandpower (2002).
12. K. Okumura et al., “Validation of a continuous-energy Monte Carlo burn-up code MVP-BURN and its application to analysis of post irradiation experiment,” Journal of Nuclear Science and Technology, 37(2), 128-138 (2000).
13. C. H. Lee et al., MC2-3: multi-group cross section generation code for fast reactor analysis, NE- 11-41, (2011).
14. R. E. Alcouffe et al., DANTSYS: a diffusion accelerated neutron particle transport code system, LA-12969-M, (1995).
15. R. D. Lawrence, The DIF-3D nodal neutronics option for two- and three-dimensional diffusion- theory calculations in hexagonal geometry, ANL-83-1, (1983).
16. A. P. Olson, A users guide for the REBUS-PC code, version 1.4, Argonne National Laboratory at Lemont, IL, (2001).
17. M. A. Smith, C. Adams, W. S. Yang, and E. E. Lewis. VARI3D & PERSENT: perturbation and sensitivity analysis, NE-13-8, (2013).
18. Alan E. Waltar, Donald R. Todd, Pavel V. Tsvetkov, Fast Spectrum Reactors, Springer (2012).
19. D. C. Wade and Y. I. Chang, “The Integral Fast Reactor Concept: Physics of Operation and Safety,”
Nuclear Technology, 100, 507-524 (1988).
20. J. E. Cahalan, T. H. Fanning, The SAS4A/SASSYS-1 Safety Analysis Code System, ANL/NE- 12/4 (2012).
117
21. K. M. Goff, M. F. Simpson, Dry Processing of Used Nuclear Fuel, Global 2009, Paris, France, September 6-11 (2009).
22. A. G. Croff, A User’s Manual for the ORIGEN2 Computer Code, PRNL/TM-7175.
23. T. Tak and D. Lee, “Design of ultra-long cycle fast reactor with PWR spent fuel,” Transactions of Korean Nuclear Society Spring Meeting, Jeju, Korea, May 17–18 (2012).
24. T. Tak, D. Lee, T. K. Kim, “Core design study of ultra-long cycle fast reactor concept,”
International Conference of Fast Reactors and Related Fuel Cycle (FR13), Paris, France, March 4- 7 (2013).
25. H. Sekimoto, K. Ryu, Y. Yoshimura, “CANDLE: the new burnup strategy,” Nuclear Science and Engineering, 139, 306-317 (2001).
26. Hejzlar P et al., “TerraPower, LLC traveling wave reactor development program overview,”
Nuclear Engineering and Technology, 45(6), 731-744 (2013).
27. S. G. Hong, E. Green, Y. I. Kim, “The encapsulated nuclear heat source (ENHS) reactor core design,” Nucl. Technol., 149(1), 22-48 (2005).
28. D. Hartanto and Y. Kim, “Alternative reflectors for a compact sodium-cooled breed-and-burn fast reactor,” Annals of Nuclear Energy, 76, 113-124 (2015).
29. HaeLee Hyun and Ser Gi Hong, “A sodium-cooled ultra-long-life reactor core having improved inherent safety with new driver-blanket burning strategy,” International Journal of Hydrogen Energy, 41, 7082-7093, (2016).
30. Ser Gi Hong, HaeLee Hyun, and Wuseung You, “Core design options of an ultra-long-cycle sodium cooled reactor with effective use of PWR spent fuel for sustainable energy supply,”
International Journal of Energy Research, DOI: 10.1002/er.3677, (2016).
31. T. Tak, D. Lee, and T. K. Kim, “Design of ultralong-cycle fast reactor employing breed-and-burn strategy,” Nucl. Technol., 183 (3), 427-435 (2013).
32. N. Takaki, “Core Design and Deployment Strategy of Heavy Water Cooled Sustainable Thorium Reactor,” Sustainability, 4(8), 1933-1945 (2012).
33. Nuclear Science and Technology for Ceramists, Proceedings of the American Ceramic Society Symposium, Washington, D. C., April 7-12, (1966).
34. Janis 4.0, OECD NEA
35. Y. I. Chang, “The integral fast reactor,” Nuclear Technology, 88, 129-138 (1989).
36. Y. I. Chang, “Technical Rationale for Metal Fuel in Fast Reactors, Nuclear Engineering and Technology,” 39(3), (2007).
37. D. Okrent, “Neutron Physics Considerations in Large Fast Breeder Reactors,” Power Reactor Tech., 7 (1964).
38. Keung Koo Kim, Wonjae Lee, Shun Choi, Hark Rho Kim and Jaejoo Ha, “SMART: The First Licensed Advanced Integral Reactor,” Journal of Energy and Power Engineering, 8, 94-102 (2014).
118
39. T. Tak et al., “Optimization study of ultra-long cycle fast reactor core concept,” Annals of Nuclear Energy, 73, 145–161 (2014).
40. T. K. Kim, C. Grandy, and R. N. Hill, “A 100MWe advanced sodium-cooled fast reactor core concept,” PHYSOR 2012, Knoxville, TN, USA, April 15-20 (2012).
41. H. Sekimoto, S. Miyashita, “Startup of ‘‘Candle’’ burnup in fast reactor from enriched uranium core,” Energy Conversion and Management, 47, 2772–2780 (2006).
42. M. Yan and H. Sekimoto, “Design research of small long life CANDLE fast reactor,” Annals of Nuclear Energy, 35, 18–36 (2008).
43. J. Choe, T Tak, Y Jeong, D Lee, T. K. Kim, “The impact of thorium blanket on long-life fast reactor core performance characteristics,” ANUP2014, Jeju Island, Korea, November 9-12 (2014).
44. N. Ueda et al., “Sodium cooled small fast long-life reactor 4S,” Progress in Nuclear Energy, 47, 222-230 (2005).
45. SUPER-SAFE, SMALL AND SIMPLE REACTOR (4S, TOSHIBA DESIGN), Toshiba Corporation and Central Research Institute of Electric Power Industry (CRIEPI), Japan (2013).
46. Minato A et al. Advanced 4S (super safe, small and simple) LMR, IAEA Tecdoc., ISSN 1011-4289 (2000).
47. Y. I. Chang, M. Konomura, P. L. Pinto, “A case for small modular fast reactor,” Journal of Nuclear Science and Technology, 44, 264-269 (2007).
48. Planchon HP, Singer RM, Mohr D, Feldman EE, Chang LK, Betten PR, “The experimental breeder reactor ii inherent shutdown and heat removal tests – results and analysis,” Nuclear Engineering and Design, 91, 287-296 (1986).
49. Baker RB, Bard FE, Leggett RD, Pitner AL. “Status of fuel, blanket, and absorber testing in the fast flux test facility,” Journal of Nuclear Materials, 204, 109-118 (1993).
50. F. Heidet, T. K. Kim, C. Grandy, Feasibility study on AFR-100 fuel conversion from uranium- based fuel to thorium-based fuel, ANL-ARC-227 (2012).
51. Carlo Fiorina, Fausto Franceschini, Matt Memmott, Safety Aspects of Thorium Fuel in Sodium- Cooled Fast Reactors, FR13, Paris, France, March 4-7 (2013).
52. W. Yang, “Fast reactor physics and computational methods,” Nucl Eng Technol; 44(2), 177-198 (2012).
53. H. Blank, “Specification and characterization of dense fuels for liquid metal cooled fast breeder reactors,” Journal of Nuclear Materials, 153, 171-177 (1988).
54. Compilation courtesy of Jeremy Caruso (2010).
55. Uddharan Basak, Joint ICTP/IAEA School on Physics and Technology of Fast Reactors Systems (2009).
56. T. K. Kim, C. Grandy, R. N. Hill, “Carbide and nitride fuels for advanced burner reactor,” FR09, Kyoto, Japan, December 7-11 (2009).
119
57. S. Zaki, H. Sekimoto, “Accident analysis of lead or lead-bismuth cooled small safe long-life fast reactor using metallic or nitride fuel,” Nuclear Engineering and Design, 162, 205-222 (1996).
58. S. Yoshihiko, “Selection of sodium coolant for fast reactors in the US, France and Japan,” Nuclear Engineering and Design, 254, 194-217 (2013).
59. T. H. Fanning, Sodium as a fast reactor, U.S. Nuclear Regulatory Commission (2007).
60. I, Silverman et al., “High heat-flux accelerator targets: cooling with liquid metal jet impingement,”
International Journal of Heat and Mass Transfer, 49, 2782-2792 (2006).
61. T. Sawada et al., “Gallium-cooled liquid metallic-fueled fast reactor,” Progress in Nuclear Energy, 37, 313-319 (2000).
62. S. V. Stankus et al., “The density and thermal expansion of eutectic alloys of lead with bismuth and lithium in condensed state,” Journal of Physics, Conference Series 98 (2008).
63. Walters L, Lambert J, Natesan K, Wright A, Yacout A, Hayes S, Porter D, Garner F, Ott L, Denman M. Sodium fast reactor fuels and materials: research needs, Sand report (2011).
64. Dr. Christian LATGE, Sodium Fast Reactors Systems and Components, IAEA Education &
Training Seminar on Fast Reactor Science and Technology, CNEA Bariloche, Argentina, October (2012).
65. Small Modular Fast Reactor Design Description, Joint effort by Argonne National Laboratory &
Commissriat àl’Energie Atomique & Japan Nuclear Cycle Development Institute, ANL-SMFR-1, TR (2005).
66. Xu Mi, “Development of Fast Breeder Reactor and Experiment Fast Reactor in China,” Nuclear Power Engineering, 21, No.1, (2000).
67. S. M. Lee, S. Govindarajan, R. Indira, T.M. John, P. Mohanakrishnan, R. Shankar Singh, Sb. Bhoje,
“Conceptual Design of PFBR Core,” Indira Gandhi Centre for Atomic Research.
68. T. K. Kim, C. Grandy, “Assessment of Fission Gas Vented Fuel Impact with Advanced Burner Reactor,” PHYSOR 2010, May 9-14 (2010).
69. W. Beck, R. Fousek, J. Kittel, The Irradiation Behavior of High-Burnup Uranium–Plutonium Alloy Prototype Fuel Elements, ANL-7388. Argonne National Laboratory, May (1968).
70. Crawford DC et al., “Fuels for sodium-cooled fast reactors: US perspective,” Journal of Nuclear Material, 371, 202-231 (2007).
71. K. R. Birney, A. Van Echo, United States Experience with LMFBR Control Material Selection, Fuel and Core Division, Office of Breeder Technology Projects, United States Department of Energy, Washington D. C., United States of America.
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ACKNOWLEDGEMENTS
Hallelujah, Jehovah Shammah.
부족함에 부끄러움이 앞서지만, 지금까지 함께하여 주신 분들에 대한 감사는 또한 앞으로의 약속이기에, 짧은 말로써 다 담아낼 수 없는 마음을 표현하고자 합니다.
가장 먼저, 다른 학과를 졸업하고 앳된 열의만 있었던 저를 첫 제자로 받아주셔서 많이 고생하신 지도교수님 이덕중 교수님께 감사 드립니다. 교수님께는 정말 많은 것을 배우고 많은 특혜를 받았기에 이렇게 짧은 인사가 민망할 따름입니다. 지도교수로서, 선생님으로서, 연구선배로서, 그리고 인생선배로서 저에게 보여주신 많은 모습들은 제게 평생의 도전 과제입니다. 끊임없이 발전하는 모습을 보여드리는 것만이 교수님께 보답할 길임을 명심하여 게으르지 않고 정진하는 모습 보여드리도록 하겠습니다. 교수님, 감사합니다.
특별히, 먼 곳에서 바쁘신 와중에도 본인의 그 오랜 경험과 세계적인 노하우를 전수하여 주시기 위해 많은 시간과 노력을 할애하여주신 김택겸 박사님, 많은 감사를 드립니다. 저도 반드시 박사님과 같이 후배들에게 좋은 것을 스스럼 없이 베풀 수 있는 선배가 되도록 노력하겠습니다.
‘개국공신’CORE Lab.의 원로들 현석이, 수영이, 치동이, 지원이에게 특별한 감사를 표합니다. 정말 말 그대로 ‘동고동락’하며 오랜 시간 함께 해온 너희들에겐 선배로서 마땅히 해주었어야 할 것들보다 너희들 각자가 짊어진 짐들이 많았으니 미안함과 아쉬움이 앞선다.
이제는 각자가 각 과제의 리더가 되어 후배들을 이끌고 있는 모습을 보니 졸업 후 각자의 모습에 큰 기대가 되고 벌써부터 자랑스럽다. 이제 원로가 될 민용이와 이하 원경이, 기호, 한주, 진수, 상걸이, 윤기, 은이, 재림이, Azamat, Bamidele 모두 작은 일부터 큰 일까지 잘 따라와주어 고맙고, 함께한 시간들이 아주 나에게 소중했음을 꼭 말하고 싶다. Also, I would like to thank Dr.
Peng Zhang, Dr. Youqi Zeng, Dr. Lemaire, Dr. Jiankai Yu, and Dr. khoshahval for their kind advices and sincere helps. Although we talked with different language, I’m sure we had deep conversation as well as technical discussion. 앞으로 우리 실험실에 들어올 성필이 용민이 외 학부생들에게도 우리 실험실의 자부심과 그 만큼의 노력을 부탁합니다. 아쉽지만 우리 실험실에 거쳐갔던 학생들에게도 함께 했던 시간들의 고마움을 표합니다.
처음 유니스트에 왔을 때 하나의 오피스에서 같이 생활했었던 원자력과 선배들 승원이형, 상훈이형, 병진이형, 종진이형, 주앙이형, 성대형, 사라누나, 성만이형, 영락이형, 경준이, 대학원 동기 한이, 이후에 합류한 동한이형, 영진이형, 상일이 모두 감사합니다. 연구실 내 선배가 없던 저에게 마음이 흔들릴 때 마다 이 길을 계속 가게 해주었던 힘이 되어주셨고 큰 의지가 되어주셨습니다. 처음 봤을 땐 학부생 이었지만 지금은 각 실험실에서 후배들을 이끌고 있는 많은 유니스타들에게도 감사와 기대를 표합니다.