Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium

Xiao-Xiao Li; De-Yang Cui; Chun-Yan Zou; Jian-Hui Wu; Xiang-Zhou Cai; Jin-Gen Chen

doi:10.1007/s41365-023-01216-0

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Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium

NUCLEAR ENERGY SCIENCE AND ENGINEERING | Updated：2023-07-18

- Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium
- Nuclear Science and Techniques Vol. 34, Issue 5, Article number: 70(2023)
- Affiliations：
  
  1.Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
  2.CAS Innovative Academy in TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800, China
  3.University of Chinese Academy of Sciences, Beijing 100049, China
- Author bio：
  
  † caixz@sinap.ac.cn
  ‡ chenjg@sinap.ac.cn
- Funds：
  
  Youth Innovation Promotion Association CAS(2022258);National Natural Science Foundation of China(12175300);Young Potential Program of Shanghai Institute of Applied Physics, Chinese Academy of Sciences under Grant(E1550510)
- DOI：10.1007/s41365-023-01216-0
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Xiao-Xiao Li, De-Yang Cui, Chun-Yan Zou, et al. Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium. [J]. Nuclear Science and Techniques 34(5):70(2023)
DOI：

Xiao-Xiao Li, De-Yang Cui, Chun-Yan Zou, et al. Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium. [J]. Nuclear Science and Techniques 34(5):70(2023) DOI： 10.1007/s41365-023-01216-0.

摘要

Abstract

To provide a reliable and comprehensive data reference for core geometry design of graphite-moderated and low-enriched uranium fueled molten salt reactors, the influences of geometric parameters on the temperature coefficient of reactivity (TCR) at an assembly level were characterized. A four-factor formula was introduced to explain how different reactivity coefficients behave in terms of the fuel salt volume fraction and assembly size. The results show that the fuel salt temperature coefficient (FSTC) is always negative owing to a more negative fuel salt density coefficient in the over-moderated region or a more negative Doppler coefficient in the under-moderated region. Depending on the fuel salt channel spacing, the graphite moderator temperature coefficient (MTC) can be negative or positive. Furthermore, an assembly with a smaller fuel salt channel spacing is more likely to exhibit a negative MTC. As the fuel salt volume fraction increases, the negative FSTC first weakens and then increases, owing to the fuel salt density effect gradually weakening from negative to positive feedback and then decreasing. Meanwhile, the MTC weakens as the thermal utilization coefficient caused by the graphite temperature effect deteriorates. Thus, the negative TCR first weakens and then strengthens, mainly because of the change in the fuel salt density coefficient. As the assembly size increases, the magnitude of the FSTC decreases monotonously owing to a monotonously weakened fuel salt Doppler coefficient, whereas the MTC changes from gradually weakened negative feedback to gradually enhanced positive feedback. Then, the negative TCR weakens. Therefore, to achieve a proper negative TCR, particularly a negative MTC, an assembly with a smaller fuel salt channel spacing in the under-moderated region is strongly recommended.

关键词

Keywords

Molten salt reactorTemperature coefficient of reactivityFour-factor formula

references

V. I. Victor, Molten Salt Reactors. Encyclopedia Nucl Energy, 1, 553-568 (2021). doi: 10.1016/B978-0-12-409548-9.12208-0http://doi.org/10.1016/B978-0-12-409548-9.12208-0

N. Taheranpour, A. Talaei, Development of practical method using a Monte Carlo code for evaluation of optimum fuel pitch in a typical VVER-1000 core. Ann. Nucl. Energy 54, 129-133 (2013). doi: 10.1016/j.anucene.2012.10.029http://doi.org/10.1016/j.anucene.2012.10.029

F. Qayyum, M. R. Ali, A. Zahur, et al., Improvements in methodology to determine feedback reactivity coefficients. Nucl. Sci. Tech. 30, 63 (2019). doi: 10.1007/s41365-019-0588-0http://doi.org/10.1007/s41365-019-0588-0

S. H. Yu, Y. F. Liu, P. Yang, et al., Neutronics analysis for MSR cell with different fuel salt channel geometries. Nucl. Sci. Tech. 32(1), 9 (2019). doi: 10.1007/s41365-020-00844-0http://doi.org/10.1007/s41365-020-00844-0

A. Rykhlevskii, J. W. Bae, K. D. Huff, Modeling and simulation of online reprocessing in the thorium-fueled molten salt breeder reactor. Ann. Nucl. Energy 128, 366-379 (2019). doi: 10.1016/j.anucene.2019.01.030http://doi.org/10.1016/j.anucene.2019.01.030

D.Y. Cui, X.X. Li, Y. Dai et al., An improved core design of a 50 kWth heat pipe cooled micro Molten Salt Reactor (micro-MSR). Prog. Nucl. Energy 151, 104326 (2022). doi: 10.1016/j.pnucene.2022.104326http://doi.org/10.1016/j.pnucene.2022.104326

D.Y. Cui, S.P Xia, X.X. Li et al., Transition toward thorium fuel cycle in a molten salt reactor by using plutonium. Nucl. Sci. Tech. 28(10), 152 (2017). doi: 10.1007/s41365-017-0303-yhttp://doi.org/10.1007/s41365-017-0303-y

G.C. Li, P. Cong, C.G. Yu, et al., Optimization of Th-U fuel breeding based on a single-fluid double-zone thorium molten salt reactor. Prog. Nucl. Energy 108, 144-151 (2018). doi: http://doi.org/

C.Y. Zou, C.G. Yu, J.H. Wu, et al., Ameliorating the positive temperature feedback coefficient for an MSR fueled with transuranic elements. Ann. Nucl. Energy 160(15), 108325 (2021). doi: 10.1016/j.anucene.2021.108325http://doi.org/10.1016/j.anucene.2021.108325

J.H. Wu, J.G. Chen, X.Z. Kang et al., A novel concept for a molten salt reactor moderated by heavy water. Ann. Nucl. Energy 132, 391-403 (2019). doi: 10.1016/j.anucene.2019.04.043http://doi.org/10.1016/j.anucene.2019.04.043

L. Mathieu, D. Heuer, R. Brissot et al., The thorium molten salt reactor: Moving on from the MSBR. Prog. Nucl. Energy 48(7), 664-679 (2006). doi: 10.1016/j.pnucene.2006.07.005http://doi.org/10.1016/j.pnucene.2006.07.005

S. Q. Jaradat, A. B. Alajo, Studies on the liquid fluoride thorium reactor: Comparative neutronics analysis of MCNP6 code with SRAC95 reactor analysis code based on FUJI-U3-(0). Nucl. Eng. Des. 314, 251-255 (2017). doi: 10.1016/j.nucengdes.2017.02.013http://doi.org/10.1016/j.nucengdes.2017.02.013

L. Mathieu, D. Heuer, E. Merle-Lucotte et al., Possible configurations for the thorium molten salt reactor and advantages of the fast nonmoderated version. Nucl. Sci. Eng. 161(1), 78-89 (2009). doi: 10.13182/NSE07-49http://doi.org/10.13182/NSE07-49

J. Křepel, B. Hombourger, C. Fiorina, et al., Fuel cycle advantages and dynamics features of liquid fueled MSR. Ann. Nucl. Energy 64, 380-397 (2014). doi: 10.1016/j.anucene.2013.08.007http://doi.org/10.1016/j.anucene.2013.08.007

C.Y. Zou, X.Z. Cai, D.Z. Jiang, et al., Optimization of temperature coefficient and breeding ratio for a graphite-moderated molten salt reactor. Nucl. Eng. Des. 281, 114-120 (2015). doi: 10.1016/j.nucengdes.2014.11.022http://doi.org/10.1016/j.nucengdes.2014.11.022

C.N.A.C.Z. Bahri, W.M. Al-Areqi, M.I.F.M. Ruf et al., Characteristic of molten fluoride salt system LiF-BeF2 (Flibe) and LiF-NaF-KF (Flinak) as coolant and fuel carrier in molten salt reactor (MSR). AIP Conference Proceedings 1799, 040008 (2017). doi: 10.1063/1.4972932http://doi.org/10.1063/1.4972932

B. Hombourger, J. Křepel, A. Pautz, Breed-and-burn fuel cycle in molten salt reactors. EPJ Nucl. Sci. Technol. 5, 15 (2019). doi: 10.1051/epjn/2019026http://doi.org/10.1051/epjn/2019026

X.X. Li, Y.W. Ma, C.G. Yu et al., Effects of fuel salt composition on fuel salt temperature coefficient(FSTC) for an under-moderated molten salt reactor(MSR). Nuclear Science and Techniques, 29(8), 110 (2018). doi: 10.1007/s41365-018-0458-1http://doi.org/10.1007/s41365-018-0458-1

X.X. Li, D.Y. Cui, Y.W. Ma et al., Influence of 235U enrichment on the moderator temperature coefficient of reactivity in a graphite-moderated molten salt reactor. Nucl. Sci. Tech. 30(11), 166 (2019). doi: 10.1007/s41365-019-0694-zhttp://doi.org/10.1007/s41365-019-0694-z

M.L. Tan, G.F. Zhu, Y. Zou et al., Research on the effect of the heavy nuclei amount on the temperature reactivity coefficient in a small modular molten salt reactor. Nucl. Sci. Tech. 30(9), 140 (2019). doi: 10.1007/s41365-019-0666-3http://doi.org/10.1007/s41365-019-0666-3

B.A. Hombourger, J. Křepel, K. Mikityuk et al., Parametric lattice study of a graphite-moderated Molten Salt Reactor. J. Nucl. Eng. Radiat. Sci. 1(1), 011009 (2015). doi: 10.1115/1.4026401http://doi.org/10.1115/1.4026401

J. Křepel, E. Losa, Self-Sustaining Breeding in Advanced Reactors: Characterization of Selected Reactors. Encyclopedia of Nuclear Energy, 64, 801-819 (2021). doi: 10.1016/B978-0-12-819725-7.00123-9http://doi.org/10.1016/B978-0-12-819725-7.00123-9

Y. Zhu, A.I. Hawari, Thermal neutron scattering cross section of liquid FLiBe. Prog. Nucl. Energy 101(Part C), 468-475, (2017). doi: 10.1016/j.pnucene.2017.03.028http://doi.org/10.1016/j.pnucene.2017.03.028

Y. F. Liu, W. J. Li, R, Yan, et al., Effect of FLiBe thermal neutron scattering on reactivity of molten salt reactor. The European Physical Journal Conferences, 239, 4008 (2020). doi: 10.1051/epjconf/202023914008http://doi.org/10.1051/epjconf/202023914008

C.W. Lau, C. Demaziere, H. Nylen, et al., Improvement of LWR thermal margins by introducing thorium. Progress in Nuclear Energy, 61, 48-56 (2012). doi: 10.1016/j.pnucene.2012.07.004http://doi.org/10.1016/j.pnucene.2012.07.004

R. L. Murray, K. E. Holbert, Nuclear Energy (Eighth Edition) Chapter 16 - Neutron Chain Reactions. Nuclear Energy 291, 305 (2020). doi: 10.1016/B978-0-12-812881-7.00016-2http://doi.org/10.1016/B978-0-12-812881-7.00016-2

X. Wang, R. Macian-Juan, Steady-state reactor physics of the dual fluid reactor concept. International J. Energy Res. 42, 4313-4334 (2018). doi: 10.1002/er.4171http://doi.org/10.1002/er.4171

E. E. Bende, Temperature Reactivity Effects in Pebbles of a High-Temperature Reactor Fueled with Reactor-Grade Plutonium. Nucl. Technol. 131(3), 279-296 (2000). doi: 10.13182/NT00-A3117http://doi.org/10.13182/NT00-A3117

M. Dallas, W. Alexander, C. Ondřej, Lattice optimization for graphite moderated molten salt reactors using low-enriched uranium fuel. Ann. Nucl. Energy 110, 1-10 (2017). doi: 10.1016/j.anucene.2017.06.015http://doi.org/10.1016/j.anucene.2017.06.015

I. I. Al-Qasir, Y.Q. Cheng, J.Y.Y. Lin, et al., Neutron thermalization in nuclear graphite: A modern story of a classic moderator. Ann. Nucl. Energy 161, 108437 (2021). doi: 10.1016/j.anucene.2021.108437http://doi.org/10.1016/j.anucene.2021.108437

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