Optimal core design analysis for a small mobile helium-xenon cooled solid reactor
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摘要: 小型移动式核反应堆电源能为偏远地区、事故应急等场景提供所需的电能和热能,而堆芯的轻量化和小型化是小型移动式核反应堆电源的设计重点。由此,基于前期概念设计,本研究提出了一个高可靠、长寿命的小型氦氙冷却固体核反应堆堆芯设计及其反应性控制方案。首先,在综合考虑反应堆寿命以及热工安全设计等限制条件的基础上,使用蒙特卡罗程序OpenMC进行了堆芯几何优化分析,得到了堆芯质量最小化的设计方案。其次,分析了含可燃毒物的布置优化方案,通过在堆芯靠近反射层附近的燃料棒中添加2%质量分数的可燃毒物Gd2O3,寿期初径向功率峰因子从2.22降低至1.43。最后,基于分层分块滑移反射层的反应性与功率控制方法,提出了反应性线性控制方案,该方案还可以保证事故情况下的反应堆安全。相关结果可为小型移动式核反应堆电源的堆芯设计及反应性控制提供参考。Abstract: Due to electricity needs of scenarios such as remote areas and emergency situations, mobile nuclear power sources with high reliability and long life are needed. A conceptual design scheme of a small mobile helium-xenon cooled solid reactor has been proposed in previous work. This study aims to obtain a lightweight and compact core design and improve the design scheme of sliding reflector segments for reliable reactivity control. Firstly, under the design constraints of reactor life and thermal safety, the core geometry optimization analysis was performed using OpenMC, and a design scheme to obtain minimal mass of core was achieved. Secondly, the study analyzed the influence of burnable poison on power distribution and by adding a 2% mass fraction of Gd2O3 to the fuel rods near the reflector region, the radial power factor was reduced from 2.22 to 1.43 at the beginning of life. Finally, by partitioning the sliding reflector, a linear introduction of reactivity was achieved, and it can also ensure the reactor safety in case of accidents. This study provides a certain reference for the design of small gas-cooled solid reactor.
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表 1 堆芯基准方案基本参数
Table 1. Basic parameters of the core
fuel coolant cladding moderator reflector 235U
enrichment/%fuel
diameter/cmpitch-diameter
ratiocoolant channel
diameter/cmcladding
thickness/cmUC helium-xenon mixture Mo-TZM graphite Be 19.75 1.5 1 0.8 0.05 表 2 堆芯几何参数
Table 2. Geometry parameters of core
core radius/cm core height/cm radial reflector thickness/cm axial reflector thickness/cm 44 104 16 5 表 3 可燃毒物的不同布置方式对功率分布影响
Table 3. Power distribution upon three BP layouts
layout mass fraction/% keff radial power peak factor at BOL no BP − 1.08670 2.22 No.1 0.1 1.07170 2.07 0.5 1.04315 1.79 1.0 1.02381 1.64 2.0 0.99550 1.50 3.0 0.97369 1.43 No.2 0.1 1.07214 2.05 0.5 1.04682 1.78 1.0 1.02090 1.62 2.0 1.00804 1.45 3.0 0.99283 1.36 No.3 0.1 1.07412 2.06 0.5 1.05242 1.76 1.0 1.03982 1.61 2.0 1.02711 1.43 3.0 1.02072 1.33 表 4 堆芯优化方案参数
Table 4. Parameters of the optimal core
power/MW life/d number of fuel rods number of fuel rods with BP mass of fuel without BP/t mass of fuel with BP/t core mass/t 20 3 500 955 186 1.93 0.46 4.49 表 5 径向反射层各层厚度组合
Table 5. Different choices for subdividing the radial reflector
layering choice reflector thickness/cm first layer second layer third layer case 1 5 4 7 case 2 6 3 7 case 3 4 4 8 case 4 5 3 8 case 5 3 4 9 case 6 4 3 9 表 6 卡块事故分析
Table 6. Accident analysis of stuck sliders
state of outmost layer location of stuck slider shutdown margin/10−5 fixed B1 635 B1、B2 66 B5 895 B5、B6 305 withdrawn B1 6913 B1、B2 5693 B5 7123 B5、B6 6146 -
[1] Wollman M J, Zika M J. Prometheus project reactor module final report, for naval reactors information[R]. West Mifflin: Knolls Atomic Power Lab. , 2006. [2] Ashcroft J, Eshelman C. Summary of NR program Prometheus efforts[J]. AIP Conference Proceedings, 2007, 880(1): 497-521. [3] 郭凯伦, 王成龙, 秋穗正, 等. 兆瓦级核电推进系统布雷顿循环热电转换特性分析[J]. 原子能科学技术, 2019, 53(1):16-23Guo Kailun, Wang Chenglong, Qiu Suizheng, et al. Analysis on thermoelectric conversion characteristic of Brayton cycle in megawatt-class nuclear electric propulsion system[J]. Atomic Energy Science and Technology, 2019, 53(1): 16-23 [4] El-Genk M S, Tournier J M. Noble-gas binary mixtures for closed-Brayton-cycle space reactor power systems[J]. Journal of Propulsion and Power, 2007, 23(4): 863-873. doi: 10.2514/1.27664 [5] Zhou Biao, Ji Yu, Sun Jun, et al. Nusselt number correlation for turbulent heat transfer of helium–xenon gas mixtures[J]. Nuclear Science and Techniques, 2021, 32: 128. doi: 10.1007/s41365-021-00972-1 [6] Meng Tao, Tan Sichao, He Yuhao, et al. Preliminary design considerations of He-Xe mixture cooled space nuclear reactor[C]//Proceedings of the 26th International Conference on Nuclear Engineering. 2018: V009T16A012. [7] Li Zeguang, Sun Jun, Liu Malin, et al. Design of a hundred-kilowatt level integrated gas-cooled space nuclear reactor for deep space application[J]. Nuclear Engineering and Design, 2020, 361: 110569. doi: 10.1016/j.nucengdes.2020.110569 [8] Buden D. Summary of space nuclear reactor power systems, 1983--1992[R]. Idaho Falls: Idaho National Engineering Lab. , 1993. [9] Rhee H S, Wetch J R, Gunther N, et al. Space-R thermionic space nuclear power system with single cell incore thermionic fuel elements[J]. AIP Conference Proceedings, 1992, 246(1): 120-129. [10] Li Jian, Zhou Qin, Xia Yan, et al. Study on reactivity control strategies for the thermoelectric integrated space nuclear reactor[J]. Annals of Nuclear Energy, 2020, 145: 107607. doi: 10.1016/j.anucene.2020.107607 [11] Guan Chaoran, Chai Xiang, Zhang Tengfei, et al. Preliminary lightweight core design analysis of a micro-transportable gas-cooled thermal reactor[J]. International Journal of Energy Research, 2022, 46(12): 17416-17428. doi: 10.1002/er.8408 [12] El-Genk M S, Tournier J M. A review of refractory metal alloys and mechanically alloyed-oxide dispersion strengthened steels for space nuclear power systems[J]. Journal of Nuclear Materials, 2005, 340(1): 93-112. doi: 10.1016/j.jnucmat.2004.10.118 [13] 沈芷睿, 孙启政, 何东豪, 等. 基于BEAVRS基准题高保真建模的OpenMC程序和NECP-X程序的对比验证[J]. 核技术, 2022, 45:010602Shen Zhirui, Sun Qizheng, He Donghao, et al. Comparison and verification of NECP-X and OpenMC using high-fidelity BEAVRS benchmark models[J]. Nuclear Techniques, 2022, 45: 010602 [14] 于平安, 朱瑞安, 喻真烷, 等. 核反应堆热工分析[M]. 上海: 上海交通大学出版社, 2002Yu Ping’an, Zhu Ruian, Yu Zhenwan, et al. Thermal analysis of nuclear reactor[M]. Shanghai: Shanghai Jiaotong University Press, 2002 [15] 沈维道, 郑佩芝, 蒋淡安. 工程热力学[M]. 北京: 高等教育出版社, 1983Shen Weidao, Zheng Peizhi, Jiang Danan. Engineering thermodynamics[M]. Beijing: Higher Education Press, 1983 [16] Driscoll M J, Downar T J, Pilat E E. The linear reactivity model for nuclear fuel management[M]. La Grange Park: American Nuclear Society, 1990. [17] 刘思佳, 朱贵凤, 严睿, 等. 小型模块化氟盐冷却高温堆可燃毒物布置方案[J]. 核技术, 2020, 43:050602 doi: 10.11889/j.0253-3219.2020.hjs.43.050602Liu Sijia, Zhu Guifeng, Yan Rui, et al. Placement scheme of burnable poisons in a small modular fluoride-cooled high temperature reactor[J]. Nuclear Techniques, 2020, 43: 050602 doi: 10.11889/j.0253-3219.2020.hjs.43.050602 [18] Hossain T, Sahadath H, Nabila U M. Neutronic and fuel cycle performance of VVER-1000 for dual cooled annular fuel with coated burnable poison[J]. Progress in Nuclear Energy, 2022, 145: 104139. doi: 10.1016/j.pnucene.2022.104139 [19] 张成龙, 袁媛, 堵树宏, 等. 气冷微型堆可燃毒物研究[J]. 强激光与粒子束, 2022, 34:026010 doi: 10.11884/HPLPB202234.210264Zhang Chenglong, Yuan Yuan, Du Shuhong, et al. Research on burnable poison in micro gas-cooled reactor[J]. High Power Laser and Particle Beams, 2022, 34: 026010 doi: 10.11884/HPLPB202234.210264