Modeling and Applicability Analysis of Nitrogen Pressurization System Based on RELAP5

Jiang Meng; Liu Mengjuan; Zhao Meng; Huang Li; Yang Yanhua; Zhao Jiangang

doi:10.13832/j.jnpe.2024.090023

Volume 46 Issue 5

Oct. 2025

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Jiang Meng, Liu Mengjuan, Zhao Meng, Huang Li, Yang Yanhua, Zhao Jiangang. Modeling and Applicability Analysis of Nitrogen Pressurization System Based on RELAP5[J]. Nuclear Power Engineering, 2025, 46(5): 30-36. doi: 10.13832/j.jnpe.2024.090023

Citation:

Jiang Meng, Liu Mengjuan, Zhao Meng, Huang Li, Yang Yanhua, Zhao Jiangang. Modeling and Applicability Analysis of Nitrogen Pressurization System Based on RELAP5[J]. Nuclear Power Engineering, 2025, 46(5): 30-36. doi: 10.13832/j.jnpe.2024.090023

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Modeling and Applicability Analysis of Nitrogen Pressurization System Based on RELAP5

doi: 10.13832/j.jnpe.2024.090023

1.
College of Smart Energy, Shanghai Jiao Tong University, Shanghai, 200240, China
2.
China Nuclear Power Technology Research Institute Co., Ltd., Shenzhen, Guangdong, 518000, China
3.
School of Nuclear Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China

Received Date: 2024-09-14
Rev Recd Date: 2024-11-20

Available Online: 2025-10-15

Publish Date: 2025-10-15

Abstract

Abstract

In order to explore the operational characteristics of the nitrogen pressurization system, this study employed RELAP5 for computational simulation and conducted an applicability analysis of the code's nitrogen pressurization model. The results indicate that RELAP5 exhibits the following errors when simulating the nitrogen pressurization system: normalized pressurizer pressure and water level are overestimated; excessive temperature gradient in the fluid region; and excessive temperature in the gas region. Analysis shows that the reasons for the calculation errors in RELAP5 may include: the energy equation does not contain the axial heat diffusion term; the high-concentration non-condensable gas partial pressure exceeds the model's applicable range; limited applicability of wall heat transfer models; and missing material properties. Based on existing research findings, the model modification involves incorporating a thermal diffusion characterization term and modifying the nitrogen-water heat exchange model, with emphasis placed on addressing the nitrogen-water heat exchange issue which has a greater impact on the results.
- Nitrogen pressurization,
- System code,
- RELAP5,
- Applicability analysis

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References(11)

References

[1]	林千. 小型一体化压水堆主设备设计比较研究[J]. 发电设备, 2017, 31(3): 171-175. doi: 10.3969/j.issn.1671-086X.2017.03.007
[2]	闫新龙, 李毅, 罗涵禹, 等. 一回路氮气稳压系统瞬态模拟研究[J]. 核动力工程, 2022, 43(3): 33-37.
[3]	赵巍, 王少明. 新型船用气体稳压器启动充气过程的建模及仿真研究[J]. 海军工程大学学报, 2005, 17(6): 99-101, 107. doi: 10.3969/j.issn.1009-3486.2005.06.020
[4]	张伟, 夏国清. 新型船用氮气稳压器控制方法研究[J]. 应用科技, 2004, 31(12): 49-51. doi: 10.3969/j.issn.1009-671X.2004.12.018
[5]	张大林, 秋穗正, 苟军利, 等. 新型氮气稳压器系统稳态和瞬态特性研究[J]. 核动力工程, 2006, 27(S1): 38-42.
[6]	WU Y W, SU G H, QIU S Z, et al. Development of a thermal–hydraulic analysis software for a passive residual heat removal system[J]. Annals of Nuclear Energy, 2012, 48: 25-39. doi: 10.1016/j.anucene.2012.05.012
[7]	XIAO Y, WU Y W, TIAN W X, et al. Development of VTSAS 1.0 and application to an IPWR[J]. Nuclear Engineering and Design, 2013, 261: 20-32. doi: 10.1016/j.nucengdes.2013.02.043
[8]	RANSOM V H. Course A-numerical modeling of two-phase flows for presentation at Ecole d'Ete d'Analyse Numerique: EGG-EAST-8546[R]. Idaho Falls: EG and G Idaho, Inc. , 1989.
[9]	The RELAP5 Development Team. RELAP5/MOD3 code manual. volume 4, models and correlations: NUREG/CR-5535[R]. Idaho Falls: Idaho National Engineering Laboratory, 1995.
[10]	CORYELL E W. SCDAP/RELAP5/MOD 3.1 code manual: interface theory: NUREG/CR-6150[R]. Idaho Falls: Idaho National Engineering Laboratory, 1995.
[11]	VIEROW K M, SCHROCK V E. Condensation in a natural circulation loop with noncondensable gases, 1[C]//Proceedings of the International Conference on Multiphase Flows’91. Tsukuba: Japan Society of Multiphase Flow, 1991.