Simulation of the Natural Circulation Experiment in the PSB-VVER Test Facility Using the SOCRAT Code. Part 2. Simulation Results and Estimation of Modeling Errors
DOI:
https://doi.org/10.24160/1993-6982-2025-3-100-109Keywords:
SOCRAT code, natural circulation, mathematical simulation, experimental modeling, PSB-VVER test facility, code validation, nuclear power plant safety, thermal hydraulicsAbstract
This article is a continuation of the work “Numerical simulation of the natural circulation experiment in the PSB-VVER test facility using the SOCRAT code. Part 1. Analysis model development and verification”. The purpose of the study is to numerically simulate with the SOCRAT computer code the experiment on investigation of various natural circulation modes on the PSB-VVER large-scale integrated test facility. Single-phase and two-phase natural circulation of the coolant is the main mechanism of decay heat removal from the core to the steam generators during accidents involving leaks from the primary circuit of VVER reactors. The efficiency of natural circulation under the conditions of a partially filled primary coolant system is of crucial importance for the operation of passive safety systems during accidents accompanied by prolonged station blackout. To evaluate the SOCRAT code ability to model various natural circulation mechanisms and adequately predict the transition between modes, the natural circulation experiment conducted on the PSB-VVER integrated test facility was calculated. The test facility nodalization scheme was developed, including a reactor model, four circulation loops, a pressurizer and steam generators. The performed calculations simulated both the stage of coolant drainage from the primary system and its filling stage. Good agreement between the predicted and experimental results has been obtained for all of the main parameters characterizing the natural circulation. The boundaries of transitions between different natural circulation modes depending on the coolant mass inventory in the primary system are determined. The prediction error of the coolant mass at which the core heating starts is estimated. The obtained results are necessary for validation of the SOCRAT code as applied to safety analysis of VVER-type reactor plants.
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Для цитирования: Капустин А.В. Моделирование кодом СОКРАТ эксперимента по естественной циркуляции на стенде ПСБ-ВВЭР. Ч. 2. Результаты моделирования и оценка погрешности расчёта // Вестник МЭИ. 2025. № 3. С. 100—109. DOI: 10.24160/1993-6982-2025-3-100-109
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For citation: Kapustin A.V. Simulation of the Natural Circulation Experiment in the PSB-VVER Test Facility Using the SOCRAT Code. Part 2. Simulation Results and Estimation of Modeling Errors. Bulletin of MPEI. 2025;3:100—109. (in Russian). DOI: 10.24160/1993-6982-2025-3-100-109
