Session: 07-04: Experiments and Analyses - III

Paper Number: 135143

135143 - Simulation and Analysis for Hualong Reactor Advanced Integrated Test Facility Based on Relap5 

Abstract: 

The Hualong One and its subsequent rectors are the third-generation pressurized water reactor (PWR) nuclear power technologies designed and constructed by the China Nuclear Power Engineering (CNPE) which possess completely independent intellectual property rights. China Nuclear Power Engineering Co., Ltd. designed and built an integrated test facility for the Hualong's subsequent rectors emergency core cooling system (referred as Integrated Test Facility). The Integrated Test Facility is a large-scaled facility and designed based on the Hualong's subsequent rectors and safety systems, which adopts a passive safety design concept. The Integrated Test Facility includes High-Pressure Makeup Tank (HPMT), Accumulator (ACC), Automatic Depressurization System (ADS), Outside Reactor Water Storage Tank (ORWST), Direct Vessel Injection (DVI) pipeline, Sump, Passive Residual Heat Removal System (PRS), Passive Containment Cooling System (PCS), etc. These systems and equipment work together to achieve passive emergency core cooling function. In this paper, a RELAP5 model is establish to analyze a small LOCA accident sequence. Simulations are conducted for five stages after the accident, including natural circulation, automatic depressurization, injection from the outside reactor water storage tank, and long-term sump recirculation. A 4MW core power steady-state calculation (with operation pressure 15.5MPa, the core inlet temperature is 294.4 Celsius degrees and the core outlet temperature is 327.7 Celsius degrees) and medium pressure model was established, and model parameter sensitivity analysis was conducted, including different core flow rates, different cold and hot leg breach locations, different loop breaches, RPPS-4 single failure, pressure vessel bypass flow, HPMT balance pipeline arrangement, ORWST gravity injection, etc. Simulation models were used to perform thermal distortion calculations in the integrated test facility key structures, including the primary loop, HPMT, fuel rods, and SG heat transfer tubes. The emergency core cooling system operational characteristics were investigated under different breach conditions (such as 1-10 inch breach in the cold leg, 2-inch breach in the hot leg), double-ended break in Direct Vessel Injection (DVI), double-ended break of Primary Boundary Leak (PBL), and inadvertent opening of Reactor Pressure Power Supply (RPPS) in accident scenarios. The simulation results demonstrated that the RELAP5 model can simulate the transient key system parameters accurately after breach accident. This paper investigates the operational characteristics of the emergency core cooling system under different breach conditions, elucidates the interaction mechanisms of various passive safety systems, and explores the physical mechanisms of thermal-hydraulic phenomena and processes in the integrated test facility. Based on numerical simulation analysis, the experimental data under accident conditions are obtained, thereby validating the rationality of the safety system design for the integrated test facility and the effectiveness of the accident analysis modeling method.

Presenting Author: Yiwa Geng China Nuclear Power Engineering Co., Ltd.

Presenting Author Biography: Geng Yiwa, Ph.D., Her current research interests are nuclear reactor thermal hydraulics and accident analysis. She has published 4 papers in core journals and SCI

Authors:

Yiwa Geng China Nuclear Power Engineering Co., Ltd.
Jingxiang Zhan China Nuclear Power Engineering Co., Ltd.
Yuntao Zheng China Nuclear Power Engineering Co., Ltd.
Jiatai Liu China Nuclear Power Engineering Co., Ltd.
Shuliang Huang China Nuclear Power Engineering Co., Ltd.
Si Ni China Nuclear Power Engineering Co., Ltd.
Changjiang Yang China Nuclear Power Engineering Co., Ltd.