Three-dimensional modeling and loss-of-coolant accident analysis of high temperature gas cooled reactor

The high temperature gas-cooled reactor (HTR) is well known due to its prominent inherent safety, high efficiency and low carbon environmental protection. Accurate and reliable thermal hydraulic analysis is of great significance to the system design of HTR. Based on the coolant flow and heat transfer process in the core, this study establishes a three-dimensional coupled model for the core of HTR, and the temperature variation in the core is simulated. The model is verified by comparing the calculated results with those published data by THERMIX software. After that, the models are employed to study thermal hydraulic characteristics under the loss of coolant accident. The results show that the maximum relative error of the calculated results with published data are 2.1% under full power, the three-dimensional model can be employed to simulate the flow and heat transfer process in the primary circuit of HTR. The calculation of 50% of full power shows that the model fully considers the influence of convective heat transfer and radiative heat transfer between the core of the pebble bed and the core side wall and the cold air chamber, making numerical calculations closer to actual condition. It is found when approximately 20% of the coolant is lost, the outlet temperature of helium reaches 1140 K, which exceeds the helium outlet temperature limit (1126 K). In addition, the inherent safety of an HTR be verified under transient conditions of natural convection. Keywords: High temperature gas-cooled reactor Thermal hydraulics analysis Loss of coolant accident Numerical simulation (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study established a three-dimensional coupled model for the core of high temperature gas-cooled reactor and verified it by comparing calculated results with published data, which showed that the model can be used to simulate flow and heat transfer process in the primary circuit effectively. It was found that the model fully considers the influence of convective and radiative heat transfer, making numerical calculations closer to actual condition.