The fouling and thermal hydraulic coupling study on the typical 5 × 5 rod bundle in PWRs

The state of the nuclear reactor core is significant, and the corrosion products will be deposited in the core, threatening its safety. In this paper, the analytical model of fouling deposition and migration process is established, and the core corrosion deposition-thermal-hydraulic coupling analysis method is proposed to study the fouling deposition and its effect on the flow and heat transfer state under the long-term operation of the typical 5 × 5 rod bundle channel. The results show that the established model is reasonable. The distribution of fouling in the bundle is related to the position. Under the operating conditions calculated in this paper, the amount of fouling in the outer layer bundle is higher than that in the inner layer. And the fouling rate is positively correlated with the wall temperature. The fouling rate will be greater in the place with higher wall temperature in the bundle. The content of this study could provide reference for the study of reactor core fouling and its heat transfer characteristics.