Heat pipe cooling system reliability analysis with cascading effect

초록

In recent years, there have been lots of research and developments about micro reactors. Heat pipe cooled reactor is considered as one of strong candidates for micro reactors due to passive operation capability. Because heat pipe cooling system consists of multiple heat pipes and the heat pipes share the thermal load of the system, the system has redundancy and therefore high reliability. Even though single failure of heat pipe may not lead to system failure, however, the system may fail when multiple heat pipes fail. Therefore, the cascading heat pipe failure is one of major safety issues in heat pipe cooled reactors. If a single heat pipe fails, the thermal load of failed heat pipe is distributed to adjacent heat pipes and the adjacent heat pipes are more likely to fail. Because cascading effect highly affect the reliability of the system, the reliability analysis for heat pipe cooling system should reflect the cascading effect. In this paper, the heat pipe cooling system is modeled as continuous and state dependent process to reflect cascading effect. Then, the mathematical model for the failure time of heat pipe cooling system is proposed and the reliability of the system is estimated based on the model. Furthermore, the source of uncertainties for the reliability of the system are identified and the uncertainty analysis is performed. © 2023 Proceedings of the 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2023. All rights reserved.

키워드