An experimental investigation on CCFL characteristics during gas/low surface tension liquid counter-current two-phase flow in a small-scaling PWR hot leg typical geometry

¹ Department of Mechanical Engineering, Universitas Sanata Dharma, Kampus III USD Maguwoharjo, Yogyakarta 55282, Indonesia
² Department of Mechanical and Industrial Engineering, Universitas Gadjah Mada, Jalan Grafika No 2 Kampus UGM, Yogyakarta 55281, Indonesia
³ Centre for Smart Technology Studies, Universitas Sanata Dharma, Kampus III USD Maguwoharjo, Yogyakarta 55282, Indonesia
⁴ Centre for Energy Studies, Universitas Gadjah Mada, Sekip K-1A Kampus UGM, Yogyakarta 55281, Indonesia

^* Corresponding author: author@email.org

Abstract

A sharp increase in world energy demands which further results in another large progress in the development of nuclear energy establishes comprehensive developments on corresponding mitigation studies. Therefore, as a scenario of accident called LOCA is fundamentally considered, the related phenomena, i.e., the counter-current flow followed by flooding in the primary circuit of PWR, is of a great importance. The present work investigates characteristics of the flooding during a pair of gas/low surface tension liquid counter-current two-phase flow in a complex conduit representing a down-scaled of PWR hot leg typical geometry. Visual observations were obviously carried out to observe the flow phenomenology, while flow parameters were frequently varied. A typical result reveals that the gas flow rate to initiate the flooding decreases with the increase of liquid flow rate. Moreover, exhibiting locations of the onset called locus, a front flooding tends to occur during relatively low liquid flow rates while the higher liquid flow rates exhibit another flooding namely rear flooding. Accordingly, the present investigation provides a package of valuable information on a particular understanding towards the flooding characteristics to overcome the efforts on promoting safety managements on the operation of nuclear power plants..