Backward phenomenon on natural circulation flow based on power differences in FASSIP-01 loop

• Main Authors: Juarsa, Mulya, Antariksawan, Anhar R., Widodo, Surip, Kusuma, M. Hadi, Rohman, Agus Nur, Giarno, Subki, M. Hadid
• Format: Conference Proceeding
• Language: English
• Subjects: Cooling systems; Density; Experiments; Flow velocity; Fluid dynamics; Fluid flow; Hydraulics; Nuclear engineering; Nuclear safety; Pipes; R&D; Reactor safety; Research & development; Test facilities; Thermal management; Water circulation; Water flow; Water temperature
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.5049996

The R&D of thermal-hydraulics for passive cooling system to optimize thermal management during the accident and operation of NPP become an important research topics related to the improvement of the accident management of NPP. The need for experimental research using medium scale test facilities becomes an important need to investigate passive cooling systems for improved reactor safety. FASSIP-01 Loop is a medium scale test facility which water inside the rectangular loop which the water flow is driven by natural circulation due to the differences of density in heater area and in the cooler area. The purpose of this experiment is to investigate the natural circulation phenomenon during start-up condition since the beginning until stable flow. The experiment has been done with heater power variation is 4845 watt and 5928 watt, the flow rate variation in cooler area is 10.38 LPM and 43.10 LPM with the pipe of rectangular loop was not isolated. The result of experiment from 0 s to 5000 s shows the backward phenomenon which was occurs due to decrease in water temperature near the pipe wall. The backward flow point difference between two heater powers is 0.0165 LPM for coolant flow of 10.38 LPM and 0.0088 LPM for coolant flow of 43.10 LPM. The density of water in cross section of rectangular pipe is not the same for a few times.