PLANDTL-2 experiment for evaluation of decay heat removal in sodium-cooled fast reactors; Effect of inter-subassembly gap flow under interruption of flow through fuel assemblies

Ezure, Toshiki ; Akimoto, Yuta ; Tsuji, Mitsuyo ; Kurihara, Akikazu ; Tanaka, Masaaki  

Sodium experiments using PLANDTL-2 test facility, which have multiple rows of simulated core, have been carried out to clarify the decay heat removal characteristics inside a reactor. In this study, decay heat removal experiments were carried out using a dipped-direct heat exchanger under no primary flow rate conditions and interrupting the flow through the assemblies by a plugging system of fuel assemblies. As the results, the influence of inter-subassembly gap flow on the cooling characteristics of simulated core was clarified.