Facility Details: DEFOR-A

Organization / Localization: KTH-NPS
Facility Description: The facility is composed of a 45-kW medium frequency (up to 30kHz)induction furnace (IF) for melt generation, melt delivery funnel, andcoolant tank with a glass window for visual imaging of transientpre-mixing.
Test Identification: A23 - 27
SA-Related Topics / Phenomena: Oxidic simulant melt fragmentation and debris bed formation in deep water pool
Measured Parameters: Debris bed 3D scanning, agglomeration fraction as pool depth function, particle size distribution as pool depth function, debris bed porosity estimate
Modelling: Melt jet breakup
Simulation Code: JBREAK; CLSVOF; COCOMO
Experimental Research Program: (i) Experimental program "Invstigation of Cooling Phenomena of High Temperature Molten Core" for Nuclear regulation Authority (NRA) of Japan; (ii) EU SAFEST; National program "Accident Phenomena of Risk Importance" (APRI) supported by consortium of SSM an
Link to PIRT:  
References: [1] Wataru Kikuchi, Akitoshi Hotta, Koetsu Ito, Mamoru Shimizu, Development of an evaluation method for debris bed formation behavior focusing on the agglomeration mechanism observed in the DEFOR-A test using THERMOS/JBREAK–DPCOOL–MSPREAD, Nuclear Engineering and Design, Volume 439, 2025, 114041, https://doi.org/10.1016/j.nucengdes.2025.114041
[2] Akitoshi Hotta, Miyuki Akiba, Akinobu Morita, Alexander Konovalenko, Walter Villanueva, Sevostian Bechta, Andrei Komlev, Sachin Thakre, Seyed Mohsen Hoseyni, Per Sköld, Toshinori Matsumoto, Tomoyuki Sugiyama & Michael Buck, “Experimental and Analytical Investigation of Formation and Cooling Phenomena in High Temperature Debris Bed”, Journal of Nuclear Science and Technology, 57:4, 353-369, 2019, DOI: 10.1080/00223131.2019.1691078
IP/Copyright Situation: None




Implemented as part of the Seaknot EU funded project (HORIZON-EURATOM-2021-NRT-01 under Grant Agreement No. 101060327) - WP2.6 UNIPI (2024-2026)