Cooling capability of remaining core fuel after core degradation in SFRs

Imaizumi, Yuya; Sogabe, Joji*; Onoda, Yuichi; Yamano, Hidemasa

Proceedings of 2025 International Congress on Advances in Nuclear Power Plants (ICAPP 2025) (Internet), 9 Pages, 2025/09

An Analysis of CABRI E7 experiment for validation of detailed fuel pin model in the SIMMER-V code

Ishida, Shinya; Tagami, Hirotaka*; Yamano, Hidemasa; Kubo, Shigenobu

Proceedings of 2025 International Congress on Advances in Nuclear Power Plants (ICAPP 2025) (Internet), 11 Pages, 2025/09

Validation study on SFR core bowing codes using Joyo ex-core experiment data; Single duct bowing benchmark

Ohgama, Kazuya; Doda, Norihiro; Ota, Hirokazu*; Wozniak, N.*; Uwaba, Tomoyuki; Futagami, Satoshi; Tanaka, Masaaki; Yamano, Hidemasa; Ogata, Takanari*; Shemon, E.*; et al.

Progress in Nuclear Science and Technology (Internet), 8, p.160 - 164, 2025/09

https://doi.org/10.15669/pnst.8.160

To enhance the accuracy of the safety evaluations for sodium-cooled fast reactors, it is necessary to develop a method that can realistically evaluate the reactivity changes induced by core deformation. In this context, Japan and the United States jointly conducted a benchmark analysis of thermal bowing experiments using a single duct from a Joyo-type fuel assembly. The aim was to confirm the validity of the core bowing analysis codes. Comparisons of analysis and experimental results demonstrated that the codes used by both countries were able to reasonably predict the axial distribution of horizontal duct displacement caused by thermal bowing as well as the contact load on the duct pad.

Risk assessment methodology for heat transfer tube failure in a sodium-molten salt heat exchanger for sodium-cooled fast reactor coupled to molten salt thermal energy storage system

Takano, Kazuya; Kurisaka, Kenichi; Yamano, Hidemasa

Progress in Nuclear Science and Technology (Internet), 8, p.82 - 85, 2025/09

https://doi.org/10.15669/pnst.8.82

As part of the development of risk assessment technologies for sodium-cooled fast reactor coupled to thermal energy storage (TES) system with sodium-molten salt heat exchanger (HX), the database on the number of heat transfer tube failure in molten salt HX and the exposure time of concentrated solar power (CSP) system to molten salt was surveyed on the basis of reported practices of accidents in the existing CSP systems with the molten salt TES system. Using the database, a risk assessment methodology of the heat transfer tube failure frequency was also studied with a Bayesian estimation method to obtain a risk insight for improving the HX.

Characterization of relocated solidified eutectic melt of BC-stainless steel composite under severe reactor conditions

Ahmed, Z.*; Kumar, R.*; Yokoyama, Ryo*; Okamoto, Koji*; Pellegrini, M.*; Yamano, Hidemasa

Proceedings of 21st International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-21) (Internet), 15 Pages, 2025/08

Seismic fragility evaluation of a thin-walled vessel in a sodium-cooled fast reactor

Watakabe, Tomoyoshi; Yamano, Hidemasa; Futagami, Satoshi

Transactions of the 28th International Conference on Structural Mechanics in Reactor Technology (SMiRT28) (Internet), 10 Pages, 2025/08

The fragility evaluation method of the RV in the SFR has been developed for both failure mode buckling and fatigue. The past studies showed the fragility using the RV of a loop-type SFR: radius R / thickness t is about 100. Recently, Japan Atomic Energy Agency together with Japanese industrial partners has been conducting a pool-type SFR design. The fragility of the pool-type RV has never been evaluated by the proposed method, which is based on the fatigue failure mode instead of the buckling. To investigate the basic behaviour of the pool-type RV under excessive seismic loading, this report investigated the fragility by using a simple cylindrical model with a wall thickness close to the design of the pool-type RV: R/t is 200, as the first trial.

Density, surface tension, and viscosity of molten Ni-based superalloys using the maximum bubble pressure and oscillating crucible methods

Nishi, Tsuyoshi*; Matsumoto, Saori*; Yamano, Hidemasa; Hayashi, Kiichiro*; Endo, Rie*; Bell, M. R.*; Neubert, L.*; Volkova, O.*

Steel Research International, 96(5), p.2300766_1 - 2300766_6, 2025/05

https://doi.org/10.1002/srin.202300766

The density of Ni-based superalloys is measured using the maximum bubble pressure (MBP) method. The viscosity is evaluated using the oscillating crucible method. The surface tension is simultaneously measured using the MBP method.

Density, surface tension, and viscosity of liquid low-sulfur manganese-boron steel via maximum bubble pressure and oscillating crucible methods

Bell, M. R.*; Neubert, L.*; Sherstneva, A.*; Yamamoto, Taisei*; Nishi, Tsuyoshi*; Yamano, Hidemasa; Weinberg, M.*; Volkova, O.*

Steel Research International, 96(5), p.2400252_1 - 2400252_10, 2025/05

https://doi.org/10.1002/srin.202400252

In this study, the thermophysical properties of low-sulfur manganese-boron steel with varying boron and sulfur contents at different temperatures are investigated.

Radiation heating effects on BC-SS eutectic melting and its relocation behaviour

Ahmed, Z.*; Sharma, A. K.*; Pellegrini, M.*; Yamano, Hidemasa; Okamoto, Koji*

Arabian Journal for Science and Engineering, 50(5), p.3361 - 3371, 2025/03

https://doi.org/10.1007/s13369-024-09412-9

First freezing experiments with a molten mixture of boron carbide and stainless steel in core disruptive accidents of sodium-cooled fast reactors

Emura, Yuki; Matsuba, Kenichi; Kikuchi, Shin; Yamano, Hidemasa

Proceedings of 13th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS13) (Internet), 8 Pages, 2024/11